I was planning on putting a full setup from a 91 305 TPI into my car, but then I found a guy who will sell me the entire TPI setup, the harness, and the computer from his 89 IROC with a t5. That will make the install on my 89 RS (also a 5 speed) so much simpler.

here's the question... Other than the entire TPI setup, air intake including the MAF, harness, and the ECM, what else do I need to make sure I grab from the 89? Any differences in the intake manifold? Any sensors on the block or exhaust manifolds that are different? What about differences in the Distributor?

 

Mark I put a '91 L98 in my '89. The 91 has a completely different ECM than the one in the 89. There are 3 connectors that go into the ECM on the 91 setup. I take it your 89 is a TBI 305? I hope you know that wiring a car from a TBI to a TPI is not an easy task for someone unless they are above average mechanic. The engine you swap make sure that all of the guys wiring is complete and hook everything up before you install it in your car to make sure it has all of the required connectors, 8 Injector connectors, TPS, AIR, EGR, EGR Solenoid, HEI Distributor, Oil sensor, Neutral safety switch and a whole bunch of others. Don't for get all that wiring has to be spliced into your existing harness for fuel pump, VATS, Charcoal canister fan relays etc. etc.

There is a really good book out there that explains in detail what you need to do the swop and supplies all the part numbers and very helpful info. I forget the exact name of it but it's titled How to swop a TPI into you vehicle.

The swop is well worth the trouble once you get all the bugs worked out. Oh, you will need to replace your in tank fuel pump with one for a TPI, the TBI pump will not work!

Best of luck!

 

ok, here's more details

right now i have a 89 v6. i have a friend that has a 91 z28, and he's putting a ls3 in it. we had discussed taking everything that he would remove for the swap and putting it all in my car. literally everything i would need, he would have. the main problems would be my lack of an electronic speedometer, the differences in the harness between 89 and 91, and the fact that his ECM is for an automatic

and then 2 days ago a mutual friend tells me he has an 89 iroc, and the ecm, harness, and tpi system are available. After thinking about it, even though the MAF isn't quite a good a system as the 91 had, the ease of the swap will make it a lot easier. we are taking the 89 TPI, the 89 wiring harness, and the 89 ECM (t5) and putting it on his 91 engine. also using his exhaust and all the other little things we will need

the purpose of my question was i wanted to see what i needed to grab off of the 89 that we will need that his 91 will not have. For example, i found out today that the EGR is different for those two years

does that make sense?

 

The 89 tpi is much more simple to install on your car over the 91. I wouldn't call the 91 system better either. Both systems have there pluses and minuses.

Take the complete 89 engine compartment harness and everything will work. The 91 will require pins to be moved. Take the air intake (cause obviously you need the MAF) and intake manifold. (upper plenum is slightly different.) Accessories will be the same as the 91.

There isn't a lot different other than harness and everything else you're already taking.

 

The computers are identical year for year
Only the removable memcal ( chip ) fitted inside determines what combo it is setup for

 

OK, that original setup from the 89 T5 car fell through, but I found another setup identical, but it's from an automatic car. If I get the ECM, do I have to get a new Memcal burned to match the t5 setup in mine?

The cost of a new MAF is enough to make me sick to my stomach. the only one that can be considered affordable is the wells MAF. I hear pretty good things about those, I guess that's the way to go

 

Yes you can just replace the memcal with a manual trans one. Tuned Performance on the boards can set you up if need be. It will with work the automatic memcal but it won't be completely normal. All you'd need to change with the wiring is add your existing reverse light wiring to the new ones c100 connector. The lock up wiring can just hang.

 

An 89 iroc with a complete drive train just fell into my lap. . I'm going to go with it that way. . I don't love the maf system, but it's too good a deal to pass up.