I have been workin on chevys all my life!!!
I'm about to start a new mission....a TPI swap.

Motor: 1990 GTA 305 TPI
into: 87 jeep wrangler

My problem.....what wire do I need and what can I do with out???
diagram's would be awesome !!!! I bought a repair manual and the TPI swappers guide but it DOESN'T tell me what wire's I need and ones I don't. I don't dare go any father till I know what to do!!! Plus it has That VAT stuff too

 

well you need all of them unless you are removing stuff like egr, AIR, or VATS. In the case of egr and VATS you need to modify the e-prom to make it run right. I would swap the whole harness over and then if you are sure you don't need an wires you can remove them then. Better safe than just starting cutting.
John

 

I was trying to figure out if it is all mixed up with the charginf system harness too????

 

I was trying to save myself some $$$ on an aftermarket wiring harness(tight budget) and wanted to know if anybody knew of a website that did this step by step. how to separate the computer wires from the cars charging system ....etc....etc

 

I can either build you a new harness, modify a used harness (if you have one), or modify one of my used harnesses. Either way, you'll end up spending less than what a Painless harness costs. I can also test it before I send it to you. If interested, contact me privately at mike@s10wildside.com.

 

Go to this link GM-ECM drawings Best I can find anywhere. Covers all 3rd GENS