Hey guys... I was under the impression, when disconnecting the tan/black wire the distributor will go into 'no advance' and should show the 'stock' (set) timing, for example 6' BTDC...

If you rev the car with timing connector disconnected, it should still remain at 6' right? Even if reving to like 3,000 RPM, is that correct?

Reason I ask... is my car... will add about 8' degrees of timing, even disconnected... when you rev the motor.

Can someone chime in here?

And I'd love it if someone could try to re-create this... by checking there timing, with tan wire unplugged... and seeing if it still advances when revved up over 2,500 RPMs'.

Thanks!
Dave

 

With the tan/blk wire disconnected, the ICM goes into bypass mode. In bypass mode, spark and timing are controlled by the ICM itself, without input from the ECM. The ICM has a base timing map built into it so that the car can be driven incase the EST system fails. So yes, the 8 degrees advance, in bypass mode, is pefectly normal.