[JerseyBoy]

I bought a new ICM from German auto parts and it's not a factory Bosch unit. Well my problem is my tach jumps. My old ICM didn't effect my tach

. Has anyone heard of this before?

 

[Andy Bro]

Re: ignition control module (JerseyBoy)

The tach jumping is as a result of a poor ground. On my 16v I have a loose ground, and if I have shake the ground while the key is on, the engine doesn't even need to be running, and the tach goes crazy. Maybe when you replaced the module you accidently moved one of the grounds.

 

[JerseyBoy]

Re: ignition control module (Andy Bro)

Thanks for the response. I checked for loose grounds and all were good. I even up graded to 4ga. I replaced the ICM due to intermittent no start. For the heck of it i plugged the old one up and the tach doesn't jump. I guess the aftermarket ICM is the problem. I guess I have to replace it with a Bosch Unit.