I have a 97 Cobra with v2 vortech supercharger. It has the older style mechanical fuel managment unit.

Car will run great at times, then will begin to feel as if it is vapor locking.
my understanding is these cars no longer can vapor lock. Smells like its flooding. Good spark, will cool down and run ok again. Fuel pressure guage shows pressure is increasing correctly while producing boost. Stalls, rough start,, have to hold throttle open and crack for about 10 seconds for it to start again,,, runs rough,, sputters, jumps,, no power,,, next day, will run fine on first start,, good for 30 minutes,, repeat. after rough start,, smells flooded,, puff of white smoke,,

any ideas where to start,,, everything appears ok,, no codes

 

i would say 02 sensor

 

o2 sensor?? there are no codes,, what would a bad 02 sensor cause,,


smells flooded,, is this a problem you have had in the past??

thanks for the suggestion.

 

i have seen o2 sensors make a car missfire, run rich, run lean, not run hardly at all...the fact that you said it only does it when it warms up sounds like an o2 sensor malfunctioning when it gets hot which is very common...also could be your IAC (idle air control) it could be stuck open or closed causing it to run rough

prolly the best thing to do is to go back to your dyno tuner and have him run the car and tell you before you blow it up from something simple

 

I'm assuming you have a blow-thru style MAF,More than likley you have an air leak somewhere in the intake piping AFTER the mass air flow meter. What happens is if you have an air leak after the MAF the MAF has already sent the data to the ECU in terms of the air flow and adding the proper fuel, but the air is leaking out before it makes it to the motor which will cause all the symptoms you just described to a T. It is also a possibilty that with a vacum issue you are having a problem with your FMU.