k, i thought i hit paydirt getting an entire virgin tpi setup for $150, but then i find out that 85 ecms are crap. So i bought an 87 ecm and harness. Now i got all the sensors with the 85, and i got just wiring and the ecm with the 87. Do i need the MAF piggyback comp thing for the 87? what additional sensors am i gonna need? what else do i need to know? will the 87 ecm work with the underdash wiring harness in my 85? there aren't any changes to the aldl connector harness are there?

 

O-Gene,

This may give you a little help:

http://www.ece.udel.edu/~davis/z28/ecm_swap/

 

I did the swap last year. Like you, I elected to replace the whole harness instead of repinning it. I could just see myself under my dash board with a solder iron and a DMM for 6 months trying to figure out why my car wouldn't run.

So in order to minimize down time, I changed the harness. It's a super easy swap. Everything plugs in except for the distributer. The 87 cars used a small cap distributer with a remote coil, where the 85 has the large cap distributer. BUT, you'll find that the 4 wires in that part of the harness are all the same color and correspond to the same function. You can buy an adapter, build an adapter, or just replace the plug on the harness with the correct one. In my case I swapped to a small-cap distributer, so I had to modify my chassis harness instead.

So anyway... you'll have a spare plug for the 2nd coolant fan that you don't have. Just wire tie it out of the way. I also had an extra wire in the harness that was supposed to attach to my starter bolt. I just cut the wire and tucked it into the loom.

What else... oh yeah, you're going to have to grind the hole in the firewall for the new bulk-head to fit. It took me forever to realize that the bulk-head on the new harness is 1/4" wider than the original 85.

The 85 uses a unique style MAF, but it will work accurately with the new ECM.

I think that was it. It was a pretty simple swap overall.

 

Jim, you have no idea how good you just made my day. Now if i could just get an explanation of how to burn proms without any synonyms, acronyms, or abbreviations, i think my car would be fuel injected.

 

Check the PROM board on the IROC Homepage. Our PROM board is more beginner-oriented than the one here. Once you learn the basics over there, you can graduate to this site's more advanced PROM board. Also, make sure you read Traxion's tech article on this site. It's a little overwhelming the first couple times you read it, but as you learn a little bit by reading the boards, the information becomes more and more clear.

 

I just noticed that you're adding TPI to a car that is currently not injected. That changes things a little.

In addition to the other crap, you're going to need a new distributer. Your stock one has a vacuum-advance. The TPI cars control the advance through the computer. Those distributers are pretty easy to find used on Ebay for $50. Any MPFI distributer without the vacuum advance will work, including ones from the newer trucks. Since you're going to need to modify wiring anyway, you can use either the large cap or small cap distributer. I chose the small cap because down the road I plan to swap to a Super Ram or Stealth ram, and both of those need the small distributer because of clearance issues.

 

i'm gonna have to start just pm'ing you about everything. I know about the distributor issue, and i have to go small cap because of clearance issues i'm going to have with the other complicating issue, i'm swapping to an lt1 manifold. thanks for posting on the other topic i started, the ecm doesn't sound like it's going to be too big a deal, i ordered what i think i need from craig moates and i've got my eye on a friend's pp2. Your helping a ton, i appreciate it greatly. I think the only doubt i've got now is where i route hoses on the lt1...but i've got some people i'm talkign to about that as well. Thanks again.