98z28bitcha

iTrader: (22)

What would cause the PCM load a tune with hp tuners
Run fine and then when u shut off the car(after the tune has been load and saved)then start back up it acts like tune is not there. What would cause it a bad PCM?

Thanks in advance Rob

98z28bitcha

iTrader: (22)

Ps I have a 98 with a 02 PCM in it.

slow

iTrader: (7)

bad tune, or the keep alive memory of the pcm is not connected to constant power (Blue Pin #19/20 reversal?)

Those would be my guesses. I never had that issue with my 98 swapped 2002.

Ryan

98z28bitcha

iTrader: (22)

I'll have to check the pin this weekend but I know the tune is not bad cause it runs strong until u shut the car off.

98z28bitcha

iTrader: (22)

Check the pins nothing wrong there but i got another a pcm so ill see if that does it.

TunerGuy

Are you sure the battery power is staying on at least 30 seconds after the ignion power shuts off?

edcmat-l1

iTrader: (10)

Just because it runs strong doesn't mean the tune is right. You're comparing how it runs to how it starts? There's so much more to tuning the startup and open loop conditions that it can run fine once running, but be very difficult to start, or run like **** right after startup, and then steadily get better the longer it runs.

Without a data log and tune, all anyone can do is guess.

highgear

I was told by EFIlive that 97-98 PCMs were wired different and could not be swapped with later models.

TunerGuy

They're not plug and play, you need to repin the harness,there are several guys on here that have done this mutlible times, bigboykillroy comes to mind. If you still want you fuel gauge to work properly, you need to swap the fuel segment on the 2002 OS or if its not a 2002 OS you're running you need to convert the fuel gauge output to PWM instead of class 2 date buss
By the way I see in your sig you have an A4, if you do the upgrade the biggest thing you'll notice is the car will stop hitting the rev limiter, byfore shifting. This is caused by the much slower proccessor speed in the 98 PCM's