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Engine starts, then immediately dies.

More trouble with my 1993 Buick Park Avenue. I just installed new spark plugs and ignition wires. Switched out the cheap copper plugs I initially bought for a nice platinum set. Found one of my new ignition wires was defective, returned it and got a new one. After that it stopped backfiring and smoking, but it still wouldn't run for more than two seconds at a time. It was making a loud "puff" type sound when it died and a friend suggested I look at emission systems. Seeing that a bad PCV valve could cause some issues I'd already had(rough idling, etc) and it was cheap, so I bought a new one and installed it. It no longer makes the "puffing" sound, but the engine still refuses to run for more than a couple of seconds. It sounds like it might be getting a poor fuel supply? I really don't know. I can keep it running for a bit longer if push the throttle, but it invariably cuts out after a while.

I'm still reading around and trying to build my knowledge, hoping I might figure this out somehow. Unfortunately, that noise was my only lead and it's gone now. I can't figure out what else could have changed here. Really, any help, even a push in the right direction would be greatly appreciated. Thank you very much for your time!

Comments

  • edited June 2010
    The problem might be with the ignition module.

    Ignition modules function two modes. These are the start and the run modes. When starting the engine, the ignition module goes into the start mode. This allows full battery voltage to reach the coil(s) to ensure that a cold engine starts. When the ignition switch is released and moves from the start position into the run position, the ignition module switches over to the run mode. The ignition module then steps the voltage down to the coil(s) because it doesn't require higher voltage to keep the engine running once it starts. Doing this also prevents the coils/plug wires/spark plugs from burning up from the constant higher voltage. So these components last longer.

    So it could be that start mode of the ignition module is functioning properly, but the run mode of the module has failed and the engine stalls as soon as the ignition switch moves to the run position.

    Tester
  • edited June 2010
    Thanks for the tip, Tester. I've pulled the module out and I'm going to get it tested tomorrow afternoon.
  • edited June 2010
    Can you hook up a pressure gauge to see what fuel pressure you're getting? Maybe it's dropping too low after the initial startup?
  • edited June 2010
    If you're going to have the module tested at the parts store, have them test it for at least twenty minutes. Sometimes it takes that long before a module shows up as being defective.

    Tester
  • edited June 2010
    Unfortunately, I don't really want to spend $30-45ish(that's almost a week's worth of groceries, y'know?) on a tool I'm probably not going to use again- or at least not anytime soon- and nobody around here rents them out. If it's not the ignition module, I'm going to try a new fuel pressure regulator and see where that takes me. Thanks!
  • edited June 2010
    I'll be sure and do that. Thanks again.
  • edited June 2010
    It's not a fuel pressure regulator problem so don't waste your money.

    It could be the oil pressure sensor, power is supplied to the fuel pump thru the OPS after the engine is running. It sounds like the fuel pump is running after the key is turned on but not getting power once the engine is running. There is a fuel pump test connector by the battery, it's a green connector. Apply battery power to it and see if the engine will start and stay running.
  • edited June 2010
    I think its worth the trouble to try to get your hands on a pressure gauge. Ask around among friends? Know anybody who works at a shop who would lend one?
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