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hot start problem

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by kumma, Feb 7, 2002.

  1. kumma

    kumma 1/2 ton status

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    Ok im having problems with starting the jimmy after its been running for a while. 87 350 TBI, After an hour of driving and i shut it off, then try to start 5 minutes later it cranks over but wont fire. It runs extremly hot. I have used starting fluid and it starts right up and runs fine. Is my fuel pump going out? or what?

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  2. possum

    possum Registered Member

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    I had that problem for a while. Mine was the choke. The metal vacuum line was kinked where it had a 90* bend in it from the factory. I opened it up and it worked fine. Maybe when you're spraying the starter fluid you're opening up the choke enough to start it. Now I am by no means a mechanic but I had that problem and that is what my problem was. Try that first. It was a free fix, just required a little squeezing of some pliers. Hope it helps.

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  3. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    You need a carb to have a choke...[​IMG]

    Maybe low fuel pressure combined with the heat soak is causing a vapor lock? I'm pretty sure the fuel pressure should be between 10 and 13 PSI for the TBI. Are there any fuel lines routed near exhaust or anything?

    Rene

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  4. kpanza

    kpanza 1/2 ton status

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    Yeah, sounds like you're having vapor lock problems...like Rene said, check your lines to make sure they are not too close to headers, etc...you might also want to check the pressure you're putting out. Why is it running so hot? I'd say fix the "hot engine" problem first, then you will also solve the hard starting problems I think...
     
  5. kumma

    kumma 1/2 ton status

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    The fuel lines run on the opposite frame rail as the exhaust, they turn up to the engine about 8 inches away from the exhaust pipe. I wouldnt think they're to close. I dont have a fuel pressure guage. Is it possible for the line to vapor lock from heat in the engine compartment? I did notice the rad cap is defective, it hisses when i squeeze the radiator upper hose.

    Craig

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  6. BowtieBlazer

    BowtieBlazer 1/2 ton status

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    Vapor lock is just when the fuel evaporates before it gets to the TBI. Any extreme heat can do this to a gas line. Of course the radiator cap should be replaced regardless of whether that is the problem or not. Like the others said make sure the gas line is routed away from the exhaust especially if you have added in an extra peice of rubber line for a fuel filter or what not like many people do. If its a solid line and any area is in doubt try insulating it somehow or seperate it from the hottest are with a heat shield.

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  7. possum

    possum Registered Member

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    OK, you got me one that one.[​IMG] Guess I didn't read it too well. Well, at least my disclaimer about not being a mechanic was in there[​IMG]. Didn't notice he had one of those new fangled jobbies.

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