I'm having trouble getting my new L98 to run after the swap and am wondering if I have some compatability issues that need to be resolved. The inake, plenum, runners and rails are '86, the harness is an '86 (maybe 85) and I have an '88 and an '86 ECM. The car is a '90. Do you guys see any conflicting parts here? In case you're wondering the car starts and runs for a second then shuts itself off. Any ideas?

 

You have a MAF sensor, right? I'd use the 88 ecm/chip since it has cold start enrichment, so the cold start sensor will just plug a hole(if you use it). One less thing to worry about.

 

How about the throttle body? The
man interchange problem is with the
TB/plenun/runner issues and the idle
air passages and cold start injector..

(A '90 TB will not run right on an '86 plenum/runners)

mike

 

Bingo.

My Guess is that is the problem.

 

'88 TB and plenum. I have an '86 TB and plenum too, should I try that?

 

As long as you have got the Cold Start Injector Vacancy plugged on the Base runners plenum ect (wich would be pretty obvious if you didnt ) and You have a Matching plenum/TB setup, then I don't think this is your problem.

Did you use the right gasket on the TB/Plenum? I forget if the 88 Setup is the early or late one.

 

CSI Vacancy? I have the cold start injector installed. I'll check the TB gasket. Thanx for the ideas!

 

Now that i think about it, I once used the late TB gasket on a early TB/plenum and it did the exact same thing. It blocked the IAC passage.

It would fire up and die.

I do belive 88 uses the old style TB, too so you might be in luck.

 

Hopefully! I picked up a gasket today with the IAC passage. I'm gonna throw it on tonight and see what happens. Thanx guys