Need some help, can anybody point me in the right direction?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by midwest wheeler, Mar 7, 2004.

  1. midwest wheeler

    midwest wheeler Registered Member

    Nov 14, 2001
    Likes Received:
    I am having some trouble with my K5 after taking off and rebuilding the Q-jet and I don't know where to go from here. It is an 84 K5 with a 454 and 350 auto tranny.

    The problem is that it won't accelerate past around 35 mph unless you let off the gas and let the tranny shift into 3rd. It runs fine at idle and up to around 35 mph with no dead spot or surging, just good, hard acceleration.
    But when I get up to around the 35 mph mark and it is going to shift into 3rd gear it starts to cut off/surge like it is running out of fuel or spark, and won't shift unless I let off the gas, then the problem goes away and I can floor it in 3rd gear with good acceleration. I can put it in 1st gear and hold 4000 RPM's while driving no problem. I am starting to think it is transmission related.

    I know it is hard to troubleshoot over the internet but can anybody give me some ideas? /forums/images/graemlins/dunno.gif

    Thank you
  2. doctor4x4

    doctor4x4 1/2 ton status

    Jan 22, 2002
    Likes Received:
    Los Angeles
    well ill take a stab at it
    might be vacum related or kick down cable related
    did ya change either of these 2 when reinstaling the carb ??
    and vacum might be modulater at the tranny
    messing up on ya some are adjustable and the vacum might be sucking it wrong or unevenly
    outher then that ???
    good luck and welcome :-)

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