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Noangel bought a Blazer: TBI questions though???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Leadfoot, Jul 22, 2002.

  1. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Yes I trailered home a 1988 K5 silverado for Noangel yesterday. Its got a black hard top, dark grey roof and lower stripe and a black accent stripe all the way down (looks sweet), it was the one in the for sale forum by Fugitive. It was a Florida truck so it has very little rust and one dent in pass door. Everything except the passenger power window works....or at least I thought. It has a bad head gasket but we were able to test drive it a couple of times (and it started fine). I picked it up yesterday and drove it on the trailer (unregistered) and I brought it to her house, when we went to start it to drive it off the trailer it wouldn't start (cranked over fine). It finally started but after we shut it off it wouldn't start again. It is a TBI unit and I am not familiar with these (Not saying it is a problem with the TBI, but most vehicles that I have ridden in with TBI start right up). The only thing I noticed is that with the key on there is a wire run from the alternator to the Positive terminal on the battery but it's spliced with a wire nut and the nut seems really hot. I am going to get a new cable and see if that helps, but does anybody have any suggestions for this TBI setup (as I am not familiar with this setup). Any help is appreciated even if not TBI related.
    Thanks in advance.
     
  2. Calclips

    Calclips 1/2 ton status

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    My TBI truck just up and died one day and refused to start. If you let it sit long enough or were working on it long enough, it would up and start and run GREAT (for a very short ammount of time when it would fall on it's face again.) It turned out to be the ignition module, I popped a new one in and the truck has run really great ever since then. While the module was bad, the motor would get no spark and the injectors would not get their pulse and thus would not dump gas down the throttle body.
     
  3. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Sounds like the issue. I looked down the throttle body and saw no fuel being sprayed. Where is the ignition module located (sorry for the ignorance) and approx. cost. Thank you very much. Chris (on behalf of Michelle).
     
  4. Calclips

    Calclips 1/2 ton status

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    The ignition module is under the distributor cap, just pull the two screws holding down the cap and you'll be able to see it. I got my module from CarQuest, and it was like 55 bucks after my buddy's discount. The guys at the parts counter said that there were two different kinds of module, but the cheaper one was junk and not to use it. The new module comes with some electric grease for you to smear on the bottom of it and then it just goes back on exactly the same way you took the old one off. I don't remember exactly what you have to do to get it off... but it isn't hard at all.
     
  5. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Thanks, I will check it out.
    P.S. Do you know if they can test the old one to see if it has crapped out? I don't want to replace it if I don't have to.
     
  6. Calclips

    Calclips 1/2 ton status

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    We did mine at our school's skill center, I couldn't figure out what the problem was... I replaced a coil and a fuel filter before then and it ran until I got to the skill center. The teacher there kinda took over the project as a way to show his students how to diagnose a problem like this. They had a multimeter out there and were checking all kinds of electronics and sensors... so there has to be a way to see if its bad, but I'm not an electric kind of guy (If ya' know what I mean).
     
  7. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    I understand completely. Thanks for all the help so far.
     
  8. Calclips

    Calclips 1/2 ton status

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    Not a problem, hope everything turns out fine.
     
  9. Twiz

    Twiz 1/2 ton status

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    First-off, congrats!

    Now:
    1- Turn the key to "on", can you hear the in-tank fuel pump? It should run for about a 2 secconds then turn off.
    2- Crank the engine, can you hear the fuel pump now? The fuel pump should stay running as long as the ECM is receiveing a dist. signal.
    3- Keep cranking, and watch the engine oil pressure gage if equiped (hopefully). Does the engine start and run when the engine oil pressure comes-around? The engine oil pressure switch is a "back-up" system, when it senses oil pressure it turns-on the fuel pump. (by-passing the fuel-pump relay)
    4- If the fuel-pump never turns on. Hit the fuel tank with a hammer, while someone holds the ignition switch in the "crank" position. This might free-up the fuel pump enough to start and run. (if this is the case, the fuel pump is bad)
    5- If the fuel pump works as intended, check for spark.

    That should help you along I hope. Good luck with it.
     

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