Ok. So I am trying to get my Cutlass running.  3 yrs ago I started the 2.8 auto to 3.1 5spd turbo swap and ran into some issues with it running, got busy with other things and the cutlass sat for 3 yrs.  Fastforward, now I am ready to drive it again.

I am running the 88 wiring harnesss converted to 5spd. 

The car WILL run with the 88 computer with stock 2.8 auto chip.  Albeit idles around 2000 and is pig rich, it runs!

When I put in the 90 TGP ECM and a chip from Adam it will roll over, start and then immediatley die.   I am wondering if somebody may have some ideas.


I am thinking it MAY be due to the 88 originally running a MAF sensor and now I am not running it due to the TGP?  Or was the 88 wiring that different than the TGP?  I don't understand because as best I can tell the harnesses should be the same!

Would anybody have any ideas?  Thanks in advance!

KYle 

I would get the engine running with the 2.8 ecu, unplug the IAC and hook up the t3.1 ecu. I have a problem with my car running when it is first started, it'll die after a minute or so. I keep my IAC unplugged all of the time. I have to stay on the throttle to keep it running for the first minute or so but after that it runs fine. Try to get it warm and see if it'll keep running on its own.

What map sensor are you using? Any error codes?

i had major problems with mine for a few years. super high idle, rev up between shifts. turns out i had the MAT sensor wired wrong. all those years for 2 stupid wires....

i had that air flow sensor i think you're talking about in the air box originally with the 2.8, it now just sits there unplugged, no issues

and i had definitely tried messing with the iac quite a few times in my confusion as well. computer and chip swaps too. the MAT sensor wiring is unique, with its own 2 pin connection off the main harness

Thanks for the tips guys...I have given up for now on getting this running.  I have put it in storage for the time being.  Will re-visit when I have the time do work on it!

You definitely need scans of both the '88 computer pinout and the TGP to be sure. Especially having the MAF and just being the first model year, some of it is bound to be different. When I did my 5 speed swap for instance, I know the AIR valve and wastegate solenoid used the same pin on the ECM on different cars. Didn't matter since I didn't have an AIR valve, but that's just one example.