Strange Stalling Issues
Thread Starter
Staging Lane
Joined: Jan 2015
Posts: 58
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From: El Paso Tx
Strange Stalling Issues I have an '87 Monte SS with a LS2/4L65 out of a '06 GTO. The car has a PCM and wiring harness from PSI Conversions. I converted the to a cable operated throttle body, so the PCM is from an '02 Silverado 2500. The power supply to the PCM comes from the starter and the ignition relay power comes from the old Monte ECM power supply, under the dash on the passenger side.
So around February, the car would stall occasionally when turning right. I would notice it a little more when braking and turning right. It led me to believe that perhaps the source of the stalling was caused by the ignition switch in the steering column. Normally, I would place the car in neutral and restart the car, I wouldn't even have to stop to do so. Then I began to notice the car took longer to restart. If I cycled the key once, I could hear the fuel pump pressurize and the MIL light would come on in the dash. Then one day it stalled when I was backing out of my driveway. I could not get the car to fire, it would just crank endlessly. The fuel pump would not pressurize and the MIL would not longer turn on.
I replaced the ignition switch but the car would still not fire. I next checked the power supply to the ignition relay and it check out...12 volts with the key on. The fuel pump relay is triggered by the PCM its power supply comes from the back of the alternator (Racetronix GN harness). It finally led to me removing the passenger front tire to give me better access to the wiring harness. I asked my wife to place the ignition on the run position and I wiggled the harness...the Fuel pump engaged and the MIL light turned on. I next fired up the engine. I checked the bolt at the starter to see if it was loose. I did give it a 1/4 turn, easily. Still, I feel it was not the source of my problems.
The car now will stall when idling in Park or Neutral. Another strange development is that after it stalls, the fuel pump and MIL won't work when I cycle the key and place it in the Run position. If I turn the key to crank the engine, the MIL will come on somewhere between Run and Start. The car fires up and runs...weird.
I'm not sure what to do. If I were to go out now and place the key in the run position, the MIL and fuel pump work but not after it stalls. I have no stored trouble codes and do not appear to have a vacuum leak. Can the PCM be bad? How do I check that out?
Sorry for the long post, I just want to give you guys as much info as possible.
Thanks,
Jose
So around February, the car would stall occasionally when turning right. I would notice it a little more when braking and turning right. It led me to believe that perhaps the source of the stalling was caused by the ignition switch in the steering column. Normally, I would place the car in neutral and restart the car, I wouldn't even have to stop to do so. Then I began to notice the car took longer to restart. If I cycled the key once, I could hear the fuel pump pressurize and the MIL light would come on in the dash. Then one day it stalled when I was backing out of my driveway. I could not get the car to fire, it would just crank endlessly. The fuel pump would not pressurize and the MIL would not longer turn on.
I replaced the ignition switch but the car would still not fire. I next checked the power supply to the ignition relay and it check out...12 volts with the key on. The fuel pump relay is triggered by the PCM its power supply comes from the back of the alternator (Racetronix GN harness). It finally led to me removing the passenger front tire to give me better access to the wiring harness. I asked my wife to place the ignition on the run position and I wiggled the harness...the Fuel pump engaged and the MIL light turned on. I next fired up the engine. I checked the bolt at the starter to see if it was loose. I did give it a 1/4 turn, easily. Still, I feel it was not the source of my problems.
The car now will stall when idling in Park or Neutral. Another strange development is that after it stalls, the fuel pump and MIL won't work when I cycle the key and place it in the Run position. If I turn the key to crank the engine, the MIL will come on somewhere between Run and Start. The car fires up and runs...weird.
I'm not sure what to do. If I were to go out now and place the key in the run position, the MIL and fuel pump work but not after it stalls. I have no stored trouble codes and do not appear to have a vacuum leak. Can the PCM be bad? How do I check that out?
Sorry for the long post, I just want to give you guys as much info as possible.
Thanks,
Jose
