beaner104

I need some help with wiring issue. I have a 1992 convertible that the 3.1L v6 was removed and I dropped in a 1987 5.7L TPI motor and trans. I have all of the wiring from the engine compartment and ECM / computer from the 1987. The interior wiring / ECM is the 1992 V6.

If I use the 87 ECM I don't think the interior, dash, pass key will work. The 92 is not going to run the 87 5.7L.

Does anyone have any good suggestions on this.

Thanks

Maverick H1L

iTrader: (8)

Yes, the VATS will still work. All of the VATS wiring is in the dash harness right up to the starter solenoid wire. Your speedo, on the other hand, will not. You will need to find an early VSS and buffer box (or get the parts from a TBI car) to work the speedo. There will also be some rewiring under the dash to get power to the fuel injectors, which have a separate connector for the power wires.

There may be some repinning to do in the big connector by the brake booster for the engine wiring, but most of it already hooks up.

beaner104

So are you saying to use the 87 ecm/ computer, and you think it will run the interior for the 92 excpet for a few issues?

Thanks

Maverick H1L

iTrader: (8)

Need to know what trans before I can tell you what's what...

I did the same swap but in reverse... 91 engine harness to 87 body. I have both the 92 and 87 FSMs, so I can look up the differences. I can tell you, right off, that the wiper motor wiring in the 87 harness will not work with your 92 wiper motor as they redesigned the motor in 88, and the wiper wiring can be removed from the engine harness.

The ONLY difference with the interior wiring you need to be concerned with is the VSS and speedo wiring. The red wires in the big connector by the brake booster still feed the ignition switch and the fuse panel, and from there, the interior harness.

beaner104

It is the stock automatic transmission that came from the 87. 700r4? maybe. Thanks for all the help so far.

Maverick H1L

iTrader: (8)

I actually have a text file (with connector graphics) written up for the conversion from 90-92 to 87. If you PM me your email address, I can make the V8 changes to it (currently for V6) and send it out to you. You would, of course, follow it backwards.

project89

iTrader: (1)

umm the v6 ecm is a 7730 why not just add the 2 extra injector wires and get a v8 prom for it??

u would have to reuse the v6's map sensor or buy a new one if u threw it out

that would be the simpest route

vetteoz

iTrader: (13)

Just remote mount the MAP sensor like on the TBI engines and run a vac hose to the port on the TPI plenum
And you get to reuse all your existing speedo setup