Would a non vats stock chip work in my vats equipted 89 Formula w/350? Everything else is correct on the chip ex. it's from an 88.
Will it work? I'm not concerned about defeating the vats setup at this point.
Thanks!

I'm not sure. Call GM & see if the ECMs are the same between '88 & '89 for the same motor - they probably are not the same, since the '89 probably has a VATS signal input. Then again,......you could just try it out - the ECM may give you an instant fault code like invalid PROM ID.

Tim

Will do! Thank you Tim!

The ECM is the same, 7165 MAF, but I dont think the chip would provide the correct signals to the computer, like VATS. Try it and see. It wont hurt if its wrong, the car either wont start, or wont run right.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

Just tried to start the car--cranked fine also was getting fuel and spark--but wouldn't start! Wasn't even getting a check engine light(good bulb). Not sure which chip is in there, hopefully I have the 86 chip in there and that's the problem!(that would be TOO easy!)
I'll keep you updated!
Thanks!

Guys,

The 88 code is $32B and the 89 code is $6E. They have completely different microcode in the GM program on the back half of the PROM. One small reason among the many other reasons is due to the fact that the '88 used a cold start injectors and the 89 did not.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

I want to clarify the above post somewhat.

Moving from '86-'88 code to '89 code is a good thing. You get the benefit of getting rid of the cold start injector and the benefit of having the latest 165 code from GM. In fact, this is what TPIS does if you install a MiniRam on an '86-'88 TPI engine. They upgrade you to '89 code because the MiniRam has no provisions for the cold start injector.

However, I am not sure about using the reverse procedure ... installing '86-'88 code in an '89. IMHO - this is a downgrade. But, will it work? I am thinking that it would not work because the '86-'88 code would be attempting to pulse the cold start injector on startup and there is no cold start injector. Thus, the engine will probably not get enough fuel on startup and thus, might not start.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Hmm, I guess that sounds possible. I have to get my hands on an 89 chip. My 89 computer had a Superchip in it, but I think the mechanic screwed it up some how! Before I tore into the harness I used the 86 chip in it and it started. Any way to test the Superchip? Could anyone on the board check it? I'm kind of at a stand still right now!
Would the 86 chip cause the check engine light not to work? CONFUSING!