Check engine light on a supercharged Viper

[SMCBUILDERSINC]

How many of you s/c guys throw a check engine light from time to time? Im told that there is a very fine line on these cars where the computer can be fooled to thinking that all engine parameters are normal. Theres a tuners car that I know of that always throws the light and the code reads something to the extent of "low voltage to the mass air senser". The only correction is to run the car really rich at idle, around 10.5 to 1, this solves the light but puts the engine out of tune.

 

[1TONY1]

What code # is it showing ?

 

[kverges]

I throw a misfire code once in a while, but have not for a long time. You have to read the code, then go from there. The light alone could be anything, including a problem unrelated to a check engine light. Sean Roe sells an inexpensive code reader that will also clear codes. Get it and see what is going on for sure.

 

[GaryA]

I think you meant MAP (Manifold Air Pressure) sensor. There isn't a mass air flow sensor on the Viper.

My Heffner S/C car has never thrown a check engine light after about 6000 miles.

 

[SMCBUILDERSINC]

Yes it was a MAP sensor.

 

[MaxedGTS]

no check lights here 30,000+ miles. i still am wondering how bad the factory injector clips are but nobody seems to want to answer my question
Max

 

[Sean Roe]

A Superchargerd engine would be more susceptible to a MAP sensor voltage high code than a low voltage to the MAP sensor code. The PCM has a value range that the MAP sensor is expected to be in based on throttle position and engine RPM. If the voltage range of the MAP is outside of that, due to forced induction, the PCM would most likely set a MAP sensor voltage high code. A low voltage TO the sensor code would be more indicative of a fault in the PCM circuit that provides the 5 volt reference signal to the MAP sensor. I'd swap the PCM with another car and see if it goes away.

Regards,
Sean

 

[Sean Roe]

...... i still am wondering how bad the factory injector clips are but nobody seems to want to answer my question
Max

They're awful. If someone has a really good digital camera that can take up close pictures, I'll send them a factory terminal end and a good terminal end. The pictures my camera takes are too blury.

A good picture, or looking at one in person, would probably clear up your confusion.

Regards,
Sean

 

[1TONY1]

no check lights here 30,000+ miles. i still am wondering how bad the factory injector clips are but nobody seems to want to answer my question
Max

How bad they are......or.......why they are bad ? I will make a closeup pic of the two connectors this weekend. If you can imagine sticking a butter knife in between the prongs on a fork, the fork is like the stock connector with two vertical prongs and the flat blade of the injector goes between. The good connector has four sides and keeps spring loaded pressure on the injector blade.
The real question you have is .....(I asked myself also) Why is no one having trouble except the Roe s/c cars ???? Well, first.....I have personal knowledge of a stock cream puff that took three dealers to diagnose one bad injector connector after all other ignition parts were replaced and comppression tests etc were run. So there are others out there with the problem. (they may not know it because it is very intermittant)

I think the difference in the Roe cars is: With a stock intake the harness is below the runners and the connectors have some "hanging weight on them". After the s/c the harness is laying on the top of the intake and no longer has weight on it......kinda in a neutral position. That is my best "guess"

 

[MaxedGTS]

Thanks for responding but i wonder why the factory injector clips have not set a code EVER on my DLM car. honestly..... im not being mean or anything like that. i just wonder what the difference could be btween the two systems. Ive been wondering this for some time now. You got to admit its very puzzling.

Max