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tmerrit211
tmerrit211 2/7/2013
1993 Chevrolet Lumina Base 6Cyl3.1L - Engine
Runs fine for 3 to 5 minutes then stalls. Can't restart until a couple hours later.
Seems to suddently lose spark or fuel after 3 to 5 minutes. Something is shuting down the engine and won't restart. No engine light or error code (OBD1). Runs fine again for another 3 to 5 minutes after waiting a coulle hours.
4 Answers
  • HouseCallAuto
    HouseCallAuto 2/8/2013
    You have to do a fuel injector resistance test. This is the classic symptom of a shorted fuel injector. Do not, I repeat do not go changing all kinds of sensors. The only way to check this is as follows. There is a greater than 99% probability here that you have at least one really out of spec injector which as the engine heats up for the first few minutes causes the resistance to get so out of range that the injector driver circuit within the ECM shuts down causing no injector pulse. Then after a range of minutes to few hours, the resistance comes back within range (as is what happens when things cool down) and the ECM comes alive again.

    1. Remove the upper intake plenum, check fuel injector resistance.

    2. Each fuel injector should have just over 12 ohms.

    3. Replace any injector under 12 ohms when warm.
    Reply
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    HouseCallAuto
    tmerrit211 2/9/2013
    Sounds good but by the time I remove the intake manifold so I can get to these injectors they would cool down. Also wouldn't I get a check engine light and an error code if this happened?
    HouseCallAuto
    HouseCallAuto 2/9/2013
    No it will not set a code or check engine light.
  • HouseCallAuto
    HouseCallAuto 2/9/2013
    I can lead you to water but I can't make you drink it. There are two injectors that you can access without removing the manifold. get a noid light set from the auto parts store on free loan. When the car is cold, remove the injector connectors one at a time. Plug in the noid light. Crank the engine over. You will see the noid light flash. That is just so you now what you are supposed to be able to see. Do it to both injectors that you can get to. Now plug them back in and remove the noid light. Start the engine and run it until the engine stalls. I will bet you that after the engine will not start that you will still have spark (you have to check) but you will have NO injector pulse if you now check with the noid light. Do it. As far as checking the injector resistance, all ya need is a digital ohmmeter. But if you do what I said and you lose the injector pulse, that would mean that you will go ahead and replace all 6 injectors. Additionally, do not use remanufactured injectors as they have a high defect rate. You only want to do this once. Thats all I got for you. Do not ignore what I have said here.

    Bad injectors on GM engines existed between 87 and 93 with the use of Multec injectors. I have come across this situation many times in my auto repair career and the symptoms all seem to be the same. Car starts and runs seemingly normal until the engine starts to come to temperature. Then without warning the engine begins to misfire and stumble for a minute or less and the engine stalls and will not restart until it sits for varying amounts of time, typically an hour or more. Sound familiar?
    Reply
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  • tmerrit211
    tmerrit211 2/13/2013
    I finally got an error code 42 (Electronic spark timing monitor error). Replaced the Ignition timing module. That worked.
    Reply
    0
  • felplay auto repair.
    check crank and cam sensor signal when not start it.
    Reply
    -1
    felplay auto repair.
    tmerrit211 2/9/2013
    How would I do this without expensive equipment? It also seems that this signal is present for the first 3 to 5 minutes. What whould change to cause the loss of it?
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