My nieghbor's porsche is cutting out at 4500-5000 at wot...just like a rev limiter. If you easy into it...it will pull to 6200+. We've checked fuel pressure,going down the road...it never drops. Swapped ignition module..nothing. It's throwing codes..26 ccp electrical fault, code 48..maf, and code 97 4000 ppm vss circuit fault. The car has no maf..it's speed density mode. It has a signal convertor for the tach. Of course it always shows 0 speed on the scanner. I've tried everything...tuning,putting in a stock '94 maro tune,and my tune.
It was supposed to have a lt4 in it,but the tuner cats vin reader on the computer,says it's a '94 lt1.
Could the lack of a speed reading to the computer have something messed up?
The fuel cutoff is set to 6350...

 

None of those codes should cause what you are seeing. You can shut off the 26 and 48 DTC's with a a tune, the 97 is an open circuit from PCM to speedometer , hanging a 10K 1/4 watt resistor on the line to ground will get rid of that. Only cutoff in the LT1 F-Body code is RPM. The speed cutoff in the F-Body stock tune is set to 255 MPH and yours is reading 0 so it should not have any effect. . And I assume the 944 is running LT1 F-Body code not the Corvette Y Body code. Since you verified FP during WOT, your cutout at lower RPM looks like spark, opti, coil. What are the exact symptoms, missing and recovering, stalling, backfiring. The normal RPM limiter cutoff causes popping and , bucking as the injectors turn off/on/off/on to hold the RPM down, it's very apparent when that happens.

 

yea the 48 and 26 has been cutouff...it still shows up in my datamaster logs.
MMM...how exactly do I check the code? It does it with the tune it came with, my tune for my ta in sig,and a stock 94 camaro tune.
When wot it's just like you killed it....backfires so loud,we think it threw a hand grenade out the tail pipe. If you only go about 3/4 throttle...it'll pull all the way to 6200+. If your easing into it and get to near 6k and then stomp it the rest of the way..it stumbles,backfires and dies back down to around 5k.
I forgot to mention...it has 1.6rr's. It has the corvette valve covers and dress up stuff....but I don't think it is. It doesn't even have the red intake manafold.