I am attempting to swap a CCC carbureted engine into an 87 Formula that originally had an L-98. My question is: Can I swap in an engine harness from an 84 L-69 car into the bulkhead behind the brake booster or are the pin counts different? i want to keep the computer setup for gas mileage etc but would it be worth the hassle? What type of problems will i encounter? TIA.

 

I would say yes. But I did it with a V6, putting a more complicated harness in place of a non-ecm harness (i'm in Canada, most early f-body came without here).

I did the opposite as you. I would try to keep to it FI, but you must be up to something.

I take it your trying to keep the 87 interior harness's in there just attaching the engine harness to the bulkhead. That should work, but in my situation, I couldn't do that, that would have been way too easy.

The 87 has a harness that "wraps" around the dash and firewall through the bulkhead as well as the pass side frame rail to the computer and on to the fuse fuse panel. You probably know that. Does your 84 do this? my 83 harness didn't. No ECM, no emission stuff FACTORY. I saved that harness BTW. And as an added to bonus the 83 had the holes in the frame to accept it

Look at how the wiper motor connections are, In my situation I am trying to use an '83 wiper motor (firewall issues, it changed in 84). I am still trying to fiquire that one out, it's my last peice of the puzzle. A wiper wiring diagram for a 82,83 firebird wiper motor and 87 firebird wiper motor (both fedral) would be so helpfull right now, mine is different from anything posted or written about on this site. Or a wiper wiring digram for a full-size chev, my dads 87 Caprice has the same motor, mechanical pump (big ugly thing) set-up as the 83 firebird, just different wire colors. I'll be posting that question on here next.

I need to know what each wire does, I have 6 wires on two connectors on my harness and 6 wires on my motor, except my 83 motor used to pump fluid to the hatch, the 87 donor didn't have that option.

The headlight wiring is different (82-84) harness will work with a newer engine harness easy enough, the new one has few more wires. My 87 headlight harness was destroyed in that cars accident. I'm not sure if I would have tried to use it anyway.

fuel pump?

Taillights connectors are different, I used the 87 taillights since i had the donor car.

P/W, P/L, AC, Cruise (steering coulm connection), I imagine you thought of that already. I had to short out an A/C connector on my harness to stop constant operation of the fan (my 83 has no A/C). Incidentally I had to buy a power steering bracket from a non-ac engine to get the belt to go on.

I'm not sure if any of this is relevant to you, but something to think about.


See ya

 

We seem to have a lot of the same problems in common. if you ever have questions, drop me an e-mail at DunawayD@twmi.rr.com and i'll try to help you out. Maybe you could do the same for me.