All right where to begin. I recently just bought an 89 rex, but it had an s4 motor in it. They some how got the car to run with the s5 harness and ecu. Unfortunatly though the car only runs on about 1/3 throttle and then it dies out. I was trouble shooting it, but because of it having the wrong harness and ecu it is a nightmare. Now the car did come with an s4 harness and I want to splice this harness into the ecu. I was wondering if anyone new a link to any wiring diagrams for this. Or if they have any idea how they managed to get this motor to run. The car did come with the s5 motor, but it doesn't hold compression and the s4 came with all the parts to turbo it. Just looking for some ideas on what to do and where to start

 

you're gonna have to dig through both FSM's to find the pin outs. have fun.

 

arghh that is what I was afraid of...think it would be worth it just to convert the whole thing over to s4 and get the ecu and interior harness. Or do the whole cut, match, and splice route. I have an s5 motor that is street ported, but it doesn't hold compression and I don't know what's wrong with it.

 

if you want to go that route i have all wiring besides the engine wire harness from an s4.

 

yea that would be perfect cuz like I said I have the s4 engine harness. Are you looking to get rid of them and if so how much???