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bypassing computer on 84 k5

Discussion in 'The Garage' started by 4x4k20, Jul 10, 2002.

  1. 4x4k20

    4x4k20 1/2 ton status

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    anyone done this to there truck ? i am working on one now what needs to be done ? the only thing i see it has something to do with is in the disturbator and timing it has no o2 sensor or wires to carb it runs good at idle but stumbles at part throttle
     
  2. Pure Insanity

    Pure Insanity 1/2 ton status

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    On my 86 I needed to off the computer carb, and put in a standard HEI dist. There are other incidentals like a second oil pressure sending unit, and a sec. temp sending unit I think. Lets put it this way, if it comes out of the wire harness that is to the left of the dist, as your facing the motor, it needs to be done away w/. The wires come thru the fire wall thru a round rubber boot. That is the harness that goes to the computer. Yours is an 84 so it may be different but I hope that helps.
     
  3. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Yeah, its not to hard. It should only require a different a carb. Does your distributor have a vac advance canister on it? It does, it should be fine. The extra plug on those models is only there to run a knock sensor. It'll save your butt if you have the timing wrong or bad gas. It you just have to do away with that aspect, then you can just wire those four wires together coming out of the plug and bypass it. I can't remember the exact wires to connect together, but its easy. If it doesn't have a vac advance, yank it out and put an old one in.
     
  4. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Computer? What computer? And what computer on an '84? /forums/images/icons/tongue.gif

    I thought the computer for some carbs were started in '85 or '86.
     
  5. gokartergo

    gokartergo 3/4 ton status Staff Member Moderator

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    Yep, computer for carbs was started in 86.. But the computer on a 84 is for the dist...Dan
     
  6. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    We've got an '85 parts burb with an electronic carb and no ESC. Wierd, huh?
     
  7. BlazerGuy

    BlazerGuy 3/4 ton status

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    My 84 K5 has one. It's located up under the dash, just behind the glove box.....
     
  8. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    That's the ESC module...best mod I ever did was to chuck the ESC distributor in the 'round can'.

    Rene
     
  9. 4x4k20

    4x4k20 1/2 ton status

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    it does have vacum advance which wires do i hook together? i was thinking about trying to put a 4 pin module in and tring it
     
  10. 4x4k20

    4x4k20 1/2 ton status

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    i cut the 4 wire connector and hooked all 4 wires together it wont start i also undone the red wire that runs to the bat. connnection side of the dist. and just hooked up the big red wire it still wont start where i cut the 4 wire connector it has a green wire yellow wire brown and black wire hopefully some one can remember which wires i need to hook up
     
  11. txbluethunder

    txbluethunder 1/2 ton status

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    i pulled this from a different page...maybe it will help

    ESC Stuff

    <font color="blue">I had a problem with my 86 C20 305-H engine. It could start and run fine and just suddenly die out, sometimes start right back up or take a couple hours to get. After several weeks of this nonsense (and getting very good at getting those half turn dist. cap latches off), I did some checking. There is a power feed to the spark control unit under the dash that comes off of the pink (hot) wire to the distributor. The pink wire clips into the connector for the feed, which in turn clips into the dist. cap. What had happened was the feed for the Spark Control was shorting out somewhere, killing the spark. I talked to some Chevy mechanics at my dealer about this and they told me how to bypass the spark control computer and keep the original distributor, something they claim is done quite often.
    First thing to do is unclip the spark control computer lead from the pink wire and just clip the pink wire directly to the dist. cap at the. Make sure you plug it into the cap at the BAT terminal. The second thing is to locate the 4 wire connector that feeds into the ignition module. There's a brown (D), green (C), white (B), and black (A) wire there. The letters in () are on the black clip that the wires come out of. You cut the green (C) and black (A) wires between this clip and where they go into the distributor. Then all you need to do is solder the 2 cut leads from the dist/ignition module together, i.e. the green and black ones, (make sure to tape the exposed wires) and now your HEI distributor will function just as a pre ESC model does. I did this and it has been running fine for well over a year now.

    Dan

    Note: Here is a picture made of the plug which goes to the ESC control and feeds the ignition, which Dan mentioned above. I labeled the wires which need to be cut and showed which wires are A, B, C and D.</font color>
    [​IMG]
     
  12. steve85fla

    steve85fla Registered Member

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    I have an 85 with the computer carb, best thing I did was chuck it and put in an older q-jet and vacuum hei
     
  13. 4x4k20

    4x4k20 1/2 ton status

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    thanks txbluethunder that tells me excatly what i need to do and even has a picture i am fixing to go out to the garage and try it i will let you know what happens
     
  14. 4x4k20

    4x4k20 1/2 ton status

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    i tryed it and it still wouldnt start i had to hook all 4 wires back up for it to start now what should i do? i guess ill try a regular dist.
     
  15. txbluethunder

    txbluethunder 1/2 ton status

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