Any idea what would cause the idle of a 1983 244 Turbo to go from 1200 down to 600 at rest? Start the car, let it warm up and about two minutes later the idle goes up and down. I adjusted the idle as directed in the Bently manual, but that didn't stop the problem. Could it be a vacume line broken? What's happening here?

Thanks,

Tell me how you adjusted the idle per Bentley???

I bet you have a sticking CIS motor.

I'm doing this from memory mind you. The Bently book said to disable the CIS system by grounding the unit (blue white wire), then starting the car and adjusting the Idle at the throttle valve, near the small switch. After it is in range, turn the engine off, remove the ground wire, start the car and check if idle is in range.

I just followed the book.

Where is the CIS motor?

How do I test it?

The idle motor is attached to the intake manifold. Kinda under and behind.

Unplug, remove both hoses and unbolt.

Once you have the pup in your hands spray the crap out of it with some WD-40 to get the excess oil out, then clean with PB-Blaster. It should have no gummy hard crap in it. Hook up 12V and watch it snap open and closed as you switch inputs. Mine went out on my 85 245Ti...I put one in from a 262C and it works better than new!!!