I was checking my ignition timing today and set it at stock 6* btdc and noticed that when i reved it up that the timing jumped to 10* after so high of an rpm. I thought when you unhooked the EST wire that there wasnt supposed to be any timing advance. Its pretty consistent too. Does the ignition module advance it any or does my car need a timing chain or the distributor gear shimmed or something else? It only has 67k miles on it but i can hear a faint noise behind the waterpump. I'm going to check and see how much the rotor rotates compared to the crank pulley tomorrow. Thanks for any help i can get.
Scott

 

I read on here not too long ago that someone said the ICM begins advancing spark timing on its own >600 RPM.

 

I believe the jump is somewhere around 1200 or 1500 rpm.

I might be wrong on this but im almost 100% sure its higher than 600rpm

Has a small amount of advance built into it as a failsafe if the computer cannot control timing it has a small amount of advance there at x rpm to give it more timing at higher rpm.

later
Jeremy

 

Thanks you guys. I was starting to think i had something seriouly wrong. It is very consistent when it jumps. It stays at 6* then 10* when it jumps.