slow2000z28

my friend and i are trying to install a ?91? 5.0 TPI engine into a 86 p/u and transforming it into a rock crawler. we have the harness and the computer. we are getting spark and it will run on carb cleaner. we can even get the cold start inj. to spray, but we cannot get it to spary normally. he has a high pressure inline pump on it now. weve pulled the upper manifold plenum and fuel rail in order to watch the inj. spray, but we are not seeing anything. im not too farmiliar with TPI engines and im not sure what controls the inj spray timing. weve tripple checked the grounds because im pretty positive that the ecm grounds the inj. to makr them spray. thanx for the help in advance.

Formula350

iTrader: (3)

Well that is for SURE not a 91 TPI if it has the cold start 9th injector. They ended that in 88 along with Mass Air Flow. 89-92 were speed density and had no MAF. If you're mixing an 88 setup with an 89+ ECM (or even vice versa I I'm sure) you are most likely going to run into problems. I honestly wouldn't be surprised at all if having the wrong year ECM is your issue. HOWEVER the ECM may be the same between 85-91 but the EPROMs change, they do that sometimes. It's been a couple years since I had my 91 TPI Firebird, but I think my ECM was a 727 model (the last 3 digits on it).

Hopefully this site can help you out. And GL.
http://chevythunder.com/

EDIT: A quick glance at that link shows the pre-90 ECMs to be different. I MAY be mixing up my years but I'm 90% sure MAF TPI engines with the cold start injector were 85-88 and 89-92 were w/o and Speed Density. But I could be wrong and that's 85-89 and 90-92 for the year spans.