A 1989 PROM from a TPI will work in a 1988 TPI? Both identical size engines and transmissions. I know a 1988 PROM will NOT work in a 1989 ECM due to VATS but what about the other way around?

Maybe I just answered my own question?

Any gurus out there?

Chris

 

If the '89 vehicle has VATS, the PROM will be expecting the input to the ECM.

 

The computers are the same part#, however...

Not necessarily the same trans in one critical way, in '89 the switch began from optical VSS to magnetic VSS. If your '89 PROM is configured for magnetic VSS you'll have issues running it with input from an optical VSS.

The '89 software will be looking for VATS input, though.


Now sure how you know that, because it's wrong. Pop an '88 PROM in an '89 ECM (which again is the same exact part#) and the VATS input provided from the car's system is effectively ignored by the '88 software.

However, the '88 software will be expecting a 9th injector during cold starts which isn't there on '89 TPI setups. Will be difficult to start.


Sorry, but just us amateurs. Gurus charge money.

 

I've got an 88 PROM if you want to swap. I'm actually looking for one from an 89.

The PROM I have is from an 88 350 Trans Am GTA auto trans car. I'm looking for an 89 305 Auto chip. Actually the trans doesn't matter for what I need because I'm pulling the main chip out anyway. I just want the correct memcal because of the other 2 chips for correct closed loop values.

Email me if you are interested. 350t5@***.net

 

Sent you an email

 

So, to answer my question, no. At least not effectively. What about a 350 chip in a 305?

Thanks for the response. That is why I love this place, all the "amateurs"

Chris