Hello, I'm new to engines, but I'm learning. I am rebuilding my TPI engine, and now that I'm removing from the car I'm noticing my whole wiring system is shot (guy who sold it to me had mice living under the fuel rails) I know I need a fuel pressure adjuster for the in-tank pump, distributor, and torque converter thing. I was wondering if I can ditch the whole wiring harness or if any of it is needed (maybe for that fuel pump). Also, what about speedometer cables,and all of that stuff (sensors that are screwed into the block,vacuums, etc). I am trying to find a detailed step-by-step process but can't find one. I know there one on here in the tech articles but it's not super detailed. Any help will be useful for me. Thank you

im toyin the same thing,but was wondering about some of that stuff to, but like the vats,electric speedo little things like that, mind you mine is a 90 ta

i have a good tpi harness for cheap and everything else.

Everything will work as before. You just need the wires from the harness on the driver side (from the fuse panel) - the pass side wiring harness is all the computer controlled stuff, which you won't have anymore if you go carb.

Wrong. Depending on the year of the car, you will still need that harness for the wiper motor, washer fluid pump, and a bunch of other stuff. Best thing to do is cut out all the TPI stuff, like sensors and injector plugs.

You need to figure out where everythings at first. Speedo if it isn't mechanical, tach wires, temp sensor wires, oil pressure wires, and all kinds of other stuff. Do it right or don't do it at all, the PO of my car didn't do it right and now I'm stuck trying to figure out how to get all my gauges to work.

I admit, I have no clue on the TPI system. But I've read on hundreds of TPI to carb swap threads here that the pass side harness was unneccessary after the swap - same as TBI - guess after seeing that so amny times on here, I assumed it was true - I never read any threads where someone yanked it out and had something not function - but I was still assuming.

Washer fluid pump, wiper motor, front lights, oil pressure sensors and sender, water temp sensors and sender, starter and alternator/charging system wires, distributor wires, and all other basic functions have always been on the driver side harness of every 3rd gen I've ever seen, but again I haven't seen them all.

No biggie, just wanted to make sure the original poster had good info is all. I just did the swap, and I can say for sure on my 88 GTA with the digi dash, that the oil psi sending unit, water temp sending unit, all starter/charging wiring, dist wiring, and wiper/washer wiring were all part of the harness that comes through the pass. side.

That harness, however, plugs into the junction block on the driver's side firewall. So maybe that's what you were thinking of.

But all in all, best thing to do if the wiring in the car is good now, is to do the swap and just cut out the TPI wires that will no longer be used, and remove the ECM. That way, you shouldn't lose functionality of the stuff you need to drive the car but can lose all the TPI stuff you don't need anymore.

That, and it's a whole lot easier than pulling/swapping an engine wiring harness, trust me, that isn't a whole lot of fun...

Ahhhh - GTA ... that's a whole new ballgame in itself I believe - Alot of the 'bird stuff is backwards, which I always though was weird that they'd go to the trouble instead of having a standard wiring harness for all 3rd gens. Isn't your battery on the driver side?