ManWitThePlan

I have a 1991 RS that came from the factory with a 305 TBI and a 5 speed. I bought a wrecked 1990 IROC with a 5.7 liter TPI and a 700r4 transmission. I swapped the 5.7 liter TPI into the 1991 RS using the TPI harness out of the 1990, i used everything including the computer. my problems are that it keeps blowing the Acc fuse and the engine will not crank, it seems to me that the injectors are not firing because i can spray gas into the throttle body and it will run for a second or 2. I have searched and searched and searched and it looks to me as if no one has done the 90 into a 91 or 92 swap. I am a dummy when it comes to wiring but if you can lead me through it I would greatly appreciate it.
Thanks
Barry

86TATpi

Have you changed the fuel pump? And are you using the 5-speed or the 700?

ManWitThePlan

yeah i changed the entire gas tank from the IROC. and i am using the 5 speed behind the 5.7 in the RS.

david roush

iTrader: (1)

What is your SES light doing?......does it function properly?

ManWitThePlan

it wont read a code if thats what your asking

Dyno Don

iTrader: (7)

I've done the swap but the IROC harness doesn't just plug and play in the RS. Several things have to be switched around, that is most likely why you are blowing fuses.
In the 15 pin connector there are a few diffences, the IROC doesn't use the crank provision (ppl/wht wire) or the speed buffer(little yellow box) so the wires have to be moved. So do the speedo wires (reposition them in the 15 pin connector) they are brn & red. The yellow and ppl wires have to go to the computer thru the 15 pin (from the buffer). I have no way to show you but there is an article here on TGO that will help.

ManWitThePlan

don do you have a link to that article, i have been searching for about 2 weeks now and i am about ready to just sell this car.

david roush

iTrader: (1)

The reason i asked about the SES light was because i had the same exact problem. As long as i sprayed carb cleaner in the throttle body the car would stay running but as i soon as i stopped , it would shut off. My SES light would only blink once and then go out.For the life of me i can't remember what the hell i did to fix that problem, i'll give it some more thought...Eventaully my prom chip was no good though, which is why the SES light was'nt operating properly.

Dyno Don

iTrader: (7)

Here ya go:

https://www.thirdgen.org/newdesign/tech/tbitotpi.shtml

Dyno Don

iTrader: (7)

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