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Rough Idle, bad acceleration after spark plug change

Discussion in 'General Chevy & GM Tech Questions' started by sandyc, Oct 10, 2011.

  1. sandyc

    sandyc New Member

    I have a 1986 Chevy 454 which I just recently changed the plugs and wires on. Now, the engine idles rough. I also have almost no acceleration, especially when going uphill. It also will occasionally backfire when going uphill. After about 45 MPH, it runs perfectly. I have double checked that all the wires are connected in the correct order. I did not change the distributor cap or rotor, although I did remove it and cleaned the contacts. What could be causing these problems? The truck ran fine before. Thanks for any help!
  2. murdog94

    murdog94 New Member 1000 Posts

    I dont mean to sound mean here but are you sure you got the wires connected in the right order on the cap, and the plugs? Also is the distributor a bit loose? if so there is a chance that you bumped it off of time when you were cleaning up the cap and rotor. Also when you cleaned the cap and rotor there is a chance that the contacts were so worn that they arent making contact properly on a couple of cylinders.
    Just trying to give you a few things to help brainstorm here
  3. Chris Miller

    Chris Miller New Member

    I would definitely change the cap and rotor. See, that rotor button can get pretty worn after a while, and when you popped the cap off and put it back on, that could have squashed it.
  4. Revredneck

    Revredneck New Member

    If the distributor cap and rotor check out okay as the others have suggested, then I'd put a set of plug wires on it. 454's are notorious for being very hard on plug wires because of the heat at the plug end. Pulling the wires off the plugs often breaks the wires inside, where you can't see it. Be sure you don't go with the el-cheapo wires.
    Good Luck and God Bless
  5. dsfloyd

    dsfloyd New Member ROTM Winner 1000 Posts

    check the cap and rotor. after that what plugs did you put on there? I know the newer chevy trucks dont run as well on other plugs than ac delcos (couldnt tell you why).
  6. Rockstarrchevy81

    Rockstarrchevy81 New Member ROTM Winner 1000 Posts

    I have now got 60,000 miles on my 08 silverado when would be time for new spark plugs? I have read like you have said before the newer trucks run weird with anything than AC Delco's that came in it from the factory.
  7. dsfloyd

    dsfloyd New Member ROTM Winner 1000 Posts

    they say with the new iridiums you can go 100k. stock wires wont go super long. i could see somewhere in your mileage range replacing them. I think I did mine around 70-75k. get some AC plugs and taylor wires (or a number of other quality wire sets)
  8. Rockstarrchevy81

    Rockstarrchevy81 New Member ROTM Winner 1000 Posts

    Oh okay so some Taylor wires and Ac Delco plugs about how much would that run me? I guess ill wait until around 75,000 but it will be awhile!
  9. dsfloyd

    dsfloyd New Member ROTM Winner 1000 Posts

  10. Rockstarrchevy81

    Rockstarrchevy81 New Member ROTM Winner 1000 Posts

    Hey man does it matter about the 10.4mm or the 8.2mm?

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