GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 2 of 2
  1. #1

    Default 2000 Jimmy, misfire question but not the typical ones

    Good afternoon everyone, thanks ahead of time for any responses.

    I picked up a 2000 Jimmy the other day with what I was told needed a new spider and intake gaskets... I got it started up but now I have the dreaded P0300!!!! I have done all of the following...

    New spider
    intake gaskets
    ac Delco dizzy, rotor and cap
    new plugs
    clean egr
    clean mac
    checked for vacuum
    checked fuel pressure... holding 60psi.

    now... I have a wet number 1 plug and backfiring..

    The only thing I haven't done, and I'm sure I I'll be told to, is check compression. So here is my question

    Lets say I check compression and find a cylinder or two that fail, what then? Assuming I'd have to pull the valve covers and check (wish I would have when I changed intake gaskets!!!) what will I be looking for? I've heard a sticking valve could also cause my problems, is this true?

    Thank you,


  2. #2


    What engine? do the compression test and check your timing first. let us know.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts