Idle is reving 200rpm more after chip change. The new chip is leaner at the lower RPM's.

When changing a chip, does the timing on the dizzy change with the respective new data on the chip?

Not sure if I'm making sense.

Ctown

 

"Idle is reving 200rpm more after chip change."

I don't understand what you mean.

"When changing a chip, does the timing on the dizzy change with the respective new data on the chip? "

The only way the timing changes is if you move the distributor or if the values in the EPROM have been changed by someone.

THe ECM doesn't "learn" timing.

 

Gracias for the help.

Ctown

 

Base timing will not change, but the chip may change the timing curve.

 

Holy smoly!

What a difference!

The other day after switching the chip, I read a post about advance timing when running leaner. Just to run a little experiment, last night I turned the dizzy for less advancement and it ran like turd!

This afternoon I put it back to where it was and added a little more timing and the outcome is what I have been searching for years...from this 3600# truck for quite some time now...

WinALDL data looks a lot better that the other chip. Might have a bad MAP sensor.

Ctown

 

so what your saying is if your running lean then try to advance timing to some what cure it? cause i pulled my year old plugs and they were white as hell....so i retarded the timing to 4advanced from 6advanced do you think i should go higher than 6adv? i do have a vafpr that im waiting to pick up from a local dealer to help with the problem