C4 "computer" problems...corrupt data?

Hi All,

My '94 has not been running normally. When I give it full throttle there is
a brief pause before full throttle is applied. There is maybe a half second
before the power comes on normally. No missing, hesitation, stumble,
etc...it just takes longer for full power than it should. The only other
symptom is that when it is cold and I have the A/C on, it will backfire
through the intake.

The guys at the local Good Year store where I've had it serviced for years,
say that it showed an "EPROM" code, meaning that the data in the EPROM in
the computer was corrupt.

I know that if I take it to GM for reprogramming it'll cost ten times what
it's worth.

My thought is to buy a Hypertech Power Programmer and reprogram it that way.

Your thoughts, please.

Steve... how many miles on your car? Most problems were with the OptiSpark
inition system. A computer code doesn't mean there's a problem with the
computer, it might, but that's unlikely. I'd first verify the ignition is
working correctly, if so, then clean up all the connections to the grounds
and computer.

Gerd

"Steve Duncan" > wrote in message
...
> Hi All,
>
> My '94 has not been running normally. When I give it full throttle there
> is a brief pause before full throttle is applied. There is maybe a half
> second before the power comes on normally. No missing, hesitation,
> stumble, etc...it just takes longer for full power than it should. The
> only other symptom is that when it is cold and I have the A/C on, it will
> backfire through the intake.
>
> The guys at the local Good Year store where I've had it serviced for
> years, say that it showed an "EPROM" code, meaning that the data in the
> EPROM in the computer was corrupt.
>
> I know that if I take it to GM for reprogramming it'll cost ten times what
> it's worth.
>
> My thought is to buy a Hypertech Power Programmer and reprogram it that
> way.
>
> Your thoughts, please.
>

Steve... how many miles on your car? Most problems were with the OptiSpark
inition system. A computer code doesn't mean there's a problem with the
computer, it might, but that's unlikely. I'd first verify the ignition is
working correctly, if so, then clean up all the connections to the grounds
and computer.

Gerd

"Steve Duncan" > wrote in message
...
> Hi All,
>
> My '94 has not been running normally. When I give it full throttle there
> is a brief pause before full throttle is applied. There is maybe a half
> second before the power comes on normally. No missing, hesitation,
> stumble, etc...it just takes longer for full power than it should. The
> only other symptom is that when it is cold and I have the A/C on, it will
> backfire through the intake.
>
> The guys at the local Good Year store where I've had it serviced for
> years, say that it showed an "EPROM" code, meaning that the data in the
> EPROM in the computer was corrupt.
>
> I know that if I take it to GM for reprogramming it'll cost ten times what
> it's worth.
>
> My thought is to buy a Hypertech Power Programmer and reprogram it that
> way.
>
> Your thoughts, please.
>

The opti-spark does cause alot of problems.

Also, I think the '94 PCM may still use a computer chip (PROM) instead of
software.

The PCM is also under the hood. Older GM PCMs under the hood do not live
very well due to heat cycling. A good example would be GM W cars with the
PCM under the hood. So, could be a bad PCM.

The Hypertech would not be able to program a software based PCM. The
Hypertech tool only changes about 1% of the original PCM software.
IF..thats the type PCM you have.

Logan Diagnostic
http://www.airbagcrash.com
http://www.ledfix.com

The opti-spark does cause alot of problems.

Also, I think the '94 PCM may still use a computer chip (PROM) instead of
software.

The PCM is also under the hood. Older GM PCMs under the hood do not live
very well due to heat cycling. A good example would be GM W cars with the
PCM under the hood. So, could be a bad PCM.

The Hypertech would not be able to program a software based PCM. The
Hypertech tool only changes about 1% of the original PCM software.
IF..thats the type PCM you have.

Logan Diagnostic
http://www.airbagcrash.com
http://www.ledfix.com