Owner’s Manual & Troubleshooting

Owner’s Manual

Corvair EFI System 

Manufactured by Brown Injection Systems, LLC

This Owner’s Manual is designed to explain the basic concepts and the component functions of the EFI system.  You should read this manual and the Installation guide fully before starting your installation.  Both are a work in progress and constantly updated…. so check back often. 

This kit was designed and built with 3 major objectives:
• Increase performance, dependability, and driveability of the Corvair.
• Completely reversible
• Cost-effective

We hope you find this one of the most well-thought-out, economical, and dependable kits ever produced for the Corvair, and should provide years of trouble-free service. This EFI system is a DIY system with many pre-made/adapted parts to aid you in the successful installation of your system, but it relies on your skill and knowledge of Corvairs and EFI. If you doubt your abilities, hire an installer or friend/club member to help you with this installation.  The Gen2 kit is much easier and friendlier than the Gen1 to install and most can install if you have a laptop and voltage meter.  We also offer modification of your sending unit with a fuel pump and fuel line return adapter to simplify your installation.

Advantages of EFI over Carbs and Points:  There are many maintenance advantages of EFI w/electronic ignition over carbs and points.  Cylinder wash (large amounts of raw fuel entering the combustion chamber) is all but eliminated with EFI as a flood situation is highly unlikely to a properly installed system. Quickstarts, hot starts, and immediate drivability are all possible with EFI.  Spark plugs fouling is a thing of the past and plug wires will last a lot longer now that constant removal for testing is no longer needed.  During your scheduled oil changes, you will notice cleaner and less diluted oil which extends engine life.  Carb rebuilding and point replacements are a thing of the past as the injectors and ignition components will outlast the engine.

Background: Fuel injection has always been costly for Corvair mainly because port injection requires costly welding and the use of low-production parts. The Throttle body was chosen for its dependability and simplicity and uses mostly GM production parts to keep the price low.    The dual throttle body has been used before but was fragmented and used a costly computer to run.  EFI Temp input was always a problem for Corvairs due to the wild temp fluctuations of the Air-Cooled engine, but we have solved this using our temp sensors.   The First Generation EFI used mostly used GM parts, but as time has passed, these parts (Throttle bodies and ECMs) have become difficult or impossible to locate.  We designed the 2nd Generation of EFI to use mostly off-the-shelf or manufactured items so the supply of parts will not end.  The 2nd Gen also uses more Corvair-specific parts to reduce cost and allow the use of factory linkage and air cleaners.

Theory: Carbs and points that control the conventional Corvair and all engines of that era are a compromise. The Carbs give the best fuel mixture only under certain loads and airflow due to their design. Distributors can’t compensate for Temp and use flying weights to control the timing… good, but again a compromise. Fuel Injection along with electronic timing applies the best fuel mixture and timing for that RPM, Load, and Temp at all times to provide the best performance.

What should I expect?: Ease of starting, good all-around performance, and better fuel economy.  It does not fix burned valves, leaking heads, cracked pistons, etc…. its fuel injection. It maximizes the amount of fuel and timing for the best all-around performance and economy based on external factors that a traditional Carb and points can’t do. During the initial cold starting,  the engine will run rich to aid in the cold start and run.  The reduction in cylinder wash (from manual chokes) along with better fuel ratios will extend the life of the engine, plugs, wires, and associated electrical items.  Starters will last longer due to reduced cranking and make the earth a little better place to live due to lowered emissions.

Just because you can does not mean you should: Fuel Injection will allow you to start the engine and drive very soon after starting, even in cold weather. Today’s engines have close tolerances which allow them to run cold without damage. The Corvair engine was never designed to meet designed clearances until after its warm. Yes… you can drive your vehicle immediately after cranking, but it is advisable to do lightly so until the engine has warmed and proper clearances have not been obtained.

What do I need/have to purchase that does not come with the kit:5/16″  Fuel return line (FPR to fuel return)
Misc Bolts/Screws to meet customer desire

I want to tune my car for more performance/fuel economy:  This system can incorporate the use of a Wide Band O2 sensor and is recommended for an upgrade to your EFI.  It is difficult to use Tuner Studio’s Autotune feature without the use of a WBO2 sensor and you may do more harm than good.  Extra care should always be exercised in tuning to avoid running an engine too lean under load.  The Corvair does not like lean conditions even under normal circumstances and will “sputter and spit” when taken too far. The WBO2 sensor, like the Spartan2, is a perfect upgrade for anyone wanting to control their AFR (even the daily driver).

Early Model (EM) vs Late Model (LM): 61-63 EM and low HP 64’s did not come with a Harmonic Balancer (HB). When a harmonic balancer is used, you must also switch the rear engine mount to a 64 model or shim with washers so the belt has sufficient space for a fan belt change.   The timing wheel/harmonic balancer combination will not fit on the FC without shimming the rear bracket.  The EM air cleaners have a hold-down spring and the spring must be trimmed to fit properly.

ECM: Under ECM control, the fuel pump will operate for 5 seconds when the ignition is turned on. It will resume operating when you start to crank the engine and continue running when the engine starts. ECM uses the sensors and programmed info to run the engine at the near-best performance. Normally the engine will go closed loop after 30 seconds of running. With all of the above connections made, your engine should start right up.  The ECM controls the idle based on an RPM table and sensors.  It monitors vacuum (load), Throttle position, temp, and engine speed and commands the injectors to send the proper amount of fuel and timing to the engine.  Those are the basic functions of the ECM, but they will do so much more.  TunerStudio software (free) will open up a world of opportunities to better control your engine.

Control Panel:  The control panel mounts the ECM, both Relays, MAP Sensor, and wiring harness reduce the overall “footprint” of the computer/components and simplify the installation.  Late and Early models have different mounting locations.    You will need to remove components and drill holes in the plate to secure your control plate to your body which will hide these screws.  After the control plate is secured, re-attached the components to the panel.  In late models, it is recommended to drill and secure the control panel to the existing holes from the external regulator which should already be removed. Early models have the control panel mounted horizontally with the wiring harness on the left side of the panel.  The FC models have a special control panel that fits the contour of the engine bay next to the main wiring entrance.   Control Panel Plate needs to be grounded to the body with the screws are and the additional ground will need to be installed.

Engine Temp Sensor: The engine temp sensor is installed at the shroud bolt-hole sensor at the #4 cylinder location.  The engine temp sensor takes the reading from the #4 bolt hole and tells the ECU if the engine is cold, warm, or hot.  It is not designed as a warning system or to indicate the exact engine temp for the user.  It has a snap-to-click connector with a lock to prevent accidental disconnect.  If disconnected, the ECM will default to a fully warm condition to allow continued operation without producing a cold (choke) condition.   If a rich condition does occur after the engine is at normal operating temp and disconnected, the temp sensors need setup and calibration with the TunerStudio software.

Throttle Bodies: 2 or 4 Throttle bodies are supplied and are equipped with modern, off-the-shelf, high “Z” injectors and manufactured for long-term durability.  They are powder coated to prevent rust when built, but other colors or professional powder coating can be applied.  The driver’s side TBI is equipped with a GM TPS that is fully adjustable to prevent binding.  If you ever need to replace the TPS, it will need to be modified before installation.  The passenger side TBI is equipped with the Idle Control System (ICS) to provide good idle, higher idle when cold, and a momentary rise in RPMs during starting.   Injector stand-offs are used to prevent over-tightening of the injector assembly to prevent damaging/crushing the injector.

The first models have the mechanical cold idle advance and are adjusted in the same manner as the Corvair Carburetor except there is no choke butterfly valve.  During cold temps, the Corvair spring pushes the Cam to open the throttle slightly which advances the idle.  When the engine reaches approx 160F, the spring will pull the idle cam where it does not affect the idle.  Later models (Produced after July 2019) use an idle air control (IAC) valve mounted on the passenger side TBI.  A hose is routed from the IAC valve to the 3/8″ Tee” provided in the kit and spliced into the PVC hose.  When the engine is cold, the ECM commands the IAC valve to open which creates an idle leak and in turn, increases the idle.  This will continue until the engine is warm and the ECM turns off the IAC valve.  On Automatic engines, the ECM senses the temp and or low RPM and adjusts the IAC to maintain good operations during cold weather (Choke emulation) or during stops/prolonged idle.  Kits produced starting Sep 2019, use a Corvair Carb choke pull-off and solenoid to control the idle.  This solenoid-controlled pull-off idle control uses a vacuum to control the idle during startup, cold, and when the idle drops below 850 RPMs when warm.  This can be “tweaked” using the Laptop/software to adjust the ECM for your particular engine/weather conditions.

Inlet and Return Line Planning (Lines Not provided): We recommend installing the Fuel Pressure Regulator (FPR) at the front of the Corvair.  Care should be taken to ensure no moving parts come in contact with the lines and allow enough slack for rubber fuel line connection. The rubber hose will allow for movement of the engine so as not to bend/break/vibrate the steel line over time.  Rubber Fuel Lines should be tightened, secured, and located to prevent leaking or damage.  Nipples should be placed on lines if you have the availability to ensure there is no slippage of the hose under pressure.  The FPR has a removable mounting tab and ground for securing the body and also is supplied with quick-release nipples for ease of hose installation and removal.   ALWAYS use proper-sized screw-type clamps on all hoses with EFI-approved hoses and minimize the use of rubber hoses where the steel line makes more sense.

Trigger Wheel The Trigger wheel tells the ECM what speed the engine is rotating and the missing tooth is used to indicate when the engine is at TDC.  It is bolted to the front of the Harmonic Balancer using 3/8″ bolts with spacers between the HB and the trigger wheel.   The trigger wheel is mounted with the engine at 0 degrees and the missing slot at approx 10 o’clock position 50-60 degrees ATDC (to the left of the degree indicator).  The use of loc-tit or other securing methods is recommended to prevent unwanted loosening of the bolts.  The tooth painted with “white-out” is used for initial alignment and can be removed easily when no longer needed.

Pickup/Crank Sensor:   The Pickup sensor senses the tooth as the tooth of the wheel passes and generates a small amount of voltage that the ECM detects and adds to a register that determines the RPM of the engine.  This type of sensor is an AC wave-type sensor (known as VR) and can be tested by a voltage meter as the engine rotates.  This system was designed so that the pickup sensor and bracket do NOT have to be removed or adjusted during normal belt replacement.

Fuel Pump/Tank (General):  Just because it holds fuel does not make it a good tank for EFI.   Unless your tank is new, we recommend using a tank sealer system, like POR-15 that cleans, preps, and seals.  One of the big reasons we don’t sell and/or warranty pumps is due to rust and sediment in unprepared tanks that will eventually ruin the pump.

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.  It is highly recommended to place a bump on the sending unit line so that the fuel hose does not slip off under pressure inside your tank (don’t ask me how we know about this).  Make the pump shorter than the end of the float so that, float first and the pump will fit through the tank opening at the same time.   Fold the Strainer back as it is inserted and it will unfold after inserted.

Fuel Pump External: The Airtex E2000 or equivalent should only be used.  Do not use solenoid/diaphragm type pumps as these are cheaper, but will NOT provide the pressures needed that an HP pump produces.  A new fuel tank is recommended, but if you use your used fuel tank, it should be free of dirt, rust, and particles as these will destroy the pump. You can use the diaphragm-type pump as a suction pump and then the E2000 high-pressure pump.  We do not recommend external pumps due to noise.

Engine Fuel Lines: The fuel lines to the TBIs are 1/4″ steel with double flare ends and connect to our fuel injector adapter.  We use steel in the engine compartment to minimize accidental damage from a belt throw, etc, and does not degrade with heat over time as rubber.   The lines are pre-bent to accommodate routing and can be bent slightly for ease of installation or customer preference.

Fuel Return Return:  A fuel line return is required for this type of installation.  The return sends excess fuel (fuel over 58 lbs) back to the tank and is recycled back through the pump.  If the fuel line becomes blocked, this would create excess pressure and cause the injection system to run outside its designed limits.

Corvair Distributor:  The Factory modified Corvair distributor has all the guts removed and locked down to be an ECM-controlled distributor.  Only the rotor and cap are necessary and all other components can be removed to extend the life of the bearings.  Phase the distributor at 20-24 degrees BTDC on the #1 plug wire and lockdown with a 9/16″ wrench.   Once the phase has been set, no other changes to the distributor should be made.  We recommend placing the coil at the rear of the engine on the cowl support as this will keep the coil cool and out of the way.  It can be placed on the engine as shown but will wick heat from the head and reduce the life of the coil. A special coil wire is provided with the kit that will reach between the coil and the Corvair distributor.

O2 Sensors:  Your O2 sensor senses the amount of oxygen in the exhaust stream and trims the fuel-rich or lean.  A Narrowband O2 (NBO2) only reads a 14.7:1 air-to-fuel ratio (AFR) and works well for most applications, but the ECU cant use an NBO2 Sensor to command the engine to burn at a certain AFR.   If you want to control your AFR for more power or economy, you will need a WBO2 sensor.  Dual O2 sensors (Wide or Narrow Band) can be connected to the system, but a wire will need to be added to the wiring harness.  Using two (2) wideband sensors will allow each head to be individually controlled by the AFR table and WBO2 sensor.  If you want to use a wideband, TunerStudio software has an autotune provision that will auto-adjust the VE Tables to match the AFR table settings.   We highly recommend using a WBO2 sensor for a higher level of engine control.

Wiring Harness: Your wiring harness has been produced using all new parts and all connections have been soldered/shrink or use GM/Packard crimp tools and connectors.  Ends have been marked with stick-on tags to add-in installation.  Relays and relay holders are 30/40 amp 5 pin standard and available at any parts store electrical shelf.  If you remove the relay for testing, etc… pay particular attention when re-inserting the relay not to push the relay connector from the bottom of the connector housing which may cause failure or intermittent failures.

Battery wire: The Red 14 AWG wire must be connected to a fused 12VDC constant battery source.  We include a circuit breaker type of fuse that will allow the system to short and reset.  YOU MUST USE A FUSE to protect your car and your life.

Switched wire: The orange 18 AWG wire marked “switched 12V” should be connected to a switch (12-V with a key on and 0-V with a key off). If you use the existing resistor coil wire, you must tap it very close (within 2″) to the connector to prevent voltage reduction.  You will no longer need the resistor wire and is the preferred method to power the switch wire.  The ECM and relays must have 12V from the switched wire to work properly.

Ground wires:  Three (3) Ground ring terminals are provided in the wiring harness for grounding.  One ground is at the Relay, the main ground to the head, and another ground at the coil.  Grounds are very important to the proper and reliable/consistent operation of the system.  Loose or disconnected grounding will cause intermittent running, shorten the life of the system, and will damage the computer, wiring, and other components.

Idle Control System:  The Brown Idle Control System (ICS) is used to maintain idle control on all models from Sep 2019 to the present.  During cold or heavy loads at idle (ie: automatic transmission, electrical)  When the ECM detects a load and the reduction in RPMs,  the ICS solenoid opens the ICS vacuum pull and opens the throttle until the RPMs are at what the ECU commands.  The solenoid control is mounted on the passenger side TBI and is connected to the ECU through the wiring harness.  The ICS uses the Corvair choke pull-off for simplicity, availability, and ease of replacement and is connected by  3/16″ tubing.   Testing of the ICS can be done manually or through the use of diagnostic tools in the Tunerstudio program.  Adjustments to the rate/speed of reaction to RPMs are possible for different applications.  If low vacuum conditions exist in your engine, you may need a vacuum reservoir (Dorman  Part # 47083) to improve the idle-up condition after starting. If your engine has not run for a while, you may need to “tap” the accelerator to fill the vacuum reservoir and activate the ICS.

Air Conditioning:  Use of the Air Conditioning will require special modification to the harmonic balancer and will require sending the HB to us for that modification.    The ICS will try to correct the idle when the compressor engages, but because the IAC valve has to first sense the load, this can take time and may allow a rough idle or stall until the ICS corrects it.  This ECM does support A/C compressor control, but we are not supporting it in the kit.

Forward Control/Wagon:  If you use a harmonic balancer on this engine, you will not be able to use the bolt-on timing wheel unless the bracket is shimmed or a 64 rear engine bracket is used.   You may also need to shim back the motor support bracket to allow the installation of the cooling belt without interference.  You may have to rotate the engine to clear the belt around the timing wheels bolts. To use the timing wheel on the low horsepower pulley, DO NOT use the spacers behind the timing wheel.

Air Cleaners:  Owners have different ideas about air cleaners so we leave that to the end-user.  The TBIs will accept Corvair Factory Air Cleaners (2″ inside diameter) but may require modification for “hold downs” that secure the cleaner to the TBI based on the air cleaner used.  Many aftermarket air cleaners that will attach to a 2.25″ outside diameter will also work, but user modification may be needed.

Idle: 800-850 – Balance TBIs by using “just closed”, adjust the throttle rod between the TBIs, and then open the idle screw until a smooth idle is achieved in Neutral.
Spark Plugs: .35-.40 gap
Timing: Approx 16-20 degrees at idle.
Fuel: Premium is recommended for all Corvairs, but mid-grade may give good performance at a lower cost in cooler climates.

Check Timing with a Timing Light: During warm idle, the GM mark on the harmonic balancer should align with the bolt within 6 degrees on either side. Timing will be moving back and forth approx 6 degrees as the ECM uses the timing and ICS motors to maintain idle speed. The Center of the bolt is approx 26 degrees and would emulate a running distributor with the vacuum advance connected.

General TIPS:

Make sure you have a good starter. A starter that misses engagement spins a creates a high-frequency signal across the entire vehicle.  The ECM may sense that signal as engine RPM and will start injecting fuel and cause a flood situation On EFI, if a flooding situation ever occurs, press the accelerator to the floor (past 70%) and this will stop of flow of fuel while cranking.

Normal Readings/observations to be used as a guide
• Timing – Approx 20 degrees at idle
• MAP Sensor KPA – 50 @ idle out of gear 60 in a drive (+-10)
• Head Temp Cold – approx, 80 degrees
• Head Temp Hot – approx 220 degrees
• fuel pump will run for 5 seconds after key on
• Fuel pump pressure for TBI is 58 (+-5) lbs
• Crank sensor to Harmonic Balancer .050″-.10″

Troubleshooting (EFI system only):

We recommend a Laptop running Tunerstudio software (Free) and a Diagnostic Cable (included with kit) before you start troubleshooting!!! It will drastically reduce your troubleshooting time. MOST ISSUES OF THE EFI ARE CAUSED BY VACUUM LEAKS OR LOW/NO COMPRESSION.  If you plan to tune your engine using the laptop/Tunerstudio program, we recommend purchasing the upgraded version.  The saving in fuel and time will pay for itself within a few hours.  We will be glad to assist in your troubleshooting if you have your laptop connected to your EFI system and the laptop on the internet so we may access your system.

The engine will not run:

• Does ECM have Power? Switched and battery?
• Do Relay’s Click and transfer power? (Use voltmeter lead under relay housing)
• Does the Fuel Pump run for 5 Seconds and then turn off?
• Does the fuel pump have a minimum of 60 lbs of pressure when energized? • Pump hose may have slipped off the pump
• Does the Coil spark when the engine is cranked?
• Check the Relay system
• Check Relay ground
• Check switch power and ground to relay system
• Check 12V Battery to Relay
• *Check RPMs on the Computer when cranking, if none check the crank sensor and wire
• If RPMs are detected on 1st second of cranking then none after, the crank sensor polarity is reversed (Call Tech Support).
• Use a jumper to Test power with relays removed
Hard Starting (Eventually Starts/runs):
• Fuel Pump Failure – Check Static Pressure
• Fuel Pressure Regulator Failure (Check running Pressure)
Rough Idle:
• *MAP Sensor disconnected/malfunctioned (also check vacuum line)
• 1 or more of the injectors disconnected
• plug wire disconnected
• ICS Solenoid not connected/functioning
High Idle:
• Vacuum Leak
• Mechanical Idle Advance or linkage Binding
• ICS Vacuum pull malfunction
No/low Power when Accelerator is pressed:
• TPS disconnected (*Rotate to verify 0-100%)
• MAP sensor disconnected/malfunction (*Should read 100% with the engine not running)
• Low fuel pump pressure (less than 60 lbs)
• Injector Connector disconnected
Appears to be running extremely rich:
• Low MAP sensor vacuum (disconnected)
• Engine Temp sensor failure (If the engine not reaching operating temp (>180f), remove the connector from the temp sensor (this will put indicate 180 degrees for testing)
• High fuel pressure/Return line blocked/Lines Reversed
• Timing low
My engine will not turn off when the key off position is selected:
• Relay is being powered through the “Gen” light and needs Diode installed

*Computer needed for Diagnosis

Wiring Diagnostic Notes:

  • Power to Relay #1 & #2: (Power Feed to both Relays are from Battery 12VDC wire)
  • Power to ECM/Relay #1:  Switched 12VDC  activates Relay #1
  • Power to Fuel Pump #2:  Switched 12VDC  Powers Relay #2 and activated by ground from ECM.
  • The Main Red wire provides 12VDC to the rear terminals of the relay block.  Switched power energizes the ECM and terminal #1.  The #2 relay 12VDC (+) is provided by the switched 12VDC, but the ground (which energizes relay #2) is provided by the ECM (Pin 8).  If the ECM does not receive RPM information within 5 secs after initial power is applied, the #2 (Fuel Pump) relay will be disengaged and power to the fuel pump will cease.
  • The Idle Control Solenoid is controlled by Pulse Width Modulation (PWM) from the neg (-) wire of the ICS solenoid wire.  ICS should have 12VDC at the plug with the engine running (Fuel pump relay activated).
  • The O2 sensor is powered by the Fuel Pump Relay #2 and will only power the O2 sensor with the engine running.
  • TPS and MAP should have +5VDC on the grey wire.
  • Relay #1 provides 12V + power to ECM, Injectors, and Coil
  • Relay #2 provides 12V +  power to Fuel Pump, O2 Sensor, and Idle Control

My Fuel Pump relay will not disengage after 5 seconds with the switch on and not start the engine.

  • Ensure the Black O2 ground wire is secured to the head and the white is secured to the body.

Wiring Pinout Chart – Download here in PDF

Brown Injection Systems, LLC. assumes no responsibility for the function or suitability of the task of any kit or parts. This kit and parts are DIY (Do it yourself) parts to aid you in the installation of the fuel Injection of the Corvair. The ECM tune provided is a start for your tuning journey as each engine is different and may need adjustment for your engine setup/modifications.   We test-run each ECM and wiring harness on an engine to ensure the kit you kit will start and run as intended if your kit is installed properly.  Brown Injection Systems, LLC. Warranties this product against manufacturing defects for a period of 180 days from the date of shipping. This warranty covers all parts but does not cover outside labor to diagnose or repair without specific prior approval from Brown Injection Systems, LLC. This warranty does not cover any failures caused by misuse, accidents, or shipping incidents. Warranty failures will be repaired or replaced at the discretion of Brown Injection Systems, LLC., and the final decision. Any damages that may have occurred during shipping should be reported immediately to the shipper and not Brown Injection Systems, LLC., Inc. Brown Injection Systems, LLC is not responsible for any damages to equipment and possible liability injury that could result from the use of the product. Brown Injection Systems, LLC. Maximum total liability under any conditions is the repair or replacement of the product.  If the ECM is found to fail due to mis/reverse wiring, a repair charge will be charged by the manufacturer and the cost will be passed on to you.

PART TROUBLESHOOTING: If you feel a part is malfunctioning and needs to be replaced, we will do so with the following guidelines: 1) Troubleshooting is provided for 90 days after the shipping date, 2) Send the part to us, we will test and if part if found defective, we will give you a credit for future parts purchase at the lowest shipping rate (FedEx) to us. If the part is not found defective, you will be invoiced for the actual shipping costs incurred by us.

PRODUCT RETURN POLICY:  Most products can be returned for credit within 30 days of shipping. All returns must be as new for maximum credit and free of modification and scratches.  A 15% restocking charge will apply to any returned parts except for failure.  All returns shipping must be prepaid.  If you paid using PayPal, we will deduct the transaction costs from any refund.

TECHNICAL ASSISTANCE:  Technical assistance over the telephone can be obtained from Brown Injection Systems, LLC. at 864-617-1776 between the hours of 9:30 AM and 6:00 PM Eastern Standard Time. We may be assisting others, so leave a message and you will receive a callback.

“Brown fuel injection system is designed for off-road use only”
Revised: Dec 2019
Corvair Fuel Injection