2000 Grand Prix GT 3.8L 4T65E
Brief history: Bought the car with 121000 miles. Right front fender damage but sub-frame and other structural parts are straight. The transmission would shift hard so I figured the EPC was set to max. The engine would run rough with a bad miss. Initially DTC's 0716, 0303, 0203. After troubleshooting discovered that transmission 20 pin connector wired incorrectly and after rewire the hard shifts are gone. Also found bad wiring in harness, rubbing against AC accumulator. Input speed sensor wire(red/black) and others repaired. Checked #3 injector wire to control circuit, OK. There are now no codes after about 300 miles of driving and the car runs perfectly.
New problem: Sometimes the car just stalls; no fuel pressure. Replaced the fuel pump(knee jerk reaction). Still stalls. After toubleshooting there is no signal to the fuel pump i.e. no prime signal and no run signal. Let it sit for a few hours and it starts right up. Also if I, immediately after stall, jump the positive wire to the fuel pump it starts right up. Remove the jumper and it stalls. There are still NO DTC CODES! For some reason the fuel pump signal just disappears and then after a while it comes back.
Question: Does anyone have the PCM pinout for this car? I'm trying to figure out if the PCM is telling the fuel pump to prime when the ignition key is in the 'ON' position immediately after a stall. If the signal is being output from the PCM then why is it not at the pump? Any ideas?
Any help regarding this issue will be greatly appreciated.
