fuel pressure regulator ???

Discussion in 'Performance & Fuel' started by drradon, Dec 30, 2008.

  1. drradon

    drradon New Member

    I've been having persistent problems with my '99 silverado - when I start up in the morning, it seems to idle fine but when I take off, it begins to kick and miss and run really rough. Sometimes it will sort itself out but sometimes it won't. I've had the fuel pump, ignition module, plugs, ignition wires replaced but the problem persists. I've been told to check the fuel pressure regulator but I need to find a diagram of where it is: I've looked at a couple of sites - but the diagrams don't look like my engine. I've begun to think the engine is a '98 model rather than a '99. It was purchased in early 1999.

    Two questions: is there any easy way for me to tell what model year the engine is (it's a 4.3 l engine)?
    If so, will I need to remove the intake manifold to get at the FPR?

    Many thanks.
  2. sdavis2702

    sdavis2702 Rockstar 100 Posts

  3. drradon

    drradon New Member

    That's what's making me crazy - I can't find the d***d thing - when I look at my engine, the fuel rail seems to be buried. Mine is a 4.3 l engine too - but when I looked at the online manuals on the Ohio library site, my intake manifold doesn't look anything like the '99 diagram - but looks more like the '98. For the '98 model, the manual says I have to pull the upper intake manifold off - but I'll feel like a prime fool if I do that and still don't find the FPR.
  4. sdavis2702

    sdavis2702 Rockstar 100 Posts

    If you're sure that the engine you see under your hood is not the one you're seeing online for your year, shoot a picture and let us see. That's kind of strange but very possible that someone has made a swap in the past.
  5. drradon

    drradon New Member

    Photo of engine

    Thanks sd2702
    I'm a little new at this but I've attached a couple of photos of the engine from right side and left side - with the intake housing removed.
    Again, this is a 4.3 engine in a '99 model. It was originally purchased in late '98/early 1999

    Any thoughts would be greatly appreciated.

    and Happy New Year...


    Attached Files:

  6. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    My first thought is: why are we spending all this time looking for the FPR itself when testing the FPr mo9stly requires finding the test port in the supply line (kind of looks like a tire stem or AC test port) and attaching a fuel pressure gauge to it.

    In the second picture, I can see the fuel supply and return lines (not sure which is which) coming into the top of the fuel meter body just behind the throttle body. I don't see the test port, but it should be right there somewhere in one of those lines.

    FWIW, it looks a lot like the fuel meter body on my '98, and I would expect the FPR to be down inside the intake, just below where the fuel lines come out.
  7. drradon

    drradon New Member

    Hi Mr. Shorty,
    Thanks for your post - I guess at this point, it's simply knowing what I'm dealing with as much as anything else. I've seen a number of posts indicating that it was a gut-simple test and fix for the '99 engines - pull the vac line, check for gas, and spend 15 mins replacing if that was the culprit - in which case I'm a complete blockhead for being unable to find the bldy thing. If it's a '98, then maybe there's hope for me...
    In which case: what's a good place to look for a fuel pressure meter; what's it likely to cost; and do I need to test the truck on the road or can I test it parked (it seems to idle fine, and miss and buck mostly when I'm trying to make a modest acceleration); etc?

  8. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    Any self-respecting parts store will carry a fuel pressure tester. I paid ~$40 several years ago at Pep Boys. I've seen the same one at Autozone for about the same. Harbor Freight sells one for $10-15, though I don't know about quality.

    Basic fuel pressure test involves hooking up the gauge, turning the key on to see what pressure the pump generates (My '98 calls for ~60 psi, I expect your '99 is the same). Start the engine, the fuel pressure should be within a few psi of the engine off value.Goose the throttle, and the pressure should increase slightly then back to the idle value. When the pump shuts off, the system should hold pressure for a significant chunk of time.
  9. scooby2b2

    scooby2b2 New Member

    Fuel pume pressure regulator

    2 words. FUEL FILTER!......I have seen this same problem on a few of the shreiff office tahoes and trucks. Either the idle problem or it runs fine till floored and engine just dies or cant get over 2k rpms. Plugged 20 buck fuel filter.
  10. kilroy

    kilroy New Member

    I too can't get over 2K RPM or it dies - even going at 70MPH (hils are hard to climb and forget about passing) I will have to go change the filter.

    The irony is that we went to pick up the truck, it was running, gf wanted to see the baby, and we asked for the truck to be turned off. After we were done visiting tried to start the truck and it would not it cranked and cranked and cranked, to the point of almost killing the battery. So I gave up yanked the battery charged it returned the next day and it almost but started right up, alittle difficult but it started. Then I drove it 35 miles it did not sputter but I had to coax it up to 70 ... even 80 (leagal at places in TX :) ) - again I could not pass and had trouble climbing hills. (sorry to be so chatty)

    I will go buy a filter and post my results back, I promise I will be briefer :)

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