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For mechanics only ?

Discussion in 'Off Topic Threads' started by djpk69, Jan 1, 2011.

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  1. djpk69

    djpk69 TS Member

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    Sirs,
    My father is 87 years old. We took away his car 3 weeks ago. I want to buy it. It's a 1995 Pontiac Bonneville. It has ONLY 44,000 miles on it. The problem: when driving at 60 MPH.....the car misses. It is intermitent. Only, I would say every 15 miles or so(we drove it 120 miles last night with our fingers crossed) I changed the plugs. I added gas additives for fuel/injectors.......He only drove 78 miles last year and 500 since 2007. Any thoughts ????????
     
  2. djpk69

    djpk69 TS Member

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    P.S my next thought is SEAFOAM.....then diagnostics.........witch are hard to find for a "1995"
     
  3. Dark Horse

    Dark Horse Member

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    Think about changing out the spark plug wires. After 16 years the wires/insulation is almost certain to be breaking down. IMHO It is one of the most overlooked problem on those older engines

    It takes more voltage to fire a plug at highway speeds than at idle.

    I had a broken valve spring that caused a similar miss at highway speeds, but go with the easy fix first.

    Mark
     
  4. Schmidt Racing

    Schmidt Racing TS Member

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    I think Dark Horse hit it right on the head. Buy a good set of plug wires and change the fuel filter.
    Good Luck, Dick
     
  5. maclellan1911

    maclellan1911 TS Member

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    sitting ageing cars can be as bad as driven hard cars. Moister has a chance to sink in. Also be warry of the plastic intake system the GM coolant was/is known to really decay the plastic especially around where the EGR gas port is.
     
  6. Pull & Mark

    Pull & Mark Well-Known Member

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    I'm with S Racing above!!! You need to change the oil and filter/ check air filter as well. Break-em all. Jeff
     
  7. Shooting Jack

    Shooting Jack Active Member

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    One of the most common problems with intermittent misses was due to a bad PCV valve. The wrong PCV valve for that model will also cause it to skip and suck oil. The other thing that I would do was mentioned above and that is treat fuel with Seafoam. Moisture in the fuel can cause intermittent miss with the injectors. Jackie B.
     
  8. cubancigar2000

    cubancigar2000 Well-Known Member

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    All the above are good suggestions. No matter what you find I would do the Seafoam treatment in both the fuel and the oil.AS much as it sat there has to be sludge in the oil and the Seafoam is simply awesome stuff.
     
  9. Shoemaker

    Shoemaker Member

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    You state that the car has only been driven for 78 miles in the last year. You said that you used sea foam, but did not comment about adding new gas. If the gas is a year old, it could very well be the problem as gas that old does not burn well. This could answer the idle okay but rough at high speed. Seafoam although good stuff and would recommend will not make the old gas burn better. Run a tank of new gas in it and see if it helps. If not go with the recommendations above they are good ones.
     
  10. joe kuhn

    joe kuhn Furry Lives Matter TS Supporters

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    And let us know what works in the end.
     
  11. ljunatic

    ljunatic Member

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    3.8L GM V6's are notorious for misfiring due to bad coil packs and spark plug wires. They will miss under load at light throttle, usually going up a hill in 4th gear with the Torque converter clutch applied.
     
  12. tumbleweed

    tumbleweed Member

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    <a href="http://s75.photobucket.com/albums/i296/3miles/?action=view&current=fuelpressure.jpg" target="_blank"> fuelpressure.jpg </a>

    I would also recommend checking the fuel pressure regulator. (shown in picture) It is located on the fuel rail toward the front of the engine and it has a vacuum hose running to it. Remove the vacuum hose and if you smell raw gasoline, it needs to be replaced. It is held in place by a small internal snap ring. They run about $40-$50.

    http://pontiacbonnevilleclub.com/forum/index.php
     
  13. djpk69

    djpk69 TS Member

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    Thanks guys for all the suggestions. I haven't had too much time this week and I don't NEED to use this car. Plus, my father is saying that he doesn't want to sell it...although he WILL never drive again. I'm going to just wait that one out. Last weekend, I tried sea foam....crankcase, gas tank, and direct thru a vacumn line. It seemed to work.......but it didn't. I also replaced the PCV valve. My brother put new " higher octane" gas in 3 weeks ago.....along with dry gas and injector cleaner.My next step will be fuel filter and plug wires. Autozone seems to lean towards the ICM (ignition control module). That will be the step to follow.The check engine light is never on though ?? They say I can take the old ICM in to bench test it. Sounds easy......although finding the PCV on that V6 had me flustered for an hour (no vacumn line hooked up to it...hidden under a black plastic cap). I did lots of tune ups 25 years ago.....but not since this electronic stuff and "shoe horned" engines came out. All for the GOOD I guess though !!Will update later !
     
  14. djpk69

    djpk69 TS Member

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    P.S. TUMBLEWEED.......I will check your suggestion.........and that pontiacbonnevilleclub site. It is a Sweet riding car ! And I love the cassette player as I have about 200 old cassettes !
     
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