1995 Motorhome on P30 Chasis 454 won't stay running

Discussion in 'General Chevy & GM Tech Questions' started by Rascl93, Aug 28, 2012.

  1. Rascl93

    Rascl93 New Member

    I need some help and advice. We have a 1995 Gulfstream Sunvoyager motorhome on a P30 chasis. The engine was torn down when we bought it - long story short, after having heads redone, new piston, new valves, new lifters & rods, we have the engine back together. We have replaced both temp sensors in the heads (driver's & passenger's side), checked for vacuum leaks, new fuel pump, new cap & rotor, and still have a problem.

    It will start and run for a few seconds then shut down. If you can catch it before it shuts down and feather the throttle, you can keep it running, but not good. It will not hold a steady RPM.

    Suggestions please.

    Thanks.
     
  2. Rascl93

    Rascl93 New Member

    Forgot to mention - it's only got a little over 20,000 miles on it. Bank repo + trash through the throttle body = trashed piston.
     
  3. RayVoy

    RayVoy Well-Known Member 2 Years 1000 Posts

    It sounds like a classic fuel delivery problem.

    Pump, filter, or throttle body.

    With the info provided, I'd lean toward the throttle body.
     
  4. Skippy

    Skippy Member 2 Years 100 Posts

    Double check your wiring order. I've seen a lot of rough running engines with a single wire swapped at the cap.

    -Skippy.
     
  5. Rascl93

    Rascl93 New Member

    It will start, but then it shuts down. Almost like something is telling it to shut down. Wondering if we have a fuel pressure issue.
     
  6. RayVoy

    RayVoy Well-Known Member 2 Years 1000 Posts

    Perhaps, this was my answer in post #3
     
    Last edited: Aug 30, 2012
  7. Skippy

    Skippy Member 2 Years 100 Posts

    Is this a carburetor , TBI, or electronic injection fuel delivery system?
     
  8. Rascl93

    Rascl93 New Member

    TBI - and yes RayVoy, your post is what leaned me in that direction. No need to get snotty about it. :tongue: If you would have read my original post thoroughly you probably would not have mentioned fuel pump since I stated that it is new.

    Anyway, it is getting fuel to start. Just not sure where to go from here. Should I rebuild the throttle body or check in to the computer.

    Thanks everyone for your input.
     
  9. RayVoy

    RayVoy Well-Known Member 2 Years 1000 Posts

    Sorry Rascl, that was not my intent, just wanted you to reread my first post.

    I saw that you had installed a new fuel pump, I was just saying your description sounded like the classic fuel delivery problem and listed the main pieces.

    I would look for a rebuilt throttle body, they will usually take your old one on a trade-in.

    Glad you found your problem.
     
  10. Skippy

    Skippy Member 2 Years 100 Posts

    I'm going to call this out, just in case you're unaware. Aftermarket fuel pumps have a higher than normal failure rate. It's been my personal experience that about 1 in 10 go out relatively quickly, requiring a replacement. In fact, two of the last 6 I've done had to be replaced, one in less than a week (was bad from the get go), and the second within 12 months. I strongly recommend you put a fuel pressure tester on the rail and make sure you're getting what you expect.

    Skippy
     

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