Just recently I started having problems with Turbo Timer not keeping my car running when I turn off the key. The engine will either rev up to 3500-4000rpm and then settle down or just die. It doesn't have any idle problems or problems stalling while I'm driving just when I go to turn it off. Anyone else have this problem? BTW: it's a Greddy unit if that makes a difference.

 

first things first....check your ground and parking brake wire.

 

I have a problem like this too. SOMETIMES when park and turn the car off (with the parking brake up) it will rev to 3k rpm and drop down to idle for the 30 seconds before shut off.