1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

emission fail

Discussion in 'Chevy Trucks' started by medrano75, Feb 7, 2007.

  1. medrano75

    medrano75 Junior Member
    Messages: 2

    i have an 84 silverado with 5.7liter 350 4bbl today i ran it through emissions in az. everthing passed with flying colors except the carbon monoxide test, the stanard is 48.00 my was 54.66 my question is does anyone know of a quick fix to get my truck to pass
  2. midnightsun13

    midnightsun13 Junior Member
    Messages: 25

    when i went through emissions i had my y pipe unhooked from my manifolds....soon as i got there about 5 guys jumped under the truck.....didnt see anything so they ran the test....it passed since there was almost nothing at all comming out of the pipe.......test guy handed me the paper and goes "you passed....we thought it might have had a hole in it" i looked at him and said "if you only knew" and drove off.....:bluebounc prsport
  3. dodgeguy99

    dodgeguy99 Senior Member
    from mn
    Messages: 272

    how did he not see that the pipes where unhooked

    REAPER 2000 Club Member
    from 60050
    Messages: 2,230

    Not sure how many tries they give you before they revoke your plate but you can try these tips.

    Change your distributor cap and rotor, PCV valve. New spark plugs and if the wires show any wear replace them as well. When I had a 82 GMC I also replaced the coil with a Accel high performance type.

    Air filter and oil filter change also.

    That will get it to burn the gas the best it is going to.

    What I really believe it is tho is your carb adjustment. You may have to find a good carb guy(hard to find these days) and get your carb tuned properly.

    I would try the basic tune up 1st and go from there.(plugs/cap-rotor/filters.)

    Before you take it in take it get about 20 bucks worth of some premimum gas and then get on the highway and get it up to the fastest speed you feel safe driving and run it open like that for at least 5 minuets after it is at the proper running temp. This will blow the carbon out I have even done this with a fuel additive added before and after the tune-up.

    If it wont pass after all of that you probably need to do a engine flush with gunk or diesel and re-tune it and hope for the best.

    The main thing is after the new parts are installed is to make sure that carb is tuned properly.

    Good luck I know it is a pain for something most people think is a waste and or a scam when you have semi's spewing black soot right past the place you get the test.
    Last edited: Feb 8, 2007