I have a 2005 Tennant floor scrubber with the GM 3.0L with EST timing. (brought in not running). Performed tune up on unit with plug wires cap and bug. I bought the jumper harness for it so I could set the base timing because the timing was off. I set base timing per spec at 1 degree before top dead center and it runs great with the jumper plugged in but once you plug back up the EST timing the unit wont start and it kicks back on the starter like its out of time. I replaced the module that is inside of the rotor and that didn't help anything. Any help would be very much appreciated!!!