99 suburban problem

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by rwslippey, Feb 19, 2010.

  1. rwslippey

    rwslippey New Member

    Hello Ladies and Gents....

    Having a big problem with my 99 chevy suburban....

    Ok here is the symtom... (forgive me I'm not much of a mechanic)

    Startingg...... (turns over just fine) however.... if the vehicle has sat for more than 10 hours (it starts right up... drive on... but iff the vehicle has been ran and then shut down and you try again to start it in say anywhere from 20mins to 8 hours... you have to crank and crank , again it turns over ... just won't fire).... obviously with the way this goes the closer you get to the 10 hour park the less you have to crank it.

    99 chevy suburban 2500...

    Thanks to all that can lend a hand
  2. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    454? 4WD? check engine light on?
  3. rwslippey

    rwslippey New Member

    appolgoies ...

    yes 454 and 4wd....

    no check engine light is not on...
  4. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    Where do you live, what is the weather like while you have been having this problem? sub-zero temps?
  5. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    My first thought on hard warm starts is a fuel pressure regulator (FPR) problem. I see it all the time in the early Explorers, and, since your 454 uses a very similar fuel system, I might suspect the same problem. What happens is the diaphragm in the FPR develops a leak. After running the engine, the excess pressure in the system bleeds through the diaphragm into the intake/vacuum system -- effectively flooding the engine, which makes it hard to start until that excess fuel has dissipated.

    Easy enough to check. From what I understand, the FPR on your 454 is outside the intake (unlike my 350) and has a vacuum line attached to it. Next time you run the engine, simply pull that vacuum line off of the FPR and see if there's gas in that vacuum line. If there is, you need a new FPR.

    If that doesn't yield anything interesting, the next thing I might do would be to put a fuel pressure gauge on it and see what fuel delivery is doing differently on warm start vs. cold start.
  6. rwslippey

    rwslippey New Member

    Well I appriciate the idea... come to think about it... I forgot to mention that after the cranking start I can smell an odor of gas occationally... ... I'm gonna go check this out now...

    thanks again... I'll post results here...
  7. rwslippey

    rwslippey New Member

    ok I just took a look for the fuel pressure regulator ... and didn't dig in too far and noticed an odor of gasoline coming from the air filter... Opened it up and it was.... detently damp on the air intak hose from the air filter..... I would assume this is not good.. ... however I was unable to locate the fuel pressure regulator after trying to trace a few of the vacume lines... any ideas?
  8. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    I have no idea where GM put the regulator on the 454. I know where to find it on my 350, but not on the big block. If I were trying to find it, I might start by locating the fuel lines underneath -- identify the return line (the one without the filter) -- then follow that back up to the regulator.

    Anyone here with a 454 help him find the regulator?
  9. rwslippey

    rwslippey New Member

    I have been told it's located behind the distributer.... which is a bad spot to get to...
  10. chevydawg1

    chevydawg1 New Member

    I am having the same problem with my 99 2500 4x4 with 7.4l. rwslippey, Have you figured out if it was the regulator or not? It looks like you will have to pull the upper plenum to get to the reg. I figured when I do mine, I will check the injectors, replace dist cap and rotor etc, and replace the regulator diapham. I love my SUB but this prob is making me :grrrrrr:. Hope you get it repaired....let me know what you find. Thanks...


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