timing not advancing with est unplugged

[jeff89fbird]

Base timing is at 9-10, but retards about half a degree when I rev it. The ignition control module isn't that old, but I'm going to try replacing it anyway with a better brand (can't remember what's in it now)

The timing is around 20 with the est connected and advances when I rev it.

anything else I should look for that would cause this? The car seems a bit weak at higher rpms, and if I'm not getting enough edvance then thats probably the reason.

Car is an 89 with a 3.4, MSD 6a, blaster coil, and msd cap and rotor. I'm going to try bypassing the msd box too just in case.

[robertisaar]

ummmm...... the timing shouldn't advance if its disconnected, if i remember the way GM ECMs operate, it should actually retard it...

by disconnecting it, you're essentially throwing it into limp-home mode.

[geoffinbc]

Agreed. There is nothing wrong. Timing wont move without the ESC.

[carbon]

Yeah... that was basically the quivalent of limp mode for the ignition, if the ecm ignition control failed.