Edelbrock Pro-Flo EFI System Installation Instructions

Introduction

Thank you for selecting the Edelbrock Pro-Flo Fuel Injection System. This Multi-Point Fuel Injection System is designed for 350 c.i.d. small-block Chevrolet engines, providing excellent performance, fuel economy, and maintenance-free operation. Installation involves modifications to the fuel system, ignition system, induction system, and possibly the valve train. Study these instructions carefully before beginning installation.

Calibration Chips

The Pro-Flo Fuel Injection System is shipped without the computer chip. The chip is necessary to operate the ECU. If the cam is not an Edelbrock brand, check with the manufacturer for compatibility with EFI. Complete the Chip Information Card and return it to Edelbrock. Edelbrock will send the computer chip within the continental U.S. via UPS second day air. Orders outside the continental U.S. will be shipped via the best method at the same costs as continental UPS second day air. Customers may pay for expedited shipping by providing a current Visa or Master Card. The chip installs into the System Computer in minutes. Additional chips are available for a nominal charge for different cam profiles. If you have questions, contact Edelbrock.

EFI Technical Hotline: (800) 416-8628 (Monday-Friday, 7am-5pm PST)

Email: EFItech@edelbrock.com

Components

The Pro-Flo system includes the following components:

• Electronic Control Unit/System ECU
• Calibration Module
• Distributor Conversion Kit
• Ignition Amplifier
• ECU Power Relay/Fuel Pump Relay
• Manifold Absolute Pressure (MAP) Sensor
• Manifold Air Temperature (MAT) Sensor
• Coolant Temperature Sensor (CTS)
• Throttle Position Sensor (TPS), Integrated with Air Valve
• Oxygen (O2) Sensor
• High Pressure Fuel Pump
• Fuel Filter
• Fuel Rail Assembly
• Fuel Pressure Regulator
• Fuel Injectors
• Intake Manifold
• Four-Barrel Air Valve
• Idle Air Control (IAC) Solenoid, Integrated with Air Valve
• Main System Harness
• Fuel Pump Harness
• Installation Package

Many Pro-Flo components, such as the Manifold Absolute Pressure sensor, fuel pressure regulator, Coolant Temperature sensor, and fuel filter are standard OEM parts. Replacements can be found at your local parts supplier, Edelbrock dealer, or directly from Edelbrock.

Tools and Equipment

The following tools and equipment are recommended for installation:

• Box and open end wrenches
• Socket set
• Distributor wrench
• Pliers (channel locks and hose clamp)
• Screwdrivers (regular and Phillips)
• Torque wrench
• Hammer
• Gasket scraper or putty knife
• Timing light
• Vacuum gauge
• Rags
• Water bucket
• Harmonic balancer puller
• Dial indicator
• Drill and bits
• Hole saw (1 1/4-inch or 1 3/4-inch)
• Tubing wrenches
• Tubing cutter

Hardware and Parts Recommended

• Gaskets - Edelbrock, OEM, or equivalent
• Pipe plugs, if needed
• 5/16-inch steel tubing (approximate equal length to fuel pickup line in tank)
• Edelbrock Gasgacinch #9300
• Loctite 598 OEM High Temperature Silicone Gasket (O2 Sensor Compatible)
• Radiator coolant
• Edelbrock Teflon thread tape #9275
• Intake gasket #3500/3503 use #7201, for #3507 use factory gasket set for 1998 pick up
• Manifold bolt kit #3500/3503 use #8504, for #3507 use factory bolt kit.
• Throttle, Cruise Control & Trans. Kick-Down Mounting Bracket #8036 (If Necessary)
• Wiring diagram for your vehicle

Preliminary Check List

1. Carefully study and understand all instructions.
2. Examine the Pro-Flo system for possible shipping damage. Contact your dealer immediately if damage is found.
3. Check all threaded manifold holes.
4. Check all internal manifold passages with a light and wire, ensuring they are clean and unobstructed.
5. Check automatic transmission shift points before removing the stock manifold and adjust linkage after Edelbrock manifold installation for the same shift points (if needed).

Note: Refer to this checklist again after installation to ensure all steps are completed.

Determining Hood Clearance

Note: Check hood clearance before removing the stock manifold.

1. Use modeling clay or putty to make five small cones, two or three inches high.
2. Position cones on the air cleaner at the front, rear, each side, and on the center stud.
3. Close the hood to the locked position and re-open.
4. The height of the cones indicates the clearance between the hood and the air cleaner. Record these measurements.

Manifold & Carburetor Height vs. Pro-Flo Height

1. Remove air cleaner.
2. Lay a straightedge (such as a yardstick) across the top of the carburetor from front to back.
3. Measure from the block and manifold end seal surfaces to the straightedge.
4. Record these measurements (height A and height B).
5. Add height A and height B and divide by two to get the average height.
6. The Pro-Flo manifold and air valve measures:
• #3500: A = 5.30", B = 5.30" + Air Valve 2.25"
• #3503: A = 4.10", B = 5.50" + Air Valve 2.66"
• #3503: A = 4.10", B = 5.50" + Air Valve 2.25"
7. Compare the two measurements. If the Pro-Flo unit is taller, subtract this amount from the hood clearance figure to determine new hood clearance.

CAUTION: Maintain at least 1/2-inch clearance between the hood and air cleaner due to engine torque. If clearance is insufficient, a low profile air cleaner may solve the problem.

Emission Controls

The Edelbrock Pro-Flo system will not accept stock emissions control systems. Check local laws for requirements before installing the Pro-Flo system. Not legal on pollution-controlled motor vehicles.

Fuel Requirements

The Pro-Flo system uses an Oxygen sensor, requiring unleaded fuel only. Leaded fuels will damage the O2 sensor. If leaded fuel is used, do not install the O2 sensor and do not operate the vehicle in closed loop fuel mode.

Automatic Transmission Check

For best performance, economy, and emissions, check the shift point before and after the manifold change. This check should be performed ONLY at a sanctioned drag strip or test track.

With the shifter in Drive, accelerate to wide open throttle from a standing start. Note the speedometer MPH when the transmission makes the first 1-2 shift. After Pro-Flo system installation, repeat the test and note the MPH of this first shift.

If adjustment is necessary, Edelbrock recommends using the Edelbrock Throttle, Cruise Control, & Transmission Kick-Down Mounting Bracket #8031 or #8032 with Vortec heads. The Turbo 350 and Turbo 200 feature a window for user adjustment of shift points at WOT. The 200 R4 and 700 R4 transmissions on late model vehicles require precise adjustments. Consult a reputable transmission shop for final adjustments after Pro-Flo system installation. Incorrect shift points can result in transmission damage.

Engine Cleaning

Edelbrock recommends installing the Pro-Flo system on a clean engine to prevent dirt from falling into the engine lifter valley or intake ports.

1. Cover ignition. Use engine de-greaser and a brush to thoroughly clean the manifold and the area between the manifold and valve covers.
2. Rinse with water and blow dry.

Exhaust Manifold Heat Riser Valve

If your vehicle is equipped with an exhaust manifold heat riser valve (typically located on the passenger side of the vehicle below the exhaust manifold), remove the valve for proper operation.

Headers

For best performance, headers are recommended. For this application, header primary tube diameter should be 1-3/4 inch, approximately 31 inches long and terminating into a 3-inch collector. The remainder of the exhaust system should consist of dual exhaust and tail pipes, at least 2-1/4 inches in diameter with low back pressure mufflers.

Cooling System

The minimum requirement for the thermostat is 180°, but the ideal thermostat is 195°. When the vehicle is at 175° or below, the system will stay in cold start mode and not perform properly.

Electronic Engine Management

The Edelbrock Pro-Flo system uses the Speed-Density method of electronic engine management, basing fuel and spark requirements on engine speed (RPM) and engine load (manifold pressure and temperature). The Electronic Control Unit (ECU) receives signals regarding engine speed (from the distributor), coolant temperature (ECT), Manifold Absolute Pressure (MAP), and air temperature (MAT). The ECU uses programmed tables to calculate spark advance and injector pulse width.

A more detailed description is in the Owner's Manual. The Pro-Flo system displays vacuum rather than manifold pressure. This vacuum reading is based on the SAE standard atmosphere: Barometer 29.5 in Hg, Temperature 77°F. Vacuum figures may differ from a true vacuum gauge at extreme altitudes.

Fuel Modifier Table and Spark Modifier Table are used for calibration. These tables come pre-set from the factory but can be altered with the Calibration Module to optimize performance. The Calibration Module allows modification of fuel and spark tables at various engine speeds and vacuum levels.

Sensors

The Pro-Flo system interprets engine operating conditions and fuel/spark requirements based on readings from five sensors:

1. Manifold Absolute Pressure
2. Manifold Air Temperature
3. Coolant Temperature
4. Throttle Position
5. Exhaust Oxygen (O2)

The O2 sensor must be installed on the exhaust pipe near the engine with a welded fitting.

Manifold Absolute Pressure Sensor

Mounted on the air valve with a bracket, this sensor converts air pressure (load) in the manifold to an analog signal sent to the ECU. It connects to the Main System Harness by Connector J9.

Manifold Air Temperature Sensor

This thermistor device measures air temperature. It must be installed into the air cleaner base. Drill the air cleaner base with a 3/4" drill, deburr edges, install the MAT sensor grommet, then slide the sensor into the grommet. It connects to the Main System Harness by connector J11.

Note: If the MAT sensor is in the intake plenum area, it can be moved to the air cleaner if necessary to obtain additional vacuum ports.

Coolant Temperature Sensor

This thermistor device's resistance varies with coolant temperature. It is located at the front of the manifold on the driver's side and connects to the Main System Harness by Connector J10.

Throttle Position Sensor

An integral part of the Pro-Flo throttle body, this sensor measures throttle angle. Adjustment is described in the SYSTEM START-UP section. It connects to the Main System Harness by Connector J8.

Oxygen (O2) Sensor

Installed on the header collector pipe, this sensor measures exhaust gas oxygen content to help the ECU manage fuel delivery under closed loop control. Installing the sensor requires drilling a 1/2-inch hole in the passenger-side header collector and welding in the provided fitting. The red-lean/green-rich light on the Calibration Module is controlled by the O2 sensor. It connects to the Main System Harness by Connector J21. For installation details, refer to the FUEL SYSTEM section.

Note: Prior to installing the O2 sensor, check the wires leading into the weather pack plug and ensure the odd colored wire is in the middle.

Ignition System

A new distributor is not required. The Pro-Flo system allows conversion of a stock distributor into a Multi-Port Fuel Injection-compatible Hall effect electronic distributor.

Hall Effect Sensor

A Hall effect distributor operates with a sensor that generates a pulse train indicative of engine position and speed, required for sequential fuel injection and accurate ignition timing. The Pro-Flo system includes components for this conversion: Hall effect sensor, sensor plate, and shutter wheel. A mechanical advance lock-out plate is also provided.

Shutter Wheel

The Hall effect shutter wheel has seven wide shutter teeth and one narrow shutter tooth. The narrow tooth indicates the Number One cylinder position, crucial for phasing the injector firing order. Correct installation is vital; incorrect installation will result in the wrong injector firing order.

Distributor Conversion

1. Rotate the engine to 10° Before Top Dead Center (BTDC) on cylinder #1, with the rotor pointing to the Number One cylinder plug wire.
2. Remove the distributor cap.
3. Remove the distributor from the engine.
4. Note the rotor's position and mark the distributor housing where the rotor points to Number One cylinder.
5. Remove the roll pin from the bottom of the distributor shaft, releasing the drive gear and shims.
6. Note: Check the drive gear and oil pump drive shaft for wear. Worn parts can damage the camshaft and oil pump.
7. Remove the rotor and distributor shaft.
8. Remove all internal components from the distributor housing, including the vacuum advance diaphragm.
9. Install the electronic Hall effect sensor and sensor plate using the provided fasteners. The sensor plate is designed for small or large cap distributors. For small cap distributors, move the sensor to other mounting holes.
10. Note: Ensure the sensor plate fits securely and is level in relation to the distributor housing.
11. Install the shutter wheel on the bottom of the rotor mounting plate, from the drive gear end of the rotor shaft. Fasten with two screws. On small cap distributors, install the provided aluminum ring spacer above the shutter wheel. The notched end of the rotor mounting plate should be farther from the narrow shutter tooth.
12. Note: On small cap distributors, file the stud holes of the shutter wheel to fit.
13. If converting a mechanical advance distributor, discard the advance weights. Replace them with the provided lock-out plate or weld. Secure the lock-out plate with stock springs. Tig welding the shaft to the rotor plate is recommended. Alternatively, apply RTV silicone to the underside of the rotor plate and studs before installing the lock-out plate.
14. Reinstall the distributor shaft. The shutter wheel teeth should pass through the Hall effect sensor without touching. Adjust by hand if necessary.
15. When the drive gear is installed, the shutter wheel teeth must be deep enough into the Hall effect sensor to pass through it at the proper depth, but not so deep as to make contact. On small cap distributors, use the provided spacer for correct spacing. On large cap distributors, use diamond-shaped shims for shutter wheel height adjustment.
16. Install the drive gear, shims, and roll pin to the bottom of the distributor shaft. Shaft end play should be .015" to .030".
17. Hand turn the rotor to ensure the shutter wheel is deep enough into the sensor without binding and check clearance between shutter wheel teeth and sensor. Shutter wheel teeth should not extend out of the tapered area of the sensor.
18. If clearance is correct, attach the rotor with supplied lock washers and nuts. Thread sealing compound is recommended.
19. When installing the shutter wheel and re-attaching the rotor, ensure the leading edge of the narrow shutter wheel tooth is centered in the Hall effect sensor when the rotor points to the Number One cylinder position.
20. Test your distributor before re-installation.

Small Cap Distributor Conversion

Adapting a small cap distributor requires additional steps:

1. The Hall effect sensor mounts with different fastening holes on a small cap distributor. Refer to Step 8 for correct sensor position.
2. The small cap distributor requires the installation of the provided spacer above the shutter wheel. Refer to Step 11.
3. To use the shutter wheel on small cap distributors, file the stud holes approximately 0.030-inch to fit the provided fasteners. This provides clearance between fillister screw heads and teeth. On some distributors, file screw heads to clear the top of the hall sensor.
4. To use the Pro-Flo system with a small cap distributor or any distributor with an external ignition coil, modify the 3-foot ignition amplifier harness. Refer to page 23 for details.

Distributor Testing

Before re-installing the distributor, test the conversion:

1. Install the ECU and wiring harness, making all connections except the distributor.
2. Disconnect electrical connections at the fuel pump. Unplug the 10-foot fuel pump harness from the Main System Harness.
3. Turn the key to the ON position without starting the engine. The Idle Air Control (IAC) solenoid should click on and off for approximately 2 seconds.
4. The Pro-Flo Calibration Module will power on and display RPM: 0, among other parameters.
5. Connect the distributor to the wiring harness and spin the distributor gear by hand. The calibration Module should display an RPM reading greater than 0 if the sensor is operating properly. When the distributor stops spinning, the module may display NO COMMUNICATION for approximately 2 seconds, indicating the ECU is waiting for the next distributor signal.
6. If an RPM greater than zero is indicated, re-install the distributor.

Reinstalling the Distributor

1. Ensure the distributor sits completely down on the manifold boss and the drive gear has fully engaged the oil pump drive.
2. Check rotor endplay by lifting the rotor by hand. Lack of endplay means the rotor shaft is bottomed out on the oil pump shaft.
3. Add gaskets at the bottom of the distributor shaft above the drive gear to adjust endplay. Recommended endplay is between 0.015- and 0.030- inch.
4. Adjust the housing so the leading edge of the narrow shutter wheel tooth is centered in the Hall effect sensor when the engine is at 10° BTDC on #1 cylinder.
5. Lightly tighten the hold down clamp to allow distributor rotation for final timing adjustment.
6. Re-attach the distributor cap, with the rotor pointing towards the No. 1 terminal.
7. Connect the distributor to the Main System Harness with connector J12.
8. A short ignition harness connects the distributor cap to the ignition amplifier and to ground at the rear of the cylinder head. A second connector connects the distributor cap to a 12-volt vehicle source (Start/Run source, BAT terminal on HEI). Refer to page 23 for details.

Ignition Amplifier

The Pro-Flo system uses the Edelbrock #3518 Ignition Amplifier, which must be mounted on a flat surface in the engine compartment away from exhaust headers or heat-generating areas. Ideal locations include the wheel well panel and firewall. The ignition amplifier has two connectors: Connector A (left) connects to Connector J26 on the main system harness. Connector B (right) connects to the 3-foot harness running to the distributor. See the wiring diagram in the MAIN SYSTEM HARNESS section.

Fuel System

The Pro-Flo system controls fuel delivery differently than a carburetor, requiring some fuel system conversions. Pro-Flo electronic fuel injection requires high and constant fuel volume and pressure. A 3/8-inch high pressure fuel line must be used as the primary fuel line. The fuel bypassing the injectors must be returned to the fuel tank via a return fuel line. If your vehicle has a fuel pump bypass line, it can be used as the return line. If not, the original primary line can be used as the return line. An 8-foot length of 5/16 ID rubber hose is supplied for the return line.

Many late-model cars have an additional fuel line to a charcoal canister. This line must be re-installed after fuel system conversion and must NOT be used as the return fuel line.

Fuel Pump and Filter

The Pro-Flo system uses a single Edelbrock high-pressure electric fuel pump capable of pumping 50 psi. The pump relay shuts down the pump if it does not receive an engine-run signal from the ECU, as in the case of a stall. The provided fuel filter should be mounted between the engine compartment and the fuel pump to allow fuel to be pushed through the filter. Electrical connectors should face the front of the vehicle.

Fuel Pressure Regulator

Fuel pressure is critical in fuel injection. The Pro-Flo fuel pressure regulator maintains constant pressure at the injectors with a spring-loaded by-pass to the return fuel line. Manifold Absolute Pressure references the regulator diaphragm to maintain constant pressure across all 8 injectors, regardless of fluctuating manifold pressure (vacuum). Uninjected fuel returns to the fuel tank via the return fuel line.

Return Fuel Line

Due to high fuel pressure, the supplied 3/8-inch high pressure fuel line MUST be used as the primary fuel line, and a bypass fuel return line must be installed. There are three options for installing a bypass return line:

1. Use the 5/16 rubber fuel line provided with the system as the fuel return line.
2. Use the vehicle's existing primary line as the fuel return line with modification to the pick up.
3. Use the vehicle's existing return line (if equipped). This option applies only to vehicles previously equipped with fuel injection. If not equipped, fuel tank modifications are required for routing the return line through the sending unit plate back into the tank. The first two methods require welding and should be done by a professional radiator or fuel system repair shop.

Rubber Return Line Method

Drill a 5/16-inch hole in the sending unit plate adjacent to the main line entry. Insert a short length of 5/16-inch hard line (available at most radiator shops) into the hole and weld it to the sending unit plate. The hard line should extend 1 to 2 inches on each side of the plate. Connect a length (at least 4 inches) of 5/16-inch rubber return line hose to the hard line that extends into the tank. Connect the rubber line to the fuel pickup line using tie wraps.

Bulkhead Fitting Method

Drill a 9/16-inch hole in the sending unit plate adjacent to the main line entry. Insert a #6 AN bulkhead fitting (available at most radiator shops) into the hole, with the narrow end on the inside of the plate. Apply a rubber washer or RTV sealant and fasten the fitting with the nut. Connect a length (at least 4 inches) of flexible return line (rubber or braided hose) to the fitting end. Connect the return line to the fuel pickup line using tie wraps.

Note: This method requires no welding of the fuel system.

Hard Return Line Method

Drill a 5/16-inch hole in the sending unit plate adjacent to the main line entry. Insert a length of 5/16-inch hard line (available at most radiator shops) into the hole and weld it to the sending unit plate. The hard line should extend 1 to 2 inches on the outside of the plate. On the inside of the plate, the hard line should follow the contours of the fuel pickup line. Bend the end of the return line away from the sock on the end of the fuel pickup line. Solder or weld the return hard line to the fuel pickup line.

Note: Whichever method you use to install the return fuel line, keep the end of the line away from the fuel pickup to prevent aerated return fuel from being drawn into the pickup.

Fuel System Installation

Note: ALL WELDING AND SOLDERING OF THE FUEL SYSTEM MUST BE PERFORMED BY A PROFESSIONAL RADIATOR OR FUEL SYSTEM REPAIR SHOP.

1. Drain the fuel tank.
2. Remove all fuel lines from the tank and carburetor.
3. Remove the fuel tank.
4. Note: Clean the fuel tank professionally to remove rust or dirt that may damage injectors.
5. Remove the sending unit from the fuel tank. Refer to the RETURN FUEL LINE methods for installing the bypass fuel return line.
6. Install the provided 3/8-inch primary fuel line directly above the original line, which may now serve as a return line. Use large radius bends. Avoid the exhaust pipe and sharp edges.
7. Note: The 3/8-inch high pressure fuel line supplied with the Pro-Flo system must be used as the primary fuel line.
8. If the original fuel line is not used as the return line, route the return line directly alongside the provided 3/8-inch primary fuel line.
9. Mount the fuel pump between the tank and the fuel filter as low and as close to the fuel tank as possible. The pump is directional. Electrical connectors should face the front of the vehicle. The fuel pump must be at or below the level of fuel in the tank.
10. Mount the fuel filter between the fuel pump and the engine.
11. Re-install the modified sending unit plate to the clean fuel tank.
12. Reinstall the fuel tank.
13. Attach the primary line and return line to the sending unit plate on the tank.
14. Re-attach all other fuel lines at the tank (vapor purge lines, etc.).
15. Secure the primary and return fuel lines with the provided tie-wraps, or with Adel clamps if available.
16. Re-attach all fuel lines to the induction system once it has been installed.

O2 Sensor Installation

The exhaust gas oxygen content is determined by the oxygen sensor. The sensor signals the ECU, which compensates for rich or lean air/fuel mixtures.

Note: O2 sensor installation is recommended to be performed by a professional muffler shop.

1. Double check header gaskets, replacing if necessary.
2. Drill a 1/2-inch to 9/16-inch hole in the passenger-side header collector reducer, as close to the header flange as possible (1" to 3" away).
3. Note: Ensure the O2 sensor will be mounted horizontally and within reach of the harness connector, considering engine movement.
4. Fit the provided fitting into the hole in the exhaust pipe and weld into place.
5. After welding, clean the threads in the center of the fitting. If exhaust is coated, tap bung threads to ensure a good ground for the O2 sensor.
6. Thread the O2 sensor into the fitting. A high-heat anti-seize compound has been applied to the sensor threads.
7. Note: The O2 sensor has 18mm x 1.25 spark plug threads.
8. Attach the O2 sensor to the main system harness Connector J21. Refer to the MAIN SYSTEM HARNESS section.
9. Note: UNLEADED FUEL MUST BE USED ONCE THE O2 SENSOR HAS BEEN INSTALLED.
10. Coated Headers: Use a digital OHM meter to measure resistance between the cylinder head bolt and the installed O2 sensor body. The reading should be less than 2 OHMS. If it is more, provide a ground to the O2 sensor mount.

Main System Harness

The Main System Harness is the central nervous system of the Pro-Flo system. Constructed with SAE grade wires and up-to-date Weatherpak connectors, it is a generic harness usable with any application for which the Pro-Flo system is designed. This diagram illustrates the entire Pro-Flo Main System Harness.

Connectors

The "J" coding is for illustration purposes only. The connector ends DO NOT have a "J" code stamped on them.

• J1 ECU
• J2 Calibration module
• J3 Pump harness
• J8 Throttle Position Sensor
• J9 Manifold Absolute Pressure sensor
• J10 Coolant Temperature sensor
• J11 Manifold Air Temperature sensor
• J12 Distributor
• J13 Injector, number 1 cylinder
• J14 Injector, number 3 cylinder
• J15 Injector, number 5 cylinder
• J16 Injector, number 7 cylinder
• J17 Injector, number 2 cylinder
• J18 Injector, number 4 cylinder
• J19 Injector, number 6 cylinder
• J20 Injector, number 8 cylinder
• J21 Oxygen sensor
• J22 Connector to IAC
• J23 Relay
• J24 ECU fuse
• J25 Pump fuse
• J26 Ignition amplifier
• J27 IAC connector
• P27 IAC connector to main harness
• RT1 Engine ground
• RT3 Starter

Installation

1. Inspect the Main System Harness, ensuring all connectors and grounds are properly in place.
2. Drill a hole in the firewall on the passenger side. Cut two overlapping 1 1/4-inch holes on a 1-inch center in the firewall. Saw the pointed edges to create an oval-shaped hole.
3. Note: An alternative is to cut a single 1 3/4 inch hole.
4. Extend the fuel pump relay, ECU connector, and Calibration Module relay through the firewall hole into the passenger compartment.
5. Note: T-connectors at the joints of the Main System Harness are closed by snap fasteners. Open them by hand or with a flathead screwdriver. Once open, T-connectors can be rotated for ease of installation.
6. The 3 1/2 x 2 1/4-inch aluminum plate included on the harness mounts over the firewall hole using four hex head sheet metal screws.
7. Note: Start screw holes with a pointed punch or small drill.
8. The wire harness is assembled with the aluminum plate flush against a T-connector. Cut the black plastic casing on the wire harness to allow the plate to slide up the harness to the correct location. Reattach the casing on both sides of the firewall.
9. CAUTION: When feeding the wire harness through the firewall, be careful not to damage wires against the cut sheet metal.
10. A rubber grommet is provided to protect the wires in the aluminum plate. Use RTV to seal the plate to the firewall.
11. Install all connectors according to the list and diagrams. Each connector is unique and fits only its correct match.

Harness Connections

A. IAC Wiring Harness: This 5-inch harness connects the Idle Air Control, mounted on the air valve, to Connector J3 on the Main System Harness.

B. Ignition Amplifier Wiring Harness: This 3-foot harness connects the distributor cap to the ignition amplifier. The ground connects to the rear of the cylinder head. When used with a small cap distributor or any distributor with an external ignition coil, this harness must be slightly modified. The three wire leads at the distributor connector must be cut from the connector (or released with a small screwdriver) and individually routed using the provided terminals. The black wire may be removed between the connection and the 3/8" ring lug. The 3/8" ring lug must still be grounded on the rear of cylinder head. The red and brown wires are routed as follows:

• RED: ignition coil positive (+) terminal +12 start/run.
• BROWN: ignition coil negative (-) terminal. Sleeves and tie-wraps are provided to fit over the terminals.

C. Fuel Pump Wiring Harness: The connector on the left end of this 10-foot harness attaches to connector J3 on the Main System Harness. The two connectors on the right connect to the positive (+) and negative (-) terminals on the fuel pump. A sleeve and tie-wrap are provided to fit over the positive terminal to prevent the clamp from shorting the fuel pump terminals.

A KEY ON wire (Pink with black stripe) is also included. This wire connects to the fuse box. Ensure power with the key on and while cranking.

Refer to VEHICLE REPAIR MANUAL FOR WIRING DIAGRAM, IF NECESSARY.

Electronic Control Unit /System ECU: The ECU must be mounted away from moisture, excessive heat, or vibration. Recommended locations are underneath the dashboard on the passenger side, or behind the glove box, not in the engine compartment.

Induction System

The Edelbrock Pro-Flo system delivers fuel and air to the engine via the induction system, consisting primarily of a manifold, 4-barrel air valve, fuel rails, and fuel injectors. The system is fully assembled, tested, seal checked, and flowed at the factory. DO NOT DISASSEMBLE any of these components during installation.

Fuel Rails

The extruded aluminum rail assembly routes high-pressure fuel to the injectors. Aluminum rails offer advantages over soft rails in style and safety.

Intake Manifold

The Edelbrock manifold used with the Pro-Flo system is similar to the Victor Jr. high-performance single-plane manifold, designed specifically for electronic fuel injection applications.

2-Barrel Air Valve

The #3503 Pro-Flo system uses a 2-valve throttle body, flowing up to 750 cfm at 1.5" of mercury when wide open.

4-Barrel Air Valve

The Pro-Flo system uses a progressive linkage valve body with four throttles in a conventional 4-barrel pattern, with staged secondaries, flowing up to 1000 cfm at 1.5" of mercury when wide open.

Fuel Injectors

The Pro-Flo #3500 system uses high impedance pintle-type fuel injectors flowing 28 lbs./hr. at 50 psi. They mount directly onto the manifold, one at each port. The #3503 and #3507 use Magneti-Marelli Pico injectors flowing 29 lbs./hr. at 42-45 psi.

Pre-Installation

Before installing the induction system, follow these steps for successful installation and performance:

1. Check all components thoroughly for damage.
2. Ensure all throttle linkages open entirely and close freely.
3. Ensure all fuel inlet and vacuum ports are free from packing material.
4. Check the installation kit for proper parts.

Removing the Stock Carburetor and Manifold

1. Disconnect battery.
2. Keep all parts in order for ease of installation.
3. CAUTION: Do not remove manifold if engine is hot.
4. Drain radiator coolant (drain plug typically on lower right facing engine).
5. Remove gas cap to relieve pressure. Disconnect fuel line and plug. Replace gas cap.
6. Disconnect all linkage from carburetor (throttle, throttle springs, transmission, cruise control, automatic choke).
7. Tag and remove coil wires and sensor wires.
8. Remove previously marked vacuum lines.
9. Remove radiator hose, thermostat housing, and thermostat (if mounted on manifold).
10. Remove all brackets from the manifold.
11. Loosen or remove valve cover bolts for manifold removal and replacement. Replace valve cover gaskets if broken to prevent oil leakage.

Port Surface Cleaning

When cleaning old gaskets from head surfaces, lay rags in the lifter valley and stuff paper into the ports to prevent gasket pieces from falling into ports and combustion chambers. Remove paper, ensuring all particles fall on rags. Remove rags, and wipe surfaces clean with rags soaked in lacquer thinner to remove oil or grease. This procedure is necessary for proper sealing.

Installing Fittings, Pipe Plugs, and Studs

Do not over-tighten or cross-thread fittings, pipe plugs, studs, or bolts in your aluminum manifold. Damage to threads or a cracked mounting boss may result. Use caution when installing accessories.

Use high-quality pipe thread sealant on all threads. Install fittings from your stock manifold.

Gasket Surface Preparation

CAUTION: Replace all gaskets as recommended. Do not use race-type non-embossed gaskets for street applications. Material deterioration under street driving conditions may cause internal vacuum and oil leaks. Edelbrock recommends Fel-Pro Printoseal gaskets #1205 or equivalent. Do not use Fel-Pro Permatorque Blue gaskets, designed for stock cast iron intake manifolds only.

1. Check gaskets on head surface and manifold to ensure they are correct. Embossed side faces up.
2. Note: Some cases may have different right and left side gaskets. Ensure correct placement.
3. Coat head surface and both sides of gaskets with Edelbrock Gasgacinch #9300.
4. Apply Loctite 598 OEM High Temperature Silicone Gasket around water passages on the head surface.
5. Gaskets and surfaces will become tacky within minutes. Carefully place gaskets on head surface, aligning ports and bolt holes.
6. Edelbrock recommends Loctite 598 OEM High Temperature Silicone Gasket instead of end seal gaskets. Apply a 1/4-inch thick bead of sealant across each end seal surface, overlapping the intake gasket at the four corners.
7. Note: Use recommended silicon sealer. Others may damage the O2 sensor. This method eliminates end seal slippage and deterioration. Use Edelbrock Manifold Bolt and Washer Kit #8504 for ease of installation.
8. Apply Edelbrock Gasgacinch #9300 to the manifold port surface and head surfaces for a good seal.
9. Apply RTV gasket sealer around water passages on the manifold.
10. Surfaces will become tacky within minutes.

Induction System Installation

1. Carefully position manifold and air valve on engine, centering bolt holes with the bolt holes in the head.
2. Apply thread sealer or Teflon tape to exposed bolt threads.
3. Hand tighten all bolts.
4. Torque all manifold bolts: #3500/3503 use 25 ft/lbs; #3507 use 11 ft/lbs. Torque in the sequence illustrated.
5. Re-connect throttle linkage, springs, transmission, cruise control, and fuel lines. Check all linkage for smooth throttle operation from idle to Wide Open Throttle.
6. Note: Do not install with a throttle rod; use a cable actuated throttle.
7. Re-tighten the valve cover bolts.

Other Applications

The Pro-Flo system is designed and calibrated for Chevrolet 350 c.i.d. small-block engines with large-valve style cylinder heads (e.g., Edelbrock's Performer RPM Street Cylinder Heads with 2.02-inch valves) and tubular headers. If your engine differs, correct chip matching your cam profile and necessary fuel calibration adjustments are required. Refer to the SYSTEM SET-UP SECTION of the Owner's Manual for details.

Small-block Chevrolet Displacement and Fuel Calibrations:

Note: These are approximations; results may vary. Calibration points can be adjusted as necessary.

If running small-valve heads or not using tubular headers, adjust the air/fuel ratio at WOT from 4000 rpm and up. Refer to the FUEL @ WOT screens (under FUEL MODIFIERS) for adjustments.

It should not be necessary to lean fuel calibrations at 12" or 18" vacuum.

WARNING: Watch the Rich/Lean light on the Calibration Module. If it indicates a lean condition (red) for more than a fraction of a second at 06" vacuum or WOT, you are too lean for safe engine operation at full load.

System Start-Up

After installing the Edelbrock Pro-Flo system, follow these break-in procedures for best results and optimal performance.

Pre-Start Checklist:

• Has the battery been reconnected?
• Has the radiator been refilled with coolant?
• Has the gas tank been refilled?
• Has the oil been replaced?
• Have all linkages been reconnected?
• Have all wiring harness connectors been connected?
• Have all fuel lines been reconnected?
• Has the exhaust system been completely re-installed?
• Has the O2 sensor been installed and connected?

Distributor Test

1. Prior to installing the modified distributor, connect the 3-pin (black, purple, and red wires) distributor connector to the wire harness (J12).
2. Unplug (J3), the fuel pump connector, to prevent operation during this test.
3. Do not apply power from the ignition coil.
4. With the key ON (Start-Run Power), rotate the distributor by hand. The Calibration Module should show RPM values greater than zero.

Installing the Distributor

1. Rotate the crank until #1 cylinder is coming up on compression.
2. Stop turning when the crank is 10 degrees BTDC.
3. Rotate the distributor shaft until the rotor points to #1 cylinder in the Distributor Cap.
4. Insert the distributor into the engine.
5. Note: You may need to repeat this cycle to ensure the oil pump drive is engaged.
6. Rotate the distributor body until the leading edge of the small tooth on the shutter wheel is halfway through the hall effect sensor. See distributor picture.
7. Secure the distributor hold-down clamp.
8. Install the distributor cap and connect start-run power to the ignition coil.

Priming The Fuel Pump

Before starting the engine, prime the fuel pump to pressurize the system and purge air from the fuel line.

1. Turn ignition key to the ON position. You should hear the fuel pump run for 2 or 3 seconds and then disengage.
2. Turn the key to the OFF position for 1 second.
3. Turn the key to the ON position again. The pump will run for another 2 or 3 seconds.
4. Repeat this procedure three or four times until the pump is primed. The tone of the fuel pump will change when all air is out of the fuel system.
5. If there is no tone or change in tone, the system is not priming. Check the entire fuel system for leaks, from the fuel tank to the injectors.

Testing The Sensors

Before starting the engine, test all sensors.

1. Turn the key to the ON position with the Calibration Module connected. The display will read: RPM: 0 FUEL: 0.0 mS, VAC: 0.0" Hg, SPK: 10°.
2. Note: Vacuum reading may vary depending on barometric pressure and air temperature. At extreme altitude, vacuum may be as high as 5.0" Hg.
3. Push the UP ARROW key once to display: TH20: 76°F, TAIR: 77°F, TPS: 13°, Volt: 12.0.
4. Note: Water and air temperatures vary with ambient conditions. System voltage varies with battery condition.
5. Move the throttle to test the Throttle Position Sensor (TPS). The TPS reading should vary with throttle angle.
6. If the Calibration Module displays error messages, refer to the TROUBLESHOOTING section of this manual and the User's Manual.
7. Note: If the calibration module goes blank while cranking, the system is losing power. Check the Pink/Black wire attached to the 3 Amp fuse for +12V power with the ignition in the crank and run positions.

Starting The Engine

After the fuel pump has been primed and the engine started, bring the engine speed up to cam break-in RPM (hold throttle at 2000 to 2500 RPM for 10 to 20 minutes), following the cam break-in procedure described in the CAMSHAFT section.

Timing Adjustment

Use a timing light to re-time your engine after the induction system and distributor have been installed and re-installed. Refer to the INDUCTION SYSTEM and IGNITION SYSTEM sections.

1. Remove spark plug from Number One cylinder.
2. Remove coil wire from distributor and ground it.
3. Note: This step requires two people or a remote starter switch. One person rotates the engine by bumping the starter, while the other holds a finger over the Number One plug hole until compression is felt.
4. Continue to bump starter until the timing mark on the crankshaft pulley shows approximately 10 degrees Before Top Dead Center.
5. Position the rotor to align with the Number One cylinder plug wire terminal in the distributor cap. Check that the leading edge of the narrow tooth on the shutter wheel is centered in the sensor when the shutter wheel rotates clockwise. Refer to the IGNITION SYSTEM section.

Setting Base Spark Advance

After camshaft break-in, re-set the engine's base timing. Use a timing light and the Pro-Flo Calibration Module.

1. Start the engine.
2. The Calibration Module screen will display: RPM: 0 FUEL: 0.0 ms, VAC: 0.0"Hg, SPK: 10°.
3. Press the DOWN ARROW key to reach: <MISC. MODIFIERS> ENTER to select.
4. Press ENTER to display: Target Idle RPM:xxxx.
5. Press the UP ARROW key six times until the module displays: Base Tim'g set: OFF, EXIT = SCROLL ENTER.
6. Press ENTER. Press either ARROW key; the screen will display Base Tim'g set: ON.
7. Set base timing using a timing light with the engine running at 1500rpm. Turn the distributor until 10° advance is set.
8. Press the UP ARROW or DOWN ARROW key to turn Base Tim'g set to OFF.
9. WARNING: DO NOT DRIVE THE VEHICLE WITH BASE TIM'G SET ON. SERIOUS ENGINE DAMAGE MAY RESULT.
10. Note: If using an advance-type timing light, the degrees advance shown on the Calibration Module (SPRK:) should agree with the actual reading at the crank with the timing light.
11. Press the EXIT key. You can now leave this screen using the UP ARROW or DOWN ARROW keys.

Idle Adjustment

This procedure is a general recommendation to help tune your Pro-Flo® system.

Note: In manual transmission cars, follow this procedure with the car in Neutral and the clutch pedal pressed. In automatic transmission cars, follow with the car in park/neutral and the brake pedal pressed.

Idle Calibration Procedure

• Prior to idle calibration, complete the "System Start-Up" procedure.
• Warm up engine to at least 175°F.

Idle Control

• Using the calibration module, Select MISC. MODIFIERS and Set Idle Control OFF.

Set Idle Mechanical Stop

• Set the mechanical stop screw so that idle speed in park/neutral is 50-100 RPM higher than the desired idle speed in gear with idle control on. Typically 600 - 1000 RPM depending on the installed cam shaft.
• 650 RPM is a good idle for the #3512 performer calibration.

Set Throttle Position Sensor

• Loosen the two Throttle Position Sensor (TPS) mounting screws, and rotate the TPS sensor to a setting of 13 degrees as observed on the Calibration Module.

Set Idle Fuel Modifier and Idle Spark Modifier

• Using the calibration module, Select MISC. MODIFIERS and adjust Idle Spark and Fuel Modifiers to obtain best idle quality. Idle quality will vary with engine design. Fuel and Spark settings interact, particularly when approaching best settings.
• Establish a smooth idle before using Idle Control, otherwise RPM will surge when Idle Control is turned on.

Save Calibration

• Re-check that the TPS setting is 13 Degrees.
• Using the calibration module, Select MISC. MODIFIERS.
• Set IDLE CONTROL ON. Set TARGET IDLE to the same RPM established by the idle stop screw.
• Save calibration settings to “A”.

Idle Speed Activity

• Displayed on the calibration module (Second Data Screen). The value represents the amount of air bypassing the throttle blades of the air valve. Normal values range from 5% to 75%. This ensures the computer can increase or decrease idle air flow to control idle speed.
• If a "good" idle setup is established, RPM will remain nearly constant between in-gear and out-of-gear. Idle Speed Activity will change 10-30% as it adjusts idle speed.
• Idle Activity is 20% when Idle Speed Control is off.

Idle Speed Activity Modifier

• This function is locked out when Idle Control is off (indicated by "XXXX" in the Target idle display).
• The Idle Speed Activity Modifier biases the Idle Activity duty cycle (+/-50%), affecting RPM control loop response time.
• Set to zero modification except in extreme cases.

Part Numbers

Many Pro-Flo system components are available separately. Some are standard OEM parts. Replacements can be found at your local parts supplier, Edelbrock dealer, or directly from Edelbrock.

Edelbrock Pro-Flo

• Fuel Injection System: Edelbrock #3500
• Ignition Amplifier: Edelbrock #3518
• ECU power relay/Fuel pump relay: Edelbrock #3586
• Manifold Absolute Pressure sensor: Edelbrock #3587
• Manifold Air Temperature sensor (Screw-In): GM 16006835
• Manifold Air Temperature sensor (Push-In): Edelbrock #3588
• Coolant Temperature sensor: GM 25036751
• Throttle Position sensor: Edelbrock #3589
• Oxygen (O2) sensor: Edelbrock #3590
• High pressure fuel pump: Edelbrock #3591
• Fuel filter: Edelbrock #3594
• Fuel pressure regulator: GM 25055065
• Fuel injectors (set of eight): Edelbrock #3597
• #3500 Kit use: Edelbrock #3598
• #3503/#3507 Kits use: Edelbrock #3853
• Fuel injectors (one): Edelbrock #3585
• #3500 Kit use: Edelbrock #3585
• #3503/#3507 Kits use: Edelbrock #3583
• Hall Effect Sensor: Edelbrock #3517
• Calibration Module: Edelbrock #3519
• Calibration Module Cord/Plug: Edelbrock #3571
• Idle air control solenoid: Edelbrock #3599
• Ford FOAE-9F715 B1A
• Throttle Cable Bracket #3500 or #3503: Edelbrock #8031
• Throttle Cable Bracket #3507: Edelbrock #8032

Complete Pro-Flo System Parts

• (1) Hall effect sensor
• (1) Ignition Amplifier
• (1) Manifold Absolute Pressure sensor
• (1) Manifold Air Temperature sensor
• (1) Coolant Temperature sensor
• (1) Throttle Position sensor
• (1) Oxygen (02) sensor
• (1) High pressure fuel pump
• (1) Fuel filter
• (1) Fuel pressure regulator
• (1) Fuel injectors
• (1) Idle Air Control solenoid
• (1) Main system harness
• (1) Fuel pump wire harness
• (1) Shutter wheel spacer
• (12) Fuel line tie wraps
• (1) Fuel pump relay
• (1) 3 amp fuse
• (1) 20 amp fuse
• (1) 5-inch cross tube
• (1) 2-inch cross tube
• (1) Intake manifold
• (1) Shutter wheel
• (1) MAP Sensor bracket
• (2) Fuel rail
• (1) Return line O-ring tube
• (1) Throttle body air valve
• (4) Cross tube clamp
• (1) Mechanical advance lockout plate
• (8) Fuel filter clamp
• (1) 5/16-inch hose to 1/4-inch pipe fitting
• (1) 1/8-inch pipe to 1/4-inch hose fitting
• (1) 1/4-inch pipe to 3/8-inch hose fitting
• (1) Regulator/rail adapter
• (1) Return line adapter
• (2) 3/16-inch washer
• (1) Air valve/manifold gasket
• (8) 3/8-inch fuel line
• (15) 11/32-inch PCV hose
• (8) 5/16-inch rubber fuel line
• (1) Pressure regulator shim
• (2) Shutter wheel shims
• (2) 10-32 nut
• (4) 5/16 24 hex nut
• (1) Wiring harness cover plate
• (2) #10 internal star lock washer
• (2) 1/4-inch pipe plug hex c/s dryseal
• (2) 5mm x 25 hex head cap screw
• (4) 5mm x 10 hex head cap screw
• (1) 8-32 x 0.25 allen head screw
• (2) 10-32 x 0.75 round head m/s screw
• (1) 5mm x 0.8 x 30mm hex head m/s screw
• (2) 10-32 x 1.50 Fillister head screw
• (4) 5/16-18 x 1 socket head cap screw
• (1) PCV valve
• (1) Std. 1/4-inch Schrader valve
• (5) Cross tube O-ring
• (1) Regulator adapter tube
• (4) 5/16-inch star washer internal
• (2) O-ring
• (4) 5/16 x 1/2 carb stud

Service

If your Edelbrock Pro-Flo System needs servicing, return the unit pre-paid to the Edelbrock Service and Repair facility at 2700 California Street, Torrance, CA 90503. Do not attempt to disassemble or service the components yourself, as this may void the warranty.

Warranty

Edelbrock Corp. warrants the Edelbrock Pro-Flo System to be free from defects in workmanship and materials for one year from the date of purchase, provided it is properly installed and subjected to normal use and service, not used for racing or competition, and not modified or altered unless specified by instructions. Warranty service and repair is at 2700 California Street, Torrance, CA 90503. Customers requiring warranty assistance should contact the dealer from whom they purchased the product. The dealer will contact Edelbrock to determine warranty satisfaction. If the product must be returned, include proof of purchase and a clear description of the problem. Return freight must be pre-paid. If factory inspection indicates defects, Edelbrock's sole obligation is to repair or replace the product. This warranty covers only the product itself, not the cost of installation or removal.

EDELBROCK CORP. SHALL NOT BE LIABLE FOR ANY AND ALL CONSEQUENTIAL DAMAGES OCCASIONED BY THE BREACH OF ANY WRITTEN OR IMPLIED WARRANTY PERTAINING TO THIS SALE, IN EXCESS OF THE PURCHASE PRICE OF THE PRODUCT SOLD.

For questions regarding this product or installation, contact the Technical Department from 8:00am-12:30pm and 1:30-5:00pm, Pacific Standard Time, Monday through Friday.

Tech Telephone: (800) 416-8628

Office Telephone: (310) 781-2222

Fax: (310) 320-3964

Edelbrock Corporation
2700 California Street
Torrance, CA 90503