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Looking for the firewall connector wiring diag. on an 87 TBI

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 87GMCJimmy, Oct 7, 2002.

  1. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    I'm doing some electrical upgrades and was wondering if someone had this handy. I'm looking for the firewall connector pin outs with function and wire color for an 87 5.7 TBI Jimmy.

    Thanks,
    Mike
     
  2. imiceman44

    imiceman44 1 ton status

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    I know they are in the Haynes manual.
    If by this evening no one gets them for you I will scan them for you.
    IceMan
     
  3. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    Hold off for a day I might have found one. I have the 72-87 haynes manual. Needless to say the wiring diag. in it does not include the TBI. Someone suggested I pick up one for 88-xx years and should have the diag with the TBI wiring. I'm hoping that someone might have the helms manual for a 87 and willing to scan the plug definition in for me. I don't mind spending 12 bucks on a haynes manual but 120 for the helms is a little steep!

    Thanks,
    Mike
     
  4. HarryH3

    HarryH3 1 ton status Author

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    I'm not sure what you're looking for. The only "plug" at the firewall is for the fuse box. The wiring between the engine and computer don't have any intermediate connectors, and the wires just pass through the firewall using a very large rubber grommet that is glued onto the harness. Do you need to pinout from the computer? It will list the wire colors, along with what each wire goes to.
     
  5. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    I know that some of the wires go into that connector that I need. Example: fuel pump (Tan/Wht), starter, oil press, water temp...etc. Ok, let me explain what I'm trying to accomplish. I had a TPI converted engine in my 87 and pulled it out b/c it sounded like a diesel at idle. Really sucked a$$ after only 25k but I didn't trust it for long trips anymore. I got a good deal on a 99 vortec w/ 4l60e and am at the final wiring stage of putting it in. Tonight I remembered that when I put the TPI on I barrowed a friends 89 camaro Helms manual. Because the 89 camaro's had TPI and TBI I found a ton TBI wiring info. that applied to the truck. Gotta love GM on that one! I plan on emailing him tomorrow and copying the pages on the TBI. But I'm still hoping that someone might have an 87 Helm manual with the TBI pin outs. Also from earlier conversations with you- the vortec VATS isn't a simple signal as with the older TPI's. I've also been lead to believe yhat even the 96-97 wiring is different than the 98-99. So I can't replace the computer with an earlier one w/o VATS. Still researching this but I think it's true. As always thanks for the help!

    later,
    Mike
     
  6. HarryH3

    HarryH3 1 ton status Author

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    I've got the '87 Helm manual set, but I'm still not sure what pinout you want to see. Do you just need the pinout from the computer or are you looking for something else?
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    www.thirdgen.org has the '86-87 (or is it 85-86?) Camaro wiring manual already scanned in the tech section, believe its mostly complete, it doesn't have the connectors, but the pins are labeled on most of the other diagrams. Hopefully that will be of use to you, but the Camaro firewall/fuse panel plug is different than at least my '86 panel.
     
  8. Cmoe

    Cmoe 1/2 ton status

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    I am looking into putting a TPI in mine what went wrong with yours? Did you do a convert or a full motor swap with the TPI? I have a Hayns manual if you need anything give me a call. PM me and I'll give you my number.
     
  9. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    Harry - There is a big firewall connector right by the brake booster. It contains wires for head lights, wipers,power feeds for the dash, etc. It also contains wires for the dash gauges, fuel pump etc. I believe it plugs into the fuse box. These are some of the wirings that I need to interface with the vortec harness and the info I trying to find.

    Dyeager - Thanks I'll check it out, when I was installing the TPI I asked many questions over there.

    C'moe - The TPI worked great, better mpg's and TON more torque. However the bottom end of the motor was sounding like a desiel (Clacky-Clack)and getting worst quickly. I figure either bad machining, assemble or lack of proper lube to be the problem but I haven't torn down that motor yet. The motor was a stock rebuild with minor mods that I put the TPI on. Now to the new motor. I came across a 99 vortec with tanny and transfer case cheap so I decided to put it in instead. Yes I know it's a little crazy but I'm one of those people that enjoy working on the truck as much as driving it. I've asked around and I don't think anybody has put this combination in an older 4x4 yet. The kicker is the new style 6 bolt output side 4l60e but I've got that worked out. /forums/images/graemlins/smile.gif

    Thanks for the help everybody!
    Mike
     
  10. imiceman44

    imiceman44 1 ton status

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    Isn't this trans output similar to the th400?
    IceMan
     
  11. HarryH3

    HarryH3 1 ton status Author

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    I'll dig through the manuals and see what I can find for ya. /forums/images/graemlins/cool.gif

    If it was me, I'd put the TPI on top of the Vortec engine. These guys have a TPI baseplate that will work on the Vortec heads. /forums/images/graemlins/cool.gif That way you won't have to mess with rewiring again. /forums/images/graemlins/thumb.gif
     
  12. HarryH3

    HarryH3 1 ton status Author

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  13. 87GMCJimmy

    87GMCJimmy 1/2 ton status

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    Thanks! I know that I have a tendency to do things more complicated then necessary. Unfortunately I'm already well down the path of the installing the vortec and thinking of another project for the TPI system. /forums/images/graemlins/cool.gif With the wiring diag's the re-wiring of the truck is really one on the easier steps! The vortec's have a almost stand alone wiring harness from the factory. One thing I loved about the TPI vs TBI is that all the wires between the two systems that have the same function are color coded the same.

    Thanks again
    Mike
     

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