Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Sputtering at low speeds

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by kburnett, Apr 10, 2003.

  1. kburnett

    kburnett Registered Member

    Joined:
    Mar 15, 2003
    Posts:
    7
    Likes Received:
    0
    Location:
    DFW, Texas
    I just replaced the engine in my 71' Blazer and the thing runs like a top at idle and high speeds. However, when I am in neighborhoods driving slow or accerlerating slowly it sputters and misses, not real bad but noticeable to me. I have the electronic ignition from a 75' or later and the spark plugs to match at a .060 gap. I have also tried plugs from a 71' with a .035 gap. It also has a new edelbrock intake and carb. The plugs all look good carmel/tan in color and the timing is set at 12BTDC. I have changed the timing from 8BTDC all the way down to 16BTDC with no affect to the sputtering. I have changed out the distributor with a spare and changed out the cap and rotor and plug wires when I replaced the engine. I can't figure this thing out and the only recommendation that friends have given me is "Drive it like a race car and you won't have a problem". Do you have any ideas??

    thanks
    kent
     
  2. BRN78BLAZER

    BRN78BLAZER 1/2 ton status

    Joined:
    Feb 5, 2003
    Posts:
    133
    Likes Received:
    0
    Location:
    Stoney Creek Ontario, Canada
    maybe the carb needs adjusting, could be too rich or something? It sounds like carb related to me but I'm not sure.
     
  3. ccox7

    ccox7 Registered Member

    Joined:
    Jul 24, 2002
    Posts:
    69
    Likes Received:
    0
    Location:
    Bayou State
    Sounds like an accelerator pump problem, when you are coming off idle you need a good squirt of fuel to keep the thing from falling on its face.Float level could be off a little too. Probably something simple, try to look down the carb with engine off and work the throttle by hand with a flashlight, see if fuel is being squirted with a good stream into the venturis.even though it is a new carb. something could still be defective in it.I have also seen the pick-up coil cause this to, a little break in the wire and when you try to accelerate, ported vacuum advances the timing.This in turn moves the pick-up coil inside the distributor.Could have a wire inside scraping against metal causing a glitch.
     

Share This Page