Brown EFI Installation Guide
For the Chevrolet Corvair
Red is a safety/danger warning
Blue is for really important that will save you time if followed
Italicized is for description
Use of generators is discouraged as the alternator provides cleaner, less noise, and steadier power for the EFI system. If you plan to use a generator, it is highly recommended to install a power conditioner (capacitor box) inline to minimize the power spikes. One wire alternators (Converted LM) are easily obtainable and at swap meets and other Corvair members/vendors. Early model swaps will require a new Delcotron and Alternator. On late models (1965-1960) cars, the ECM/Relay panel is designed to be mounted at the old external regulator location. Remember to add a diode on the gauge side of the alternator to prevent a”running-on” condition due to feedback through the bulb (Details below).
The Corvair EFI installation is simple if taken in small areas and verify each operation as you install.
Disconnect battery power (Neg cable)
Remove Carb System
Modify Fuel Sending Unit to Accept Internal pump
Drill Hole for Return Line
Install Fuel Pressure Regulator (FPR)
Install Fuel Return Line (FPR to Filler Tube)
Install Timing wheel
Install exhaust bung
Install Injection Fuel Lines
Remove Choke rod on passenger side head
Mount Control Panel w/ECM on the drivers side firewall.
Install Wiring Harness over engine.
Install ETS (Engine Temp Sensor)
Install Carb Spacer and Gaskets
Install Ignition Coil Pack/Distributor
Install Crank Sensor Bracket
Install Crank Sensor (Adjust .30 to .60)
Connect Crank Sensor wire
Connect Main Ground wires and Coil/DIS ground cables
Connect all sensors.
Connect the large ground terminal at the left rear of engine compartment.
Connect a 14 gauge (Red) wire from the harness to your electric fuel pump.
Connect the 14 gauge (Red) wire to a full-time fused 12 Volt Battery
Connect the 16 gauge (orange) wire to the 12V Switch (12V when key is on)
Connect Idle Air Control System (ISC) solenoid
Check with Tuner Studio
Initial Calibration of TPS and Temp Sensors
Check for Leaks
Test start and establish stable idle
Check for Leaks Again
Final Calibration TPS
Log test drive and make notes
Check for Leaks Again
Safety: Have a fire extinguisher or other items handy for your safety when working with fuel. Gasoline is very flammable and can get out of hand very quickly. Minimize the use of rubber hose as it does not resist fire or abrasion. If you are not comfortable doing your fuel line work, you may want to find someone more experienced to help. You may lose your car or even your life…. so think about safety in all aspects of installation, testing, repair and driving.
Remove Carb System: Before removing your old carb system, make sure that your engine is pointed to #1 plug wire position. This will aid in the installation and ensure a quick and easy start after installation. You must remove the Carbs, Fuel Lines, round fuel pump and fuel pump rod. (take the Linkage off also and lay aside as you will reuse these items). Do not remove the inside Carb stud as it needs no adjustment. The outside stud will need 1/2″ removed from the bottom (course threads) to in sure proper fit of the throttle body.
Tank Condition: You must first ask yourself….. and be honest about the condition of your tank. If your tank has rust and garbage, these items will go through the pump and destroy it…. period. If your tank is not in good shape or is suspect, remove tank, have it cleaned or install a new one. Corvair tanks are over 50 years old and most have rust and is recommended that tank is removed and cleaned. This will put your Corvair on the side of the road and one of the last things you want to scrimp on. The 1968/69 and Turbo models have a return line already built in, but is very restrictive due and should not be used.
Fuel Pumps: Before you start, You must decide which method of fuel delivery is right for you. They are 3 fuel system methods:
- Fuel Pump in Tank: (most difficult, but quiet and low failure rate)
- External High Pressure pump: (Pump under passenger floor) Noisier than all others
- External 2 Pumps: One (1) low pressure pump under passenger floor and One (1) high pressure pump behind firewall area (above differential/starter area). This allows the repair or replacement of pumps without removing tank and also has a filter between the low and high pressure pumps for high pressure pump protection.
We highly recommend using an internal in-tank pump due to noise and reliability concerns.
Fuel Pump Internal: Bosch #69225 or equivalent should only be used. A new fuel sock , (Bosch #68001) is also required as any trash entering the pump will destroy it in short order. The sending unit must be modified with a bulkhead connector for the fuel pump and ground and can be accomplished with instructions from some Corvair websites for electric fuel pump conversion. This bulkhead connector from Revolution Electronics is recommended for an easy conversion. You can also fashion your own bulkhead connector using “JB” weld, but be sure to use the special wiring designed for for submersion in fuel.
Fuel Sending Unit w/Pump: First, Insert the fuel bulb and then bend the filter edges inward so the pump can be installed after the bulb. The pump should mount up and and will need the ring attached to secure the sending unit. Remember to install new rubber seal on the tank to sending unit to prevent future leaks.
Return Fuel Line Hole: You will need to drill a 3/4″ hole next to the factory hole for the return fuel line. This support beam is double walled and will require a bit long enough to reach through. Be careful not to drill to far in and damaging the fuel tank.
Fuel Line Return: It is recommended to remove the fuel inlet nozzle *neck”, braze in a 5/16″ steel tube (2″ in length) and attach to the return line. An alternate way would to drill and install grommet with fitting as as it will not require brazing, but the neck must still be removed. Excess fuel will flow from FPR to tank to be recycled through system. Line must be brazed/epoxied in some leak proof way of routing fuel back to tank in a manner that allows for reassembly of the nozzle back into the Corvair fuel door/slot opening. DO NOT PERFORM WHILE ON THE CORVAIR – IT MUST BE REMOVED.
Fuel Pressure Regulator/Filter: This Regulator was chosen for its compactness, GM design, price and its dual function as a filter. This is the slip-on type of connector for the main feed and the “IN” and “RET” lines have been modified to accept rubber fuel line. The feed line from the tank sending unit is connected by high pressure rubber hose and clamp attached to an “S” tube. The “S” tube is then connected to the FPR “IN” nipple by 3/8″ high pressure rubber hose and worm clamp. Return lines are connected by high pressure rubber hose from the FPR “OUT” to the return on the filler tube. Remove the tunnel pan to expose the existing fuel line and cut the line where it will allow enough room to connect the high pressure hose to the line. Use a device (flaring tool) that will install a bubble or bump on the line that will not allow the high pressure hose to back off under pressure. The other end of the 5/16″ line connects at the rear of the engine bay and will be connected to the engine “T” adapter fuel line.
USE ONLY HIGH PRESSURE EFI RUBBER LINE. All others will fail and when they do fail you will have pressured fuel spraying on the exhaust system. This is one of the last things you want to “Cheap out” on as you will lose your car and maybe something more valuable.
Installing Engine Fuel Lines: The fuel lines to the TBIs are 1/4″ steel with double flare ends and connect to our fuel injector adapter. Normal amount of Torque is necessary to install the fuel lines to the Fuel “T” and normally tightened to where they will not leak. ALWAYS use Line wrenches and proper tools to prevent fuel leaks. The lines are pre-bent to accommodate routing, but can be bent slightly for ease of installation or customer preference. Fuel is under 58 lbs of pressure and leaks can ruin you day, so always think safety when working around fuel.
Engine Temp Sensor: This is a thermistor type sensor that screwed into the shroud bolt location at #4 plug wire. Install this sensor before installing the TBI to permit routing and tighten to 15ft lbs. Route wires so they will not interfere with throttle body or TPS operation. This sensor can be removed and installed with the TBI in place, but will require a higher level of attention not to break or twist the wires.
Install the Throttle Body Units: Use gaskets for a good seal along with the insulator on both sides as the linkage will “bottom out” on engine tins if the insulator is not installed. You should install the thin gaskets (not thick) along with the insulator as the thickness of these are pre-engineered on the Corvair for linkage height.
The TBI will be installed as a unit already assembled and the outside stud will be “shortened” by 1/2″ (course side) and not interfere with the installation of the TBI. If the stud is too high, it will hit the bottom of the injector bung. The outside nut will have to be started on the stud as the TBI is installed.
The TPS has a factory setting of 10%-20% TPS to allow for linkage adjustments, etc. and should not be software calibrated until completely installed. If you have to remove the injector for any reason, during reassembly be very careful NOT to over tighten the hold down screws as it will cause the injector to malfunction. Later designs (May 2019) have sleeves that will prevent over-tightening of the injector and aid in proper alignment. DO NOT ADJUST THE TPS set screw unless instructed by Tech support.
Install Fuel Pump Block-off: The Fuel pump block-off is installed by tapping into place. The factory hold down bolt should not be used unless it is shortened. This bolt or another 3/8″ hex head will also be used to secure the Pickup Sensor Bracket.
Remove, Modify and Replace Distributor: Rotate the distributor to the #1 plug wire position, once in the #1 firing position, do not move the engine until the distributor has been modified and reinstalled. **This future Youtube video will describe the procedure in detail** The guts of the distributor will be removed and the rotor cam will be locked to the shaft to prevent movement. The only part that will need to be reinstalled will be the rotor button. Insure the rotor button is in good shape and is firmly mounted. Move the engine to 20-24 degrees BTDC (see pic) by placing tape on the harmonic balancer. Rotate the distributor to set to #1 position and lock down the distributor using a 9/16″ wrench. Once this setting has been completed, remove the tape and DO NOT MOVE the distributor!!!. Moving the distributor will NOT change the timing of the engine. Moving the distributor will burn the cap and cause premature failure of the cap/wires/plugs.
Mount Control Panel and Wiring Harness: The Control Panel is mounted in the old external regulator location for late model cars (1965-1969). You will need to remove the components to mount the control panel. Early models can be mounted in the same general location and self tapping screws
work the best. After the control panel is mounted, attached the ECM, Relays, and MAP sensor as shown in photo. The ECM is water resistant, but not waterproof and care should be used to keep water directly away from the ECM. All connectors are weather pack or water tight, but care should always be used with liquids and electronic components. The Fuel pump connector is a spade terminal and needs a wire ran to the pump(s) and is not included in the harness. Black heat shrink tubes are included in kit to seal spade and bullet terminals and will seal after heated (do not use open flame). They should only be installed after installation and testing has been completed as they will need to be removed to open connection. On FC/Vans, the ECM will be mounted mounted directly on the firewall along with relays and MAP sensor. You may modify your location and route, but cutting the wiring harness violates your warranty
Connect Map Sensor: The MAP sensor is mounted on the Control Panel and push green weather-pak connector until fully seated.
Trigger Wheel: The Trigger wheel bolts to the front of the Harmonic Balancer using 3/8″ bolts with a spacer between the HB and the trigger wheel. You can install the trigger wheel first then install the HB with the trigger wheel attached. If your HB is already installed on your engine, you can attached the trigger wheel without removing the HB. It is usually best to put the bolts, and spacers on the trigger wheel as to be installed and use light glue or heavy grease to hold the spacers in place until the bolts are tightened. The crank pulley used on early model and low HP models are attached to the provided bolt holes, but the spacers are not required. The trigger wheel is mounted with the engine at 0 degrees and the open slot at approx 10 o’clock position (to the left of the degree indicator). Trigger wheels will have “wrong way” printed on the back (side facing engine), so you should not see those words when installed properly. Spacers are 5/16 nuts drilled out to 3/8″ which provide the perfect distance.
Install Pickup Sensor Bracket: The sensor bracket is mounted to the existing bolt hole for the Corvair fuel pump hold down. It should be mounted reasonably level and may be bent slightly for correct alignment. A/C versions of this trigger wheel need to be mounted to the outer ring of the harmonic balancer and will require you to send us your Harmonic Balancer for modification.
Pickup Sensor: The Pickup sensor is mounted into the Pickup Sensor Bracket from the top and should bottom out in the center of the trigger wheel. You may need to bend the bracket to perfect the alignment. Install with a 1 to 2 credit card thickness (.20-.40) and lock down with the set screw in the side of the bracket. DO NOT OVER-TIGHTEN as it will crack the sensor and must be replaced.
Connect Throttle Position Sensor: The TPS is located on the front of the driver’s side TBIU (not mounted) and is connected with a weather-pak 3 conductor connector.
Connect Injector Electrical Connectors: The injector connectors are the GM LS type and are push and click to connect. They have a clip on the side to disconnect
Connect Idle Control Solenoid: The idle control solenoid is mounted on the passenger side TBI.
Test for Fuel leaks: You can bypass the fuel feed to pump wire directly to the battery or other 12V ground source and check for leaks. The Fuel Pressure Regulator will direct fuel back to maintain the proper fuel pressure. Have a fire extinguisher and a friend handy for this test. Having a leak free system fuel system is very important for operation and your safety.
Connect Fuel Pump Feed Wire: The very last item to connect to prevent accidental fuel spillage and fire danger during testing or accidental activation of the ECM.
Alternator In-Line Diode: Installing the Diode will prevent a “continue to run” situation after the ignition is turned off. This is caused by the ALT lamp in your dash which has just enough resistance to keep the relay open, in-turn keeping 12V to the engine through the #1 relay. For detailed instructions, click here ALTERNATOR DIODE
Idle Air Control Valve (Jan-Aug 19): The IAC valve assembly is placed inline by cutting the PVC hose and inserting the 3/8″ Tee at this cut. Route a 3/8″ vacuum hose to the IAC valve mounted on the passenger side TBI.
Idle Control System (Sep 19-Present): The Brown Idle Control System (ICS) is used to maintain idle control on all models. Insert the 3/8″x 1/4″ Tee into the PVC line and run a 1/4″ vacuum line to the idle control solenoid. The idle control solenoid is mounted on the passenger side TBI and is pull side is already connected to the idle control actuator. You will need to connect the 1/4″ tube between the solenoid and the “Tee” in the PVC line. The ICS uses the Corvair choke pull-off and GM EGR solenoid for simplicity and ease of replacement.
Connect Laptop w/Cable: Connect the cable to the USB port of your laptop. It may have to load a driver and take a few minutes the first time it is connected. Download the TunerStudio program which you will use to access the ECU with your laptop. After installing, open the program. You will need to determine which comm port your USB cable has selected and change the TunerStudio to match that comm port. The ECU must be on (engine not running). After you get communications, read the software and tuning page.
Set Initial Calibration for TPS and Temp: The TPS will need to be calibrated 2 times, this being the first, and again after the manual idle balance and adjustment has been performed.
- To Set TPS (watch this youtube video)
- To Set Engine Temp (watch the youtube video)
You are now ready to start the engine. It is advised that this be a 2 person operation… one to start the engine or turn off in an emergency and another to watch for any issues. The first start should be accomplished outdoors in case of fire, rich running, etc. Have your computer setup with TunerStudio running so that you can quickly identify any issues that may cause the engine not to run or run poorly.
Air Cleaners: Because so many people have different ideas about air cleaners, we leave that to the end user. The TBIs will accept Corvair Factory Air Cleaners (2″ inner bore) but may require modification for “hold downs” that secure the cleaner to the TBI based on the air cleaner used. Early models and FC use the flat type of cleaners and can be modified with 2 holes for the hold down spring. Late model will require 1 hole drilled and modifying a “L” hook as a hold down. The outside diameter of the TBI bore is 2.25″ and any many aftermarket air cleaners will work.
Install Guides for the following ignition options.