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Sluggish at light throttle

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by Bogel, Feb 24, 2014.

  1. Bogel

    Bogel New Member

    1990 Suburban 3/4 ton 350, th400

    So I have a problem with a stutter or a backfire (Cannot tell while driving).

    So far I have noticed,

    -Miss/backfire/stutter under load does this randomly.
    -TERRIBLE gas mileage
    -Rough idle sometimes?
    -Slight miss at idle
    -sorta hard starts, what I mean is it takes about 4 seconds of cranking to start...Goes away when warm.
    -revs increase when when pressing the brake pedal
    -Exhaust does not smell normal (I cant describe it, but its not right)
    -SES came on and off a couple times when raining, has not come on since.

    There is also more I have noticed and just can't remember off the top of my head.

    What I have done to test this,

    I have searched for loose connections, noticed at the CTS there is a torn wire right before the connector. The wires are still intact, break is so close to the connector I have to go to junkyard to grab a new one. Not sure if it is causing the problems.

    I have also tried searching for vaccum leaks with my propane torch and hose, did not work...Going to pick up some spray to look more in depth.

    I was curious is there a way to test the CTS lines after I get a junkyard connector to replace my bad one?

    Basically I think my problem is one of three things or all of them:

    -Vaccum leak
    -CTS Sensor
    -Fuel Pump

    Am I in the ballpark here? Open to any suggestions, I am waiting on my new parts for the brake lights and just kind off puttering around.
  2. Conlan Rose

    Conlan Rose Super Moderator 1000 Posts 100 Posts

    My guess is fuel issue with your listed problems. They all can be traced to the fuel system.

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