This troubleshooting guide has been e-mailed / mailed to all SC owners and is now included in the kit. It's based on the tech advice calls we get.
We're 100% confident in the system. Our Supercharger warranty does not cover your original equipment items, such as injector connectors, crankshaft position sensors, fuel pumps, PCM, header type, etc. (it does not go beyond the parts we supply). All of these items can, and at times do, result in a poor running vehicle. Please keep this in mind when diagnosing a problem on a vehicle with aftermarket components installed.
Post Supercharger Installation Troubleshooting Guide:
This guide is based on the most frequent problems we’ve seen post Supercharger installation. The important thing to remember when diagnosing problems is that all the normal mechanical principles apply. Each cylinder must get the proper air, fuel and spark to operate properly. The Supercharger itself is simply an air pump.
Symptoms / Possible Causes / Fixes:
1. Engine runs good when cold, but poorly, or misses, when hot.
Improperly adjusted aftermarket rocker arms.
· Check rocker arm adjustment. May be too tight.
Old or faulty spark plug wires.
· Replace with lower resistance aftermarket wires.
Loose connection at fuel injector(s).
· Resistance to firing the injector goes up with heat. This can cause a loose connection to show itself. Using a mechanics stethoscope, listen to each injector when the missing sound is present to make sure they’re each clicking properly. If an injector is not clicking (firing), begin checking the connection at the injector, then between it and the VEC2. Tighten any loose connections. The injector connectors can be removed with the engine cool without removing the fuel rails.
VEC2 program card not fully loaded.
· Reload card.
2. One or both catalytic converters get hot.
Hot with check engine light.
· Note the cause of the check engine light. Most codes set will put the PCM into a safe “rich” operating mode. With the larger injectors, the extra fuel can cause the converters to get hotter than normal.
Spark plug or wire loose and not firing.
· The excess fuel from a cylinder that is not firing properly can cause the catalytic converter to overheat as it burns the raw fuel. Inspect the plugs and wires for proper installation and / or a wet spark plug.
Stuck open injector(s)
· You will not hear an injector click as it is full on. Disconnect the VEC2 from the factory wiring harness, reconnect the factory harness and test again (note that the engine will run rich without the VEC2).
Consider replacing a stock cat with a high flow, or removing completely.
· The stock cats have 4 substrates inside. They are designed for stock engines.
Vacuum leak within VEC2 system
· Use a vacuum pump and gauge to test for leaks. Connect the pump to the Tee fitting in front of the Supercharger, where it will pull a vacuum on the bypass valve and VEC2 hoses. The system should hold vacuum and the bypass should be full open by 10” of vacuum. A system with leaks will give an incorrect reading to the VEC2 controller.
3. Engine has a steady miss as RPM changes.
Loose connection at fuel injector(s).
· Resistance to firing the injector goes up with heat. This can cause a loose connection to show itself. Using a mechanics stethoscope, listen to each injector when the missing sound is present to make sure they’re each clicking properly. If an injector is not clicking (firing), begin checking the connection at the injector, then between it and the VEC2. Tighten any loose connections. The injector connectors can be removed with the engine cool without removing the fuel rails.
Spark plug or wire loose and not firing.
· Check plugs and wires for proper operation.
4. Engine runs poorly cold, but better when hot.
Improperly adjusted aftermarket rocker arms.
· Check rocker arm adjustment. May be too tight.
Improperly functioning oxygen sensor(s)
· Oxygen sensors must be hot and clean to produce the proper output voltage, which the PCM uses to determine the air to fuel ratio.
5. Engine has pinging (detonation) under boost at a particular RPM, or in a specific range with the *D card.
Spark advance too high.
· Change to a different card with higher number.
· Increase fuel octane.
Hot engine or heavy load when hot (6th gear heavy acceleration)
· Drop down a gear.
Configure a custom card for your car.
· Contact us with the following information: Card program you’re using, modifications to car, octane of fuel used, RPM area or range where detonation (pinging) occurs and manifold pressure level if not at full throttle (boost).
Vacuum leak within bypass / VEC2 system
· Use a vacuum pump and gauge to test for leaks. Connect the pump to the Tee fitting in front of the Supercharger, where it will pull a vacuum on the bypass valve and VEC2 hoses. The system should hold vacuum and the bypass should be full open by 10” of vacuum.
Blow-by oil in intake manifold.
· Check the breather system for oil contamination. If oil is getting into the manifold, the engine may smoke at start up. Choose another breather option from the manual, which eliminates the return into the intake.
Lack of fuel flow.
· Clogged / restrictive fuel filter.
· Faulty fuel pump / pressure.
6. Engine starts slowly.
Weak battery.
Cold plugs.
· Use alternate Bosch Platinum +2 spark plug # 4308 with preset gap.
7. At 1,500 to 2,000 RPM, the engine doesn’t sound as smooth as stock.
Short runner intake design.
· The short runner intake used in the system makes the smoothest power above 2,000 RPM, where the velocity in the intake runners is higher.
8. Check engine light is on.
Check the code.
· Utilize the factory diagnostics, as they are good at showing the cause of a problem. Plug a code reader into the diagnostic link at the left side of the driver’s side foot well.
9. Check engine light comes on for misfire code on cylinder(s) #X.
Loose connection at fuel injector(s).
· Resistance to firing the injector goes up with heat. This can cause a loose connection to show itself. Using a mechanics stethoscope, listen to each injector when the missing sound is present to make sure they’re each clicking properly. If an injector is not clicking (firing), begin checking the connection at the injector, then between it and the VEC2. Tighten any loose connections. The injector connectors can be removed with the engine cool without removing the fuel rails.
Spark plug or wire loose and not firing.
· Inspect the plugs and wires for proper installation and / or a wet spark plug.
10. Engine doesn’t sound like it’s firing on all cylinders.
See #9 and #11.
11. Engine runs poorly after I changed a card.
The card was not properly read.
· Turn the key off. Turn the key back on and attempt to reload the card.
The smart card file was corrupt.
· Change to a different card.
12. The engine idles poorly.
Vacuum leak within bypass / VEC2 system
· Use a vacuum pump and gauge to test for leaks. Connect the pump to the Tee fitting in front of the Supercharger, where it will pull a vacuum on the bypass valve and VEC2 hoses. The system should hold vacuum and the bypass should be full open by 10” of vacuum.
See #9 and #11.
13. The engine runs fine when cold, but sounds like it’s missing when hot.
See #9
14. The engine cuts out for a brief second at a mild acceleration.
VEC2 Firmware upgrade needed.
· Early VEC2’s had the first firmware version. The newer version corrects a bug in the program. Contact us about returning the VEC2 (control box and cards only) for the update. The new version double flashed the final green LED when the card is loaded.
15. Check engine light comes on for a high MAP voltage signal.
Vacuum leak within bypass / VEC2 system
· Use a vacuum pump and gauge to test for leaks. Connect the pump to the Tee fitting in front of the Supercharger, where it will pull a vacuum on the bypass valve and VEC2 hoses. The system should hold vacuum and the bypass should be full open by 10” of vacuum.
Poor connection at the MAP sensor.
· Check the MAP sensor vacuum hose and electrical connections.
16. The engine smokes when started.
Blow-by oil in intake manifold.
· Check the breather system for oil contamination. If oil is getting into the manifold, the engine may smoke at start up. Choose another breather option from the manual, which eliminates the return into the intake.
17. The engine idles high.
Throttle linkage improperly adjusted / hanging.
· Check for smooth and proper operation of the throttle body operating mechanism. Adjust throttle body alignment if necessary.
18. The engine idle hangs.
Factory PCM improperly adjusting the Idle Air Controller.
· Common problem in stock Viper PCM program.
19. I get fire out of my exhaust when I shift.
Excess fuel is being burned.
· When the throttle is closed, the fuel injectors remain on for a moment (all Vipers). When the exhaust is hot, the fuel can ignite in the pipe.
20. The exhaust burbles when I decelerate.
See #19.
21. #8, 9 and or 10 spark plugs are black.
Headers with oxygen sensors reading forward cylinders only.
· Move oxygen sensors to a location in the collector or only in the middle cylinder. Most common on Balenger headers.
Cold plugs.
· Use alternate Bosch Platinum +2 spark plug # 4308 with preset gap.
Rear cylinders run richer at vacuum.
· Run the car hard and check the plugs again to ensure they’re cleaning off as the manifold is pressurized, balancing the airflow.
22. My air fuel ratio gets leaner above 5,500 rpm.
Lack of fuel flow.
· Clogged / restrictive fuel filter.
· Faulty fuel pump / pressure.
· Too small of a fuel pump, line or injectors for the application.
23. My engine has an intermittent miss.
See #9.
24. My engine will not start.
Bad VEC2 or incorrectly installed wiring harness.
· Check wiring connections.
· Remove VEC2 from the system and test starting.
· Damaged PCM from improper wiring installation.
VEC2 program card not loaded properly / bad card.
· Attempt to reload the card / new card.
25. I smell a fuel leak, but am not sure where it’s coming from.
Leaking fitting or o-ring.
· Turn the key to the on position, let the pump run, then shut off. Check all fuel rail fittings, injectors and fuel line connection behind the motor at the quick connect for fuel residue. Replace or tighten fitting as necessary.
26. I have oil leaking from the vent on top of the blower drive housing.
Excess oil venting out.
· The case holds 120 to 150 cc’s of oil. We fill it to the maximum level when new. It will vent out any extra oil as it finds it’s own level.
27. I have oil leaking near the back of the supercharger.
Loose clamps.
· Check the location of the short hoses at the back and adjust the clamps as necessary.
29. My engine is running lean.
See # 22.
30. My crankshaft balancer hub / bolt fell off.
The crankshaft hub spun, unscrewing the bolt due to the direction of rotation.
· Use Loctite #271 (red) on the bolt threads and torque to factory setting of 250 ft / lbs. We have had no hub come off when this procedure is followed.
· Pin the crankshaft hub to the crank using our pin tool kit for an extra safety measure if required.
31. I have a 2000 (or newer) Viper and it breaks up at full throttle when hot (or sets miss fire codes)
Change the PCM to an alternate one.
· Contact us for an alternate PCM we’ve found to work better.
