97 Suburban hard to start

Discussion in 'Chevy Truck Forum' started by tresguey, Nov 27, 2008.

  1. tresguey

    tresguey Full Member

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    1997 Suburban 7.4 4X4. This is my fiancee's truck and we are having problems starting it. Especially in the morning. I think it has something to do with oil pressure. Because when i crank it over in the morning it takes a good 6-10 seconds for it to start. And I have noticed that there is not pressure for the first 5 seconds I crank it. And it fires up when the pressure hits about 30 psi. After it starts i have good pressure about 90 at first the drops to about 60 when its warm and it runs normal. I can turn it off and restarts normal. I can even drive it to work and have it sit for about 8 hours and it fires right up normal. But if I let it sit for more than 12 hours it takes 6 - 10 seconds to fire up.

    One thing that I did notice is she has a non-4X4 radiator in it and whoever instaled it bypassed the oil cooler in the radiator bacause of a wrong size fitting. I am planning on installing a stand alone oil cooler soon. just haven't had the time yet. I was thinking that maybe the oil was draining back in the pan from the cooler lines being looped and tied off in a high place.

    Any help would be great.
     
  2. gmctrucks

    gmctrucks Full Member

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    I don't think that the oil pressure would be it but I may be wrong. If I were you I would get up early when it's dark out and have someone try to start it and see if you see any aching/sparks anywhere in the hood area im thinking that moister is getting into you spark plug wires or something and that's what causing it to do that.
    Good luck! GMC
     
  3. leolkfrm

    leolkfrm Full Member

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    How's the starter and battery, how fast it turns over when cold will affect starting time
     
  4. purplehavoc

    purplehavoc Full Member

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    Have you checked fuel pressure?
    Sounds like fuel may be bleeding off when it sits and takes a few
    seconds of cranking to pick it back up.
    Your oil cooler lines won't have anything to do with your starting.
    Is your ign. system in good shape as well?
     
  5. tresguey

    tresguey Full Member

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    I will check fuel pressure and ignition. I thought there may be some sort of low oil pressure sensor that kills the engine that I was unaware of. Because for some reason it seems to start after i crank it over enough to hit 30 psi of oil pressure. As for the battery and starter, I just put a new starter in about two months ago. And it cranks fine. this problem has been going on for about 6 months now. And I have finally have time to really look into it. from what little info i get from my fiancee about the truck. She bought it from an old friend that had the engine rebuilt for her. Looking at it I can see that whoever did it really didn't care or didn't know much about vehicle care. Not saying I'm an expert. I will post what I find on the ignition system and fuel pressure.
     
  6. stumpuller454

    stumpuller454 Well-Known Member

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    fuel pressure should be 55-60psi and volume around 1 pint per minute......
     
  7. 87c10slammer

    87c10slammer Senior Member

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    try priming it first before you start it.. turn the key to the on position for about 20 seconds before you start it.. it lets the fuel pressure build up so you wont kill your starter.. i had the same problem with my 4.3.. it was the fuel pressure regulator.. after i changed that it was no problem
     
  8. tresguey

    tresguey Full Member

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    I went to check out fuel pressure, I turned the key over to the run position and the pump was not on. shouldn't it be on at this point?
     
  9. bigz

    bigz Banned

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    yeah should be
     
  10. gmctrucks

    gmctrucks Full Member

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    I don't know about that could it be primed already that it won't kick in meaning the fuel pump guys???????????
     

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