Will using an ecm and matching engine harness from a non VATS car be an issue when installed into a car that has vats from the factory? The car will start but not stay running. No security light. I am asking for a friend that did this swap and cant figure out the issue. Any help is appreciated.

 

Since the car that didn’t have vats is being swapping in to a vats car the prom in the ecm will not expect a 30hz signal. You can get rid of the enable circuit for the starter if you want by bypassing the relay. Or if passkey still works leave it for a theft device.

 

Start with the basics, fuel pressure at prime, checking for codes and setting base timing .

 

Ok. So should he remove the wire from the connector going to the ecm that sends that signal?

 

I’m not following, if the chip calibration doesn’t have vats enabled in it having a hz signal to the ecm doesn’t effect anything if that’s the question. If it’s piping check for injector pulse. If no pulse and bleeding off fuel pressure the injectors are leaking or bad fpr. Start with the basics to diagnose.

 

I want to run a 1989 Prom that has VATS enabled in my 88 that didn't come with VATS will the car run using the 89 chip?

 

Disable the vats in the tune, or use a timer shop hz modulator to give The ecm 30hz signal.
of it’s a vats enabled late 88-89 1227165 tune no you will not have injector pulse unless you do one or the other options.

https://www.amazon.com/Timers-Shop-PASSkey-Bypass-Module-Painless/dp/B074YZ6XPM/ref=mp_s_a_1_3?crid=3PRFCCNOWRJYW&dib=eyJ2IjoiMSJ9.vxwzoRWDiTnilxpPVGo98AMAOIHOh3lpURmMMCiEZBS_lS0PEO7vebBwSGjRey6XXgJ2PCmcPo49lDcSe2sWoGnCmbX3Cc0pNEhZlwoRtB6vssjucWPStNNqbaBCu90AYmK8SVeTP6ZuNqYHGUnSkkuplAW61ickhunzEeoJFFkTbKYSiX6dOejF2UELyAT-_RN8GyuKUZhPc_dG8l7jJQ.0MKZXOJMUM7vPeFHwtPWUGM2VRI7xN1Dl14q22Vk-E8&dib_tag=se&keywords=vats&qid=1761351167&sprefix=vats%2Caps%2C153&sr=8-3