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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
For quite a while now, my 2008 Z06 has a strange behave. Sometimes she won't rev over 4000ish rpms. The engine is bogging and stuttering when it occurs. The problem is most of the time not occurring, but when the problem once is there, it stays till the car cooled down. What I found out, the problem only occurs when it is hot outside after some longer drives and when the fuel level gets lower (below 1/3 or so). A few days ago, the problem started and I directly drove to the next gas station and filled her up. I straight went back testing and she run perfectly again and revved smooth to 7k. Filling her up with fuel fixed it immediately. If I think back, it always was the same scenario: Hot outside, a longer drive and lower fuel levels. I never got a CEL till last time. There was P0171-00 in the readout.I have new oem plugs, wires, coils, maf and map sensor. That changed nothing. So it is not misfiring in the classic way.
Does anyone has an idea what the problem could be or had something similar? It really seems to have something to do with heat and fuel level.
A P0171 is bank 1 lean but bank 2 may be lean as well but hasn’t set a P0174 because your fuel trim hasn’t reached its limit to set that DTC for bank 2…with your scan tool see what bank 2 fuel trims are at…does your scan tool show “freeze frame data” ???…the diagnostic path for 1 bank lean is different than for both…watch your upstream O2 sensors at WOT…they both should go RICH…if not it could be something like a MAF sensor or fuel delivery…you said the MAF was changed so I’d look at fuel delivery…you may have a weak fuel pump or even the wiring…more heat equals more resistance…get yourself a fuel pressure gauge and see what the pressure gauge does under WOT…pressure should not decrease…fuel volume should also be looked at…you can start there…key on engine off fuel pressure should be 55-62 psi…my 08’s fuel pump current at key on engine off is 8.34 amps…if you had heat related resistance in the electrical part of the circuit your current would be less…if the resistance doubled the current would be around 4 amps if you used OHM’s Law.
07-14-2023, 04:12 PM
Hesitating/Power Loss above 4000rpm @WOT
