Bonehed

Well I have received a free 85 IROC from a girl who didnt want her x to have it. Life is good. Originally had the LB9 305 TPI motor in it. Not anymore, engine code tells me the block is from 83 firebird, still a 305. 1. There were 3 alarms installed and have been ripped out, making my wiring harness a nightmare. 2. The ECM was blowing once a month or so. 3. Transmission is stuck in 2nd gear, i believe it needs a rebuild and is not related to the ECM, no? 4. Cooling fans werent working right. This is all hearsay. One thing for sure. It doesnt run..hehe but hey, the price was right. I am also led to believe it has a cam, and aftermarket heads in it. I was considering just yanking the TPI for now and carburating it. Ideas, suggestions, let the games begin.

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Vader

Bone,

One man's medicine is another man's sugar. Looks like you get the sweet end of the deal this time...

I'd troubleshoot the TPI system first to see if it is viable. If it gets too intense, you could always opt for a carb and intake, and send the TPI to another buyer. The TPI will probably be better for torque in the long run, and unless you spend a lot of time in the ¼ mile, the carb can be less appealing.

The casting numbers on the engine can be misleading and confusing, so it's a good idea to check the I.D. number against the VIN:







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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
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Bonehed

Well after some research and some replies to a better worded question, I think I am going to search for a wiring harness or do one myself and try to make the TPI work.

mtccl

Summit sales a TPI wiring harness.

Bonehed

Summit only has them for 86 and up TPI. I have been reading quite a bit about this now.

Will an 86 harness and ECM work with this 85 TPI unit? If not, what can I change to make it work? Near as I can tell there was vast improvement in the 86 module, and not too much else changed.

AaronIROCZ

iTrader: (5)

You should be able to get a 86 harness to work on your car. But you might have to get a 86 computer though since 85 has a burn off module instead of a relay. Correct me if i am wrong. All is quite simple if it will all work. I had to rewire my whole engine compartment on my 87 Trans Am GTA that had a engine fire. It was time consuming but I would do it again. The hardest part was routeing all the wires to make it a clean look. Good luck

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89 Iroc 350 TPI,
Forged pistions
Comp roller Cam .510 lift 230dur
Flowmaster exhaust
Dart Iron Eagle heads 200cc runners 64cc chambers
LT1 intake soon...if I can find one!!!
stock TPI for now 24# inj
87 Trans Am GTA 350 TPI
had engine fire
SHE NOW RUNS!!!!
Flowmaster exhaust
LT1 Injectors
LT1 intake also if I can find one!!

AaronIROCZ

iTrader: (5)

also summit has the painless wiring kit for the tpi. It is a standalone kit to get the engine to run it does not have other stuff like cooling fan, ac wiring. YOu would be better off finding a factory one, alot less work.

Gruvin84SS

yes you can use the 86 harness on the 85 with the change of the burn off setup. i would actually recommend this. the 85 TPI ECM is junk. i have 85 TPI intake stuff with 90 SD wire harness and ECM. the 85 TPI fit my older bolt pattern engine and the Painless speed density harness fit like a dream into my monte carlo SS. a factory harness will be an easier install on your car since it is designed to be there and you use all of the entire harnesses functions. mine the painless harness made it easy so i did not have to seperate the other stuff from the TPI controls.

Bonehed

I think Im getting a grasp on this schtuff. Thanx for all the replies. Im going for the 86 wiring, ECM, and burnoff thingy. Found all the wiring diagrams and a great description of the TPI history, and what the different components do. Think I'm well on my way.
Just need to fine out more about PROM, and find out what cam and heads are on my car without pulling the engine.......