IrocZ'85

iTrader: (9)

Hey guys,

I'm nearly done with my swap, just finishing up the fuel pump relay wiring and I've got a few questions. In the addition information swap thread I found the C207 wiring for my 85. However all of these wire colors pertaining to fuel pump relay don't match what I have at all. I would like to follow pocket's diagram as shown:
[img]http://i150.photobucket.com/albums/s...uelControl.gif[/img]

1985 C207

Black Plug

PIN Color From / To (Notes)
B* Red ALDL / Fuel Relay ( V6 - TPI )
B* Org/Blk FP FUSE / Fuel Relay ( L4 )
C* Brn/Wht ECM / CE Light ( L4- V6 - TPI )
C* Wht/Grn Light Driver / ECM ( LG4 & L69 )
D* Blk/Org FP/INJ fuse / Fuel Relay ( L69 )
D* Tan/Wht Puel Relay / Fuel Pump ( V6 )
D* Lt Blue Puel Relay / Fuel Pump ( TPI )

White Plug

PIN Color From / To
H Tan/Blk ALDL / TCC-ECM
J* Ppl Starter / Fuel Relay ( L69 )
J* Org ALDL / ECM ( L4 - TPI )
K Brn ECM / VSS
L Tan/Wht Fuel Relay / Fuel Pump ( L4 - L69 )
M Blk/Wht VSS,P/N switch / Grd
N Org/Blk ECM / P/N switch
P Ppl Brake / TCC
R Ppl/Wht Crank Fuse / Cold Start-ECM ( V6-L4 )


Now my 85 is a factory TPI car, so i know i highlited some of the L4 and V6 lines in that list...but i just wanted to illustrate that NONE of those configurations are what I have....so I'm not sure really what wires I should be looking for. From what I can gather, there is nothing on my factory C100 that controls FP relay either, so I didn't bother with that.

When I'm under the car and find the weather pack connector all the way by the fuel pump itself, I have a black, pink, brown/white wires coming from it and then it goes into the body where I cannot trace it. Does this sound right? Does anyone know where I should be splicing into for the FP relay wires, or is something wrong with my factory wire colors? What I can do later is write out all the colors on my c207 that I DO have if that helps.

thanks!

TEDSgrad

iTrader: (4)

https://www.thirdgen.org/forums/ltx-...formation.html

Post #19

IrocZ'85

iTrader: (9)

hmmm this is what I had checked and i reference it up in my post, but like I mentioned, my wiring does not match this

cam-

Suit yourself but I dont use the factory harness for fuel pump control its not up to snuff IMO. I run the fuel pump relay command circuit from the LSx PCM/ECM to a new relay, ground the other side of the relay. Then power in/out with a big fat 10 awg feed straight to the fuel pump. This is known as the "hotwire" mod so theres no oil pressure switch and the wiring is strong enough to support high hp without issue at all. Running through your stock 3rd gen fuel pump circuit is less than ideal IMO.

Pocket

iTrader: (24)

I disagree
Stock pump wiring is 16ga, and more than ample for most pumps including the super popular walbro 255

I do prefer to cut out the oil pressure switch and just run a PCM controlled relay directly to the pump

To the OP,
Your pump wire will be in the C207. Its easy to spot because its the largest gauge and tan/wht. It should be pin D

cam-

Maybe when its fresh. But after 20 years most of the stock wires are blackened with corrosion and my attitude is always overkill. For the 50 cents more it costs to run a beefier wire its money well spent IMO. Plus theres been a LOT of testing on factory wiring over at tech and there was quite a few surprises about erratic power supplies to the fuel pump in stock applications. Im not saying it doesnt work for some or most maybe it does? But why not make a good thing better? Isnt that what we're all trying to do here?

Its this exact mentality in all my builds and why no one yet has broken one of my diffs. Good enough just isnt good for me. I want the best solutions everytime

Pocket

iTrader: (24)

I see where you're coming from

IrocZ'85

iTrader: (9)

thanks pocket! I did end up using D tan/wht, it was thickest, as the relay to pump wire. Also, should i be using "B* Red ALDL / Fuel Relay ( V6 - TPI )" for anything or just conect my pcm to the green/white wire as per your diagram? I agree with the comments made and i will not be connecting to the E5 C100 oil pres. switch either. Lastly does the fuel pump relay RED wire not go anywhere? The diagram shows it just dead end, should i remove the pin in the relay connector itself?

Thanks for all the help guys! its almost able to run!

IrocZ'85

iTrader: (9)

^^ bumpity bump

Pocket

iTrader: (24)

Red is prime for diagnostics only. I remove them because Id prefer to bridge the relay socket to test vs rely on the relay Im testing to work