1997 5.7L C1500 - Trouble starting after sitting.

Discussion in 'Chevy Truck Forum' started by dgwolfgang, Apr 26, 2011.

  1. dgwolfgang

    dgwolfgang Full Member

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    #1 dgwolfgang, Apr 26, 2011
    Last edited by a moderator: Apr 26, 2011
    It has been nice enough to ride my motorcycle to work so I haven't been using my truck as much. After my C1500 sits for a day or two it is becoming harder to start. The battery is good and the started is good. I have the 5.7l with 120k on it. I just replaced the fuel filter and added some fuel injector cleaner, per auto zone recommendation. This has had no effect.

    The thing is I can crank and crank it is trying but just won't start. I have pulled the air filter off and gave a quick blast of carb cleaner and that baby fires right up. this has ne to believe it is fuel related.

    Even if I just turn the key (not try to start) to let the fuel pump "prime" it makes no difference. I am stumped.

    Any thoughts?
     
  2. arcweldedprobe

    arcweldedprobe Full Member

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    When was the last time the injector and spider assembly was cleaned professionally, using a pump linked directly to the injector rail? Sitting for a day or two might allow goop to settle in the injectors--it's a big problem for the vortecs; assuming you have a vortec head. After it fires a few times (i.e., using carb cleaner to help), enough vacuum might pull just enough (with some heat, as well) to clear the injectors to [barely] allow it to operate. Just one possibility among several...hope you get 'er figured out!
     
  3. dgwolfgang

    dgwolfgang Full Member

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    When you say "cleaned professionally" I will answer no. I have had the truck for about a year and a half. I know I have never cleaned or have had them cleaned. I do have a vortecs cover on the engine, so should I assume it has vortex heads? Is cleaning the spider assembly something most of you guys do or do you take your truck to a shop? Thanks again!
     
  4. dgwolfgang

    dgwolfgang Full Member

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    I was thinking more about what you are saying about the injectors being clean. I think the issue is before the injectors. So I checked the pressure in the lines last night (after driving home from work) and this morning (truck sitting over night).

    Turn key to on pressure 60 psi within a few seconds drops to 30 psi. Then slowly drops from 30 psi to 20 psi. while idling is stays a constant 53 psi. By revving the engine it goes up to 60 psi then returns to 53psi.

    cold start, turn the key 60 psi then a hear a "click" then pressure drops rapidly to 20 psi. I did this about 5-6 times and the truck fired up pretty easily. . . . . thoughts any one?
     
  5. chevychase

    chevychase Semi-Admin
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    Might as well change the pump.. loosing pressure why your getting long crank times.
    Should hold pressure .. if it drops just a few not good.
     
  6. oneluckypops

    oneluckypops Senior Member

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    NO NO NO dont "change the pump" just because you loose pressure. doesnt mean the pump is bad, It could verywell be the injectors, regulator, check valve, line's, leaking causing the prime loss and the hard start,.

    BTW chevychase i am not saying that thepump isnt bad just saying thereare other things you can check BEFORE you throw parts at it. There is NO substitute for DIAGNOSTICS.
     
  7. oneluckypops

    oneluckypops Senior Member

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    FS Diagnostics 1 of 4.gif FS Diagnostics 2 of 4.gif FS Diagnostics 3 of 4.gif FS Diagnostics 4 of 4.gif
     

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  8. dgwolfgang

    dgwolfgang Full Member

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    this chart is great. here is what I did. Steps 2,9,14,16,20,22,24, and 25.
    Now it suggest checking faulty fuel pump, pulsator, or strainer. How do ou check these items.

    Also, I can get the truck started. While driving the truck I have zero problems. If the fuel pump is bad would I have issues constantly?
     
  9. dgwolfgang

    dgwolfgang Full Member

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    bump thoughts?
     
  10. greencamaro1981

    greencamaro1981 Full Member

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    nope fuel pumps are mysterious ive had them run barely then fine then none they are magic parts when in doubt replace it

    they can have the right pressure but low volume of gas usually problem get it flow tested at a diesel shop
     

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