well i swaped my 2.8 mpi for a 91 305tpi. I got the harness and ecm with it. Swaped it over and now when i turn my key on, fuel pump primes, but car will not turn over. headlights wont work. horn wont work. radio, blower, and hatch release wont work. I do have 12 volts to injectors, 12 volts to tps, and 12 volts to the larger diameter of the red wires at the ignition coil. when I turn key on the only dash light that lights up is the C.E.L. When i turn key to the start position, the temp guage pegs hot and the brake light turns on on the dash. I feel like its got to be a ground but Im almost positive they're all hooked up. 2 on the rear drivers and passenger side heads. Main ground from head to firewall. 2 grounds over by battery. Battery to Engine block. I am not electically challenged usually so sugestions can be quite complex and I can follow along. I dont know how I can get something screwed up this bad. Thanks guys for your help!!

 

In an effort to be more thorough, I want to add some more info and more questions.

I swapped in an engine, harness, and ecm from a 91 z28. (305 tpi map system) into a 89 rs with a 2.8mpfi v6. On my 89, I noticed that the wiper motor control harness plug (big wide one) is part of the engine harness. On the 91, I noticed that the connector is part of the body harness. Does this mean that the pin designations are different at the connections on the drivers side firewall by brake booster? Do I need to also swap body harness and fuse block under drivers side dash? I was under the impression that this was pretty much plug and play. Obviously not. If anyone has any close up pictures of the wiring and routing under the hood of their 91-92 Camaro, I would really appreciate being able to look at it. Does anyone also have the pin designations of the connectors at the drivers side firewall connector. Any help is GREATLY appreciated!! Thanks guys!!

 

sounds like ur on the right tack, pinnouts are most likely diff on the bulkhead connectors.

http://www.austinthirdgen.org/index.php?pid=19

 

Thanks for the info. After tonights diagnosis I have realized the bulk head connections are pinned differently. Also wiper motor and washer fluid are controlled on body harness in 91, and in the engine harness in 89. I believe I am gonna pick up a new body harness rather than hack or splice my existing one up. Can anyone tell me pin locations for the fuse block side of the bulkhead connector? I will have to move the wires around to match with the new 91 harnesses. I really appreciate the help guys. Im entering the area of being over my head. How do I remove the pins from the connector on the fire wall below drivers side dash? Need a special tool?

 

I swapped my 89 IROC MAF to a 91-92 Speed Density and had to change all the harnesses except for the A/C harness and door lock/window harness. You will need the dash harness, rear body harness that plugs in by the back seat, the front light harness and of course engine and ecm harness. You will need a knock sensor as well and it will help to get a chip to delete the vats or you will have to get the little black box, column and key from the donor car or the vats system will lock you out. You will have to make brackets for the 90-92 dash and gauges as well since your 89 and older gauges and dash will not work and lets not forget the air bag system that you will have to hook up including the brackets at the nose of the car and one at the heater vent and the last one at the power window switch location of the console. You will be busy. BEEN THERE AND DONE ALLLLL THAT...

 

Uh..im positive the air bag system is separate from the engine and ecm wiring. I should be able to go without that. I should be able to run my mechanical speeding if I buy that little black box. And from what I was told, since im keeping my ignition switch and module, the security should be fine. Maybe not. How do I bypass vats if needed. I know it can be done. Can anyone vouch for this? Its the first I've heard of it being this complex. I thought I could move some pins around in the c100 connector and bypass a few things and run it. Is it really this complex? Thanks guys!

 

If you will look at the 730 ECM the whole harness plugs in and the part that is yellow is air bag. I didn't know if it would work without it so I added it just in case. I had the air bag column with the right key to work with the rest of the harness and ECM so it saved me time and trouble. I welded the brackets in the car and added the air bag sensors and harness which are fully functional by the way and the car started and ran. I don't know what you will do about gauges since you will have to change dash harness (or I did) and your 89 and older gauges will not work. I did mine as a plug and play not going the pin route and I actually used 91 and 92 wiring. 90 on is different in most ways than 89 and older except for A/C and locks/windows. The cabin harness in my 89 would not work with the 91 harness so I had to get the rear body harness as well including the fuel pump and lights. I had mine running with vats and everything functional and I eventually got a chip deleting vats, smog, etc. Make no mistake it took me a month of finding a harness and learning that it would not plug into an 89 and older harness. you will need 90 and newer (speed density) or you will have compatability problems. I did this in 1999 so it has been a while. I have since added a ford 9, 4 inch mufflex exhaust, stealth ram and brodix track1 heads. The car really has been through a massive transformation in every way to start off as a 89 350 fully loaded IROC. It even had the bose system. Look at your dash first and see if you can find someone to make your gauges work and if not I will try and take pictures of the brackets I made to fit a 90-92 dash carrier. I think you will have to change to 90-92 because I tried everything to keep my factory gauges and dash but eventually had to change. It is a MASSIVE UNDERTAKING but it has been done before because I have done it.