Hi everyone, I have a 1989 Camaro that I had a Stock 305ci
TBI, and I switched it out with a build 350ci.. The 350 was said
to be bored 60 over, and had a high proformace Crank and Cam
installed.. Anyway.. I read that if you plan to upgrade from a stock
305 to a Built 350 then I may have to reprogram my PROM.. I was
wondering also about this paragraph I read..

"If, however, you are going to want to rip pavement, and you don't care about sad trees, crying hippys, or wilting flowers (none of which will really happen ...), then yank the PROM out and deprogram your ECM.

You'll find a rebel monster inside just waiting to be unchained."

He doesnt say to put the PROM back in. Do you?
PLEASE HELP ON PROGRAMING MY PROM

Please someone reply ASAP..
Thanks,
Doc

I was just reading a artical on reprograming your (ECM) Prome
chip at:
http://www.goingfaster.com/spo/tbi.html

 

You'll need to know what's in the motor. It may be incompatible with your current TBI.
Start here
https://www.thirdgen.org/newdesign/tech/promintro.shtml
Then once you know a little, This is a little of what might be involved with your set up https://www.thirdgen.org/techbb2/sho...hreadid=201468

 

When he wrote "deprogram" he actually meant "reprogram". You don't "pull the PROM out" to improve the computer operation.

That web article was written by someone who hadn't even read ECM fault codes, let alone programmed a PROM.

Your engine sounds like it's way to far modified to run acceptably on a stock chip. Read the stuff Scott directed you to, and ask some more questions.

John

 

That's not the most accurate material on EFI to be found. The Net's getting cluttered with alot of statments that are spoken in a universal sense, that aren't universally true.

 

that is my situation. tried to run a modified TBI on stock puter and stock eprom. did not work worth a darn. replaced the puter with a 7747 and noticed improvement in idle quality day one. with winaldl and a tuning program was able to make my car run so much better with every tuning session. still working at it. dont see why TBI will not work on a modified motor with a better ECU and corrected eprom...

 

I went mid 13s with a 747 in a 355 F Bod.
Mild cam, road racing type springs shocks, quiet exhuast, about stock converter. All with perfect manners.

While it would take alot of intial work the 749 would drive a 2 Brl TBI. It's a P4 ecm.

 

Thanks guys.. My ECM in my car is the Correct one for the TBI but
not for the engine. I just put the TBI on the new one I got.. The
car runs good, just seems like it there is something the
engine wants..
Sort of like pop-eye and a can of spinach..

The chip in the car was for a stock 305 thats 1989
and the new engine is a built 350 from 1986


respond ASAP

Thanks,
Michael

 

my ECU is from a V6 astro. my engine is a stock TBI crossfire 350 cid that has been modified just about every way. what you need is a new eprom programmed through data logging and changing the constants to reflect your motor size and mods with appropriate tuning in VE tables, ETC. I assume your ECU/eprom has been hacked. mine is a 1227747 which replaced the stock ECU which was not hacked. i dont see how you car would run very well with current stock tuning if i read this correctly.