1990 RS 305tbi. Im doing a complete tear down and have an 04 Vette LS6/T56 with the factory harness/PCM from the vette.

I know that when I send the Vette harness and PCM in for rework they will program vats and other emissions out of the PCM, so no biggie there.

My question is how do I completely eliminate the factory 1990 VATS system? Can I use an under dash/column harness from and earlier year car that doesnt use VATS? Or can I jump any wires together? Needless to say I wont have the factory TBI ECM worry about burning a new Chip, and the Vette PCM should power the fuel pump relay anyway...

As of now the car has the factory pellet in between the two wires with just a normal ignition lock cylinder/key. It works fine, but I do not want to have any issues with the Factory 1990 VATS in the future

I've read as many of the threads as I can find, but nothing really relating to what I'm trying to accomplish.

Thanks guys.

 

The only thing you may have a problem with would be the original starter relay. It would normally be activated by the ECM through your original harness. Seeing you are replacing the harness, everything from the vette will make the engine run but if you need to use your original dash harness, you may need to jump the starter relay or provide a signal from the vette PCM to the relay to energize it. The wires in your column for VATS go to the VATS module. That module then signals your ECM that everything is ok and it can energize the starter relay and fire the injectors for fuel. You are eliminating all that so no concern except as stated above about the relay. HTH!

 

Correct. You can either jump wires at the start relay or jump wires at the VATS. I jumped at the VATS. Link to my thread with a very clear explanation (post #303)....


https://www.thirdgen.org/forums/ltx-...ml#post5963351