2002 silverado, will not start. Again.

Discussion in 'Chevy Truck Forum' started by needshave, Mar 2, 2012.

  1. needshave

    needshave Full Member

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    2002 silverado with 4.3 L will not start. Earlier it would not start whenever it rained. It has got progressive worse to the point that it will not start at all. In the past year I have installed new fuel pump and fuel filter. It ran for a while until it rained then nothing. Recently changed distributor cap, rotor, coil and opened vent in distributor housing. At that point the engine would start, but would not go much above an idle. start to die. let up on fuel and in most cases it would return to idle. Installed new plugs and wires. No change. Took off ignition control module and had it tested. Tested good. Re install ignition module. no Change started the vehicle each day for three days to see if fuel pressure was being maintained. it started but no change, would not take fuel above idle. On the fourth day, would not start. fifth day would not start. Tried spraying ether down the throttle body and reconnect air induction to rule out any problems with Mass air flow sensor. Will not start. Several attempts with air induction on and off will not start. Anyone have any ideas? I'm fresh out! Thanks in advance.
     
  2. chevychase

    chevychase Semi-Admin
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    Are you getting a service engine light? If so need to scan ..could be a few things.
    Are you getting good spark at plugs? Also do not use ether..bad on engine .
    A bad map sensor will cause this also a maf sensor and a coolant temp sensor.
    Idle but no acceleration. What fuel pressure should have at least 58 psi and hold .
    Take a look at plugs for spark and signs of flooding.Hard to diagnose with out a code .. could be fuel injection stopped up
    Hate to guess ..waste money and time ..scan it anyways.
     
  3. needshave

    needshave Full Member

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    When I left it today, no check engine light. I will check tomorrow. I realize the concerns with ether, however, I my mind the engine should have fired and ran for an instant if there was sufficient spark. It did not, which tells me there is an intermittent disturbance that provides spark on one day but maybe not the next. Frankly I dont know what that is. I believe it sounds more electrical than fuel, In my opinion. What do you think? Do you think I should still run a fuel pressure test?

    Thanks
     
  4. chevychase

    chevychase Semi-Admin
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    Yes on the fuel pressure ..have a place to check on supply line at intake.
    Check spark.. and look at plugs ..More i think about it might be crank sensor.need to scan.
    But just guessing without a code.
     
  5. formulabruce

    formulabruce Senior Member

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    Replace the Ignition Module. get one with a warranty if possible. These can test good and have a case ground issue and not work when damp.
     
  6. needshave

    needshave Full Member

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    Scan

    I'm going to scan the engine hopefully yet today. Getting a scanner/reader from Autozone. The Crank sensor is one item I have never changed, on anything. Not sure how difficult that is. Probably going to find out though. Thanks again.
     
  7. needshave

    needshave Full Member

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    FormulaBruce,

    You're description is almost spot on. When it is damp or raining, it would always put up a fight. and Normally win. 9 out of ten times it would not start on a damp day and would run very rough until the engine got very hot. Thanks so much for your input.
     
  8. needshave

    needshave Full Member

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    I just scanned the 2002 for codes. NO codes. As it says PASS. Truck will not start. Even with a shot of ether in the air induction tube it will not start. It will try an fire twice maybe three times when you first try to crank it, with or without ether, on any given day. then no more the rest of the day. No matter how long or frequently you try and start it. Anyone have any ideas. I really don't see how it can be the fuel pump. it should run for just a few seconds on ether if it is starving for fuel.
     
  9. chevychase

    chevychase Semi-Admin
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    Like you said should try to fire with ether...which you should not use. When you sprayed ether did you hold throttle open? None will get to cylinders if not
    Actually going in the back door through throttle body only used for air intake..but if you hold throttle open should get enough to fire.
    Did you try ignition module like formula said? on intake beside dist. No code..hmmm. try disconnecting the map sensor..see what happens.
    Are you getting spark at plugs?
     
  10. needshave

    needshave Full Member

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    I did not hold throttle wide open. I pumped the accelerator but did not hold wide open. I will try that tomorrow. It odd for three days it would start right up, but not much above idle. Then would not even try and start. I have not purchased a new ignition control module, was wanting to get scan result first. I will try ether,with throttle wide open, then disconnect MAP, then check spark. Thanks for the ideas, any others?
     

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