99 suburban wont start please help!!

Discussion in 'General Chevy & GM Tech Questions' started by durr711, Dec 3, 2010.

  1. durr711

    durr711 New Member

    Hi I'm Phillip I am new to this forum and I need some help.

    I have a 99 suburban 1500, 4x4, with a 5.7 vortech in it. It will not start it has spark and fuel but no fire. It will not fire off of starting fluid. I parrked it a couple of days ago and it ran fine went to start it a couple of days later all it does is turn over what could it be?

    Please Help!!

  2. stephan

    stephan Rockstar 4 Years 5000 Posts

    Hey Phillip, welcome to the GM truck club. If your engine will not fire off on starting fluid then you have NO SPARK..Trust me on this. That is some of the most volatile stuff made & if you had spark it would be lighting off.
  3. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Gotta agree with Stephan if it's not at least atempting to fire with starting fluid you have a spark issue.
    I see you determined you have spark, is it coming at the right time?
  4. phoebeisis

    phoebeisis Epic Member 5+ Years 1000 Posts

    Haven't we seen other posts where sudden starting-and running -problems on these 5.7's have been traced to some relatively cheap part?
    I want to guess throttle position sensor or some other sensor like this?
    I know I have read this type thread before, and it has had a relatively easy/cheap fix.

    Maybe stephan or TBplus10 can elaborate on this?
  5. durr711

    durr711 New Member

    THanks guy I'm goiing out there to work on it somemore today i'll let you guy's know whats going on.

    ---------- Post added at 12:51 PM ---------- Previous post was at 12:20 PM ----------

    Hey guys just got in from working on the truck got fire now and it wants to run backwards. Do you guys have any ideas??

  6. stephan

    stephan Rockstar 4 Years 5000 Posts

    What did you do to get spark to it Phillip? No spark before, but now you have spark? You must have done smth to fix this.
    Also... on running backwards. Describe this as best as you can... Do you mean it attempts to run backwards as you are shutting it off, just on the last revolution? Have you been messing with the distributor? Is this how you got it to fire today was by turning the distributor? You need to give us more information..
  7. durr711

    durr711 New Member

    I put new spark plugs in it and it has spark now. And no I did not mess with the ditributer any. When you are cranking it and you let off it turns backwards and breaths out the intake.
  8. stephan

    stephan Rockstar 4 Years 5000 Posts

    OK, this sounds like it has too much initial spark advance. It's firing too many degrees btdc, & is trying to push the pistons back down as they are on their way up on compression. Check & see if your distributor is loose. Don't try & move it too far or you will make matters worse. If it's loose, you should take it to a shop, unless you have experience setting timing on computer controlled engines.. Even if it's not loose, have a GM tech check it for you because it is too far advanced & the computer can only adjust it so far, because the parameters it works within are limited.
  9. durr711

    durr711 New Member

    What could cause it to do that over night?
  10. stephan

    stephan Rockstar 4 Years 5000 Posts

    Probably Murphy & temp change from getting stone cold overnight... Engines are more difficult to start when they're cold. What caused it to magically get spark all of a sudden?
    I'm just telling you what it's doing, BASED on what you're telling us.

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