Hi everyone new here and in the world of camaro’s.
I bought a 87 305tpi iroc with a engine that have been full of water its beyond saving,
i have the possibilty to buy a 91 350 tpi with ecu and engineharness.
I have read quite a few posts on herr but would i be running into problems with my gauges if i use this ecu harness?
Would it be better to stick with my old intake/throttlebody/Maf and old harness ecu and change knocksensor injectors chip in ecu?

 

It might be easier to use the 1227165 original harness and get a different tune or calibration chip. The 91 1227730 has vats and iirc the 87 has a speedometer cable and the 91 used a Vss on the transmission.

 

Use the 87 100k knock sensor if staying with that ecm. You can swap passenger runner and fuel rail and 87 plenum to the 350. Other wise you need a 89-92 throttle cable.

 

Ok great info there!
So this being a car that has been sitting for 15+ years it needs alot of other work done will it be possible to run it if i change the injectors but not the chip until i get one made/bought in and out of the garage and easier testdrive?
If i choose yo use the ecu that comes with the engine do i also need ignitionswitch and instrumentcluster from that car or can i use my 87 cluster and speedo wire.

 

You might do a comparison on c207 by the ecm. The ecm needs a 4kppm
vss signal to the newer 1227730 ecm. If you have a Vss buffer box net to the ecm you can use that to give the ecm the signal. You might have c100 difference in the fuel pump feed through the body. Just a few things to consider. You can use the 305 chip and 22#hr injectors but it will probably run rich .

 

And don’t forget you need to bypass the vats in order to use the 1227730 it depends on how complete the under dash harness is in the one you have from the donor car.
no need to swap the ignition and the gauges are not hooked to the computer.

 

What did the 1991 5.7L L98 engine, wiring harness, and ECM come out of?

How complete is the L98 engine assembly? Pictures if you have them.

Do you have access to the car it came out of to get additional parts for the swap if needed?

 

The engine is out of another camaro but by how this sounds ill stay with the old ecu and harness and get another chip and knocksensor what about the cold start injector do i need to move that to the new engine or can i run without it?
Also i did get a ads superchip strip chip with the car will this make it run even richer?

 

The csi can be blocked, use this https://ebay.us/m/krF8ro
and easier starting with a custom 89 based tune. Im
not sure how much more the superchip will make it run richer but good enough to see how it runs. I’d use the 87 drivers side runner and plenum so the tb has the correct iac passage is there.

 

The old rusted engine

Also the old engine

The replacement motor problably going to open it up and check the condition atleast its not had water up to the pistons..

 

Pull the spark plugs, use a scope and look at cylinders. Can also prime the oil pump and lube down the cylinders and do a compression test.