rickzcamaro

iTrader: (1)

I'm putting in a 350 tpi motor into my 91, BUT I have a tpi harness and ecu from a 92. My understanding is the 90-92 have esc is programmed into the PROM and not external like the previous years.*
My question is can a 305 prom be programmed to work with my motor, can I use aftermarket PROM, or do I have to have a 350 PROM from a 90-92?

aliceempire

iTrader: (14)

You can't reprogram the chip that has already been burned. If the engine you're putting in is stock specs then its not hard at all to find a 350 prom and put it in. Tables will be different between the two. Otherwise if it's a modified engine my suggestion is go ebl-p4 and tune yourself on the fly.

rickzcamaro

iTrader: (1)

This is the first time me dealing with any gm ecu. I'm use to Ford and everything is just plug in and play.

Only mods I'm doing to the car is lt1 cam (I already have one) and exhaust

aliceempire

iTrader: (14)

An LT1 cam is tame enough that a retune shouldn't be required but a retune would make full use of tge mod. 90-92 speed density tpi refers to engine vacuum to base fuel trims to, so any change in vacuum will affect how well it runs. A 350 prom for your drivetrain should work just fine.

rickzcamaro

iTrader: (1)

There is no way I can use my 305 prom?

aliceempire

iTrader: (14)

It'll run with the 305 prom. Sure. It won't run as well as it should. Best guess without looking at the spark and fuel tables of both it'll run lean. Possibly dangerously lean. 45ci to make up for. Honestly on the classifed boards proms pop up regularly. There is the member TunedPerformance here and he'll burn you one and customize it too if you like.