IDTag

I'm searching, reading and trying to get up to speed on this but there's a lot of information to cover and I've got two used injection systems available right now.

I bought a 1985 that was an incomplete project. The PO had the engine built as a 383, 9.7:1, ported Edelbrock Performer heads, custom ground Comp Cam, auto trans but no fuel system. I picked up a Dana 44 with 3.07 gears so that'll replace the 2.56 Dana 36 that's in it now.

I'm going to be using the car for autocross and hillclimb, not much street time.

I have two options for my fuel system, a First Injection TPI setup or an Edelbrock Pro-Flo setup. Both are complete with ECU and wiring, both are usable as a standalone setups.

Here's what I think I figured out, please correct me if I'm wrong.

I believe either way I'm going to lose the digital dash.

The First setup looks like it produces more torque, the Pro-Flo more HP.

The First Injection setup is using a 91 Z28 ECU so I guess you'd have to burn a chip for it if you need to make changes.

I do want to keep the AC on the car. I think there are some parts of that system that are controlled by the ECU?

I had a 94 Caprice wagon with the LT1 and have TunerCat I used for programming. Not sure if I could use that with the Z28 ECU or not.

If there are other things I'll need to change if I remove the stock TPI and ECU, please fill me in.

Like I said, I'm doing my best with search but am paranoid I'll miss something and end up with lots more work. I'm leaning toward the First TPI.

blackozvet

do you have an 870 computer (used on 85 and early iron head 86) ?
one option is to use your sensors and throttle body in the system thereby being able to utilize your original wiring and computer, then get a chip burnt to suit your mods,

im sure the First system uses its own single blade throttle body so therefore would use its own TPS, IAC and a mass air pressure system, therefore you would have to start changing things that arent compatible with the original 85 wiring loom, you could tackle it if your confident in changing out that kind of stuff but it will present hurdles,

There are people here who have swapped over computers in 85's, but i gather by their subsequent threads with the problems and issues involved re-wiring and re-pinning that its no walk in the park, probably easier to get an 85 chip burnt and be done with it.

tunedport85inject

Why not a miniram intake fitted with a 165 ECM from a 86-89and wiring harnes from a donor?obviously a custom chip burned for specific aplication.You can find ECM and wiring on Ebay and just buy the intake rails, and injectors.probably a cheap way to go...

dragracer111

I did about the same thing you are trying to do. 383, fast efi, dana 44 on my 90 vette. If you leave the stock ecu hooked hooked up and use the stock water temp, oil pressure and transmission wiring your dash will still work. If you have air and cruse you will have to make sure the computer gets a tach signal to keep those working. (thanks again vette oz) You will also have to replace the distributor.

coupeguy2001

why not buy the plugs for the 86-89 corvette 165 computer, repin those connectors with your existing wires to match the 86-89 computer, and add the wires for mass air and burnoff relays, and pretend it is an 86?
you probably have all the wiring for the sensors in the car already.
you can use the first manifold, and factory wiring.

tunedport85inject

This is a well known thread on third gen about repinning a 870 wiring harnes to swap to 165 86-89 ecm,a little tricky becouse of repining and adding two power and burn off relais,but doable...my advice was to source a complete 86-89 wiring to jump over the repinning

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

MrWillys

The speed density system will get the job done, and because you're already familiar with Tunercat tuning should be a breeze. Now just choose between torque and HP and you're off to the track.

tunedport85inject

In this case you have to find a 727-730 ecm from a 90-91 and wiring harnes and fit a cheap MAP sensor to your intake plenum and you'r in business

coupeguy2001

He said he has both the wiring and the ECM from the 91 Camaro. the easiest way is to swap out the harnesses from the car to the Camaro harness, and mount the ECM in the original location if the wires are long enough.
I would guess that the Camaro ECM ran the A/C like the corvette, but the digital dash might just work if he repinned the two connectors.
The hiccup here might be that the two ECM's are physically the same size, but the Camaro's connectors are on the side of the ECM but the corvette's are on the end.
That little bit extra wire may make the harness a little short, making him modify the bracketry in the corvette to adapt the ECM from the Camaro.