Loss of power :

Discussion in 'Shop Talk' started by dogo, May 23, 2006.

  1. dogo

    dogo Well-Known Member

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    I need some suggestions on where to look . First i have a Z-71 which comes with a towing package . Its 1998 extended cap . Now I bought this truck with 17,000 miles but had a 5 yr. 85.000 warty. the rear end has been replaced, also a New Trans. all factory . I put dual tail pipes on it took the mufflers off put glass packs on it . the problem begins when towing a boat was the first time I notice the loss of power and the engine service light would come on .. to make the story short . I had a dealer to tune it up, you know connected to to the machine and all told them what and how it was acting . about 600.00 dollars worth but still the problem was not solved . They came up with all sorts of things but the real problem . They wanted me to go to house hung up my trailer and pull it up a hill to show them what it was doing ? Can you believe that ? I knew right then these people were trying to blow smoke up my a--. I got tired of messing with them summer was over and I wasn't pulling a bout or anything so I forgot about it, big mistake. Its my sons truck I bought it for him for Grad. but still the dealer should have qualified technicians to perform at that price . Anyway when pulling a trailer it loses its power and the service light comes on as before . I could have kelp the 600. at least I would have money for tow . Have any of you guys have an idea what the problem could be ?
     
  2. moopups

    moopups In Remembrance

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    This problem could be one of a great many thing; in older vehicles I would suggest you seek a vacuum leak - spray WD-40 on the connections while running, a speed up would indicate a vacuum leak. Secondly maybe a timing related mis setting, the power loss while under load indicates this; fuel, filters can also be the cause. Find an old time 'seat of the pants' mechanic with a lot of experience.
     

  3. dogo

    dogo Well-Known Member

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    Moo I was thinking somewhat on that line " fuel pump not filter . I do remember the fuel pump was kinda loud , but quited down a lot when they did replace the filter during the tune up . I ask them to check the pressure and they said it was a little low . I'm thinking when the engine is demanding more fuel for power, thats when the pump fails the test . Are there a test load you could put on the pump ? what do you think ?
     
  4. fixer1958

    fixer1958 None of the Above

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    I'd have the fuel pressure checked because I believe that is a Vortec engine and 5psi off can really put a dent in performance especially with a load on it.
    Check the filter also because you can still have pressure but no volume.
     
  5. mohillbilly

    mohillbilly Well-Known Member

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    Scrap the chevy! HEHEHEEHE!!!! just kiddin!


    I would also look to the fuel system. Filter first and then pump. What really amazes me is that with that few of miles, the tranny and rear end has been replaced, sounds like it was really run/beat hard in its early years.

    Maybe get a code reader for it, think you can get them for around 75 bucks, do your own diagnosis, hell, some of the mechanics out there only know what the computer tells them, then change the parts to make it run, they have no REAL chlue as to why an engine does what it does in a abenormal situation. jusyt a suggestion, and I am not slamming ALL mechanics!