Hi,

I'm looking at buying the following setup to put into my 87 Z28 (LG4). It is coming out of a 89 GTA
- 305 - complete minus PS Pump
- Dash Harness
- Engine Harness
- ECU
- Fuel tank/pump/lines

From my research, I can tell I will need to purchase a throttle cable and most likely a VATS bypass module. Is there anything else I would need?

When I look at the wiring diagrams I notice there is a wire running to the transmission. Will my transmission (700r4) function properly with the TPI setup or does the chip need to be reburned (as the car the engine is coming out of is a 5 speed)?

How will my current gauge cluster work with the new setup? VSS doesn't seem to be an issue if my research is correct since 87 and 89 both expect the same PPM?


Is there anything else I need to have the swap up and running? Are there any questions I need to ask the seller? He tells me it's everything I need, but not having done it before I thought I'd double check.

 

The T5 harness won't have the TH700R-4 leg. You probably need to start looking for an '89 TPI auto harness ('86-'88 had the cold start injector, which yours doesn't - not sure what that does to the pin-out). The ECM should be okay, but the PROM won't have the TCC lock-up.

Sounds like the right time for a conversion to manual transmission. . .

You should be able to do the VATS bypass without wasting money on a module. Check out the VATS tech article.

 

What would happen if I didn't get another harness from an automatic car? And would I need the entire engine harness, or is there only a small piece I need?

Would not having the TCC lockup cause any problems?

 

No TCC lock-up isn't good for the tranny - burns out the 3-4 clutch pack.

You might be able to pin the tranny harness into yours, but you'd need to start at the ECM and go through the kick-panel bulkhead connector.

 

Do you think that's what this kit is for?

http://www.larryselectricsite.com/700r4.html



Either way though, even if I could get the transmission working I would still have the issue of the TCC not locking up and the only solutions would be:
a) Get the ECM/PROM updated
b) Put in a manual
c) Put in a harness from an automatic (and it would have to be 89, for the lack of cold start. Or I'll end up having to get the ECM/PROM reprogrammed for the cold start anyways)

So, in addition to what I can purchase from this guy I need to put aside $100 (What I assume the programming would start at) -$800 (What I assume a 5speed swap would cost) to solve my transmission problem?

 

That's what the Larry's kit (and others like it) do, lock up the TCC. That particular kit locks the TCC when the tranny shifts to OD if there is sufficient vacuum and the brake is released. Or, to put it a different way, the TCC will be locked in OD unless vacuum drops to a certain level (engine under load) or the brake pedal is depressed. No PROM tuning required.

Your car should have the pieces to do the job if you're willing to tear apart your existing harness and do the PROM thing.

Oh, the "PROM thing" would be to find an '86-'88 305 TPI auto PROM.

 

Well, if all it takes is the $75 kit to fix this whole thing it's not that bad afterall.

I just talked to the guy, he says the 305 came out of a GTA convertible that was an auto and his harness and computer are both for an auto. I assumed 5 speed since he said it was a 305 GTA, and the tech data here doesn't show the 305 GTA ever coming in an auto.


So, if the harness is actually from an auto I should only have to worry about the vats bypass, and that's minor if I follow the tech article on the site it seems.

Any other issues you can see or questions I need to ask?