I have always neede to ask this. The GM shop manual says the set the timing at 10* at 675 RPMs. Now...my car still has the factory "plug" covering the idle set screw and has not been changed. My car usually idles at 1000 or 1100rpms. Shoul I remove that plug and set the idle at or around 675 rpms and THEN adjust timing OR leave it at the current idle rpms and set the timing at little higher? I noticed today even after the brake booster was put on, the car cut off as I was taking a turn on a road. Like when you are driving 35 or so and slowed down to take the corner. I don't know if it might be an ignition problem or not. It does'nt stall or cut off at stop lights or anything...just taking a corner sometimes. Maybe the power steering pressure switch? Anyone else have a clue?

Ken

 

Vacuum Leaks are your enemy. If you still have the plug over the idle screw, it's never been adjusted. Removing the plug and messing with the screw is only going to be a bandaid, not the solution. Advanced timing can cause high idle as well as vacuum leaks. Make sure that the throttle plate is closing all the way, just see if you can foce it closed more than it normally does, if not, then you have leaks elsewhere in the intake system causing the high idle. Also check the adjustment on the TPS since an incorrect reading can cause more fuel to be injected and that will raise the idle speed too.