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  1. #1

    Default 1998 vortec no start when cold

    Ok when this is cold you can crank it untill the batteries die it will not start, give it a little gas down the intake and it starts right up. Every time after that it will start on the first turn of the key all day long, let it sit over night and you have to put gas down it's throat. It has good fuel good spark good grounds, two good batteries, new distributor, new wires, new plugs, new temp sensors, new starter and a completely different engine with all different sensors and fuel injection because the other engine had a little more blow by on two cyl. Thanks. 1998 K1500 Suburban.

  2. #2

    Default

    Ok when this is cold you can crank it untill the batteries die it will not start, give it a little gas down the intake and it starts right up.
    Because it will start when you put a little gas in the intake suggests that the problem is a fuel delivery problem. You say it "has good fuel." How are you verifying fuel delivery when it won't start?
    '98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
    '92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
    "My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World

  3. #3

    Default

    On the first motor I was thinking vacuam leak so I took the lower and upper intake apart, cleaned and put back together. The fuel pressure was I think around 52-55 psi and had good volume. I also installed a relay switch so I could run the pump non stop. What has got me is how it starts great even when hot.

  4. #4

    Default

    If I may ask, was that fuel pressure measured while trying to start it when it wouldn't start?

    The next thing I'd be looking at would be the injectors. Are they firing when it won't start? Is gas getting through? Maybe pull a spark plug and see if it is "wet." If there's no indication of gas getting into the cylinders, then I would look closer at the injectors/poppet valves.
    Last edited by MrShorty; 09-28-2011 at 09:46 AM.
    '98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
    '92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
    "My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World

  5. #5

    Default

    OK when it is cranking there is 45 psi, when it is cranking I also checked and there is no injector pulse.( I checked it with a low impedence test light)

  6. #6

    Default

    Quote Originally Posted by conman13 View Post
    OK when it is cranking there is 45 psi, when it is cranking I also checked and there is no injector pulse.( I checked it with a low impedence test light)
    yeah, but the injectors should be OK, since it'll run fine after your little "gas pour" fix. It seems like there is something obvious and simple here... I just haven't put my finger on it yet. A game of twenty questions should help solve this. Are you able to test an injector outside of the truck? Not sure what capability you have on hand...
    I like you.

  7. #7

    Default

    OK I just did a injector pulse test and all 8 injectors flowed the same . I did some more testing and found that the pass lock system shuts the injectors off if the capacitors give the wrong voltage or the pass lock sensor could be bad, so now I need to find the capacitors that are some place around the shift lock. Any ideas?

  8. #8

    Default

    Does anybody know how to relearn the passlock system? Thanks.

  9. #9

    Default

    ck your fuel pressure regulator,that is supposed keep pressure at the rail so it fires right up.Small round item should be on drivers side.Single vacuum hose coming out if you pull that hose and smell gas you have your gremlin.Oh and they are easy to change and cost very little.

    45lbs is low for that truck KOEO should be closer to 60psi.But that again could be the regulator.

  10. #10

    Default

    I put 13 volts straight to the fuel pump and got 58 psi when cranking and still did not start and still had no injector pulse, but here is another piece of the puzzle, last night I plugged in the block heater and this morning it started right up.

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