For some odd reason my car has been cutting out really hard at 7k rpms sporadically. Occurs more often in 3rd and 4th when i'm sitting in the high rpms longer.

I have plenty of fuel pressure, my map is tuned through PFS Purple Box for 10.5 AFR.

Just changed the plugs and it seemed to clear up a little

- Driving along under WOT and then the car makes a loud BAM (kind of like a backfire but weird sounding) and the car bucks like hell, almost as if hitting a wall

Could this be ignition breakup? Or you guys think maybe the fuel pump is cutting out?

 

sounds like ignition brake-up.
do you have a ignition amp?

and im sure you know loud bangs are not good.

 

Try moving the stock knock sensor to the rear rotor housing. A common issue with the PFS is that it over-reacts to the stock knock sensor. Relocating typically fixes the issue (you may need to extend the wires).

 

well I drove it again to make sure I was correct in my explanation. At 7k rpms, randomly, it sounds exactly like the old stock ecu 14psi fuel cut. Car makes an immediate loud BANG from the exhaust and dives as if immediately releasing the gas pedal. I'm too scared to hold the pedal down when this happens?

Its never done this before...i've had the car for 2 years with the pfs? Its even done this in first gear. Could this be an injector wire corroding out?

So first thing to try is relocate knock sensor?


I can't see how this is breakup. It happens at 10psi, but rarely. It does occur more often around 11-11.4psi on the Profec B. However, isn't breakup generally consistant? I thought breakup sounded like sputtering....its the same feeling of running too rich where the car falls on its face and runs really choppy under throttle? This is NOT that at all, this is simpy the feeling of cutting the car off at 7k rpms in the middle of WOT

 

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