CODE 42 ?!?!?!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by greg83k5, Feb 4, 2002.

  1. greg83k5

    greg83k5 1/2 ton status

    Nov 2, 2001
    Likes Received:
    space sity houston, texas
    i posted awhile back about a friend that had a problem with his 91 k5 stumbling and surging, and generally running very weak, and throwing the CE light. he could clear the light and the stumble by turning the ignition off, then restarting.....

    most of my replies got me ready to diagnose problem as bad fuel pump, or filter.....

    he gets code 42 ( EST, electronic spark timing ) out of the diagnostic.....

    any ideas? is the ecm possibly advancing timing too far, or squirrelly all over the place??

    would this cause a stumble and loss of power thru the whole rev range? ( i could see down low or up high if it wasn't advancing, or advanced too early, but not all over!! )

    * keep the greasy side down *
  2. Thunder

    Thunder 3/4 ton status

    Jul 20, 2000
    Likes Received:
    Northeast Nevada
    Sounds like a bad magnetic pickup coil in the dist. That will give a code 42 and cause stumbling, surging ect..... You have to pull the distributor to change it. They cost about $30.00
    The ign module (little black box)in the dist may also be bad. you can take it out and down to a parts store like Napa. They will check it for free.

    <font color=blue>Nevada... Where the pavement ends and the west begins<P ID="edit"><FONT class="small">Edited by Thunder on 02/04/02 09:47 PM.</FONT></P>
  3. rampage

    rampage 1/2 ton status

    Mar 20, 2001
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    Humboldt/Pacifica, CA
    Again, as I posted in your original "Solve this Problem" thread, change your fuel filter. When you cross reference the code to what the trouble may be in your service manual, they only tell you what sensor is throwing the code, not the actual problem. The problem still sounds like your engine is starving for fuel so the cheapest, easiest thing to do (and most likely the problem) is replace the filter. Just did mine this weekend in about 15 mins, with an accidental gas bath *L*

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