my car is a 1985.5 944 with a 1991 S2 engine.
so when im driving and put the clutch in, the rpms go down like they should but they keep falling down past normal and almost to zero. sometimes it will fall to zero and stall and sometimes it will fall to zero and then jump back up higher than normal (normal being about 900rpm). so basically everytime i want to come to a stop, my car stalls or has a crazy idle as if its starving for fuel or something. also the oil pressure gauge drops and rises along with the idle, sometimes dropping to 1. sometimes when i start it up, the idle is weird like this too where it will hesitate and drop, so its not just while im driving. any suggestions? could it be running to rich maybe? i did a little research, but im not sure what it is. these are my thoughts on possibilities:

mass air flow sensor
fuel pressure regulator
vacuum leak
dme
idle stabilizer valve
throttle body
oil pressure relief valve
speed reference sensor

just some thoughts from doing some research, but any help is appreciated thanks!

 

Veify the idle switch in the TPS is making contact. (http://www.clarks-garage.com/shop-manual/fuel-06.htm)
Verify the TPS is properly adjusted. (same link as above)
Check for vacuum leaks. (pressure test, vacuum test, or smoke test)
Check for proper throtle plate closure. (throtle plate should ALMOST close fully at idle, air bypass is by the throttle body screw and Idle stab valve.)
Verify Fuel pressure. (gauge on rail while running, and leakdown over time after shutdown)

 

thanks for the help, but i went out this morning, after not driving the car for about a day, and it started up fine and i took it out and it ran completely normal. idled at 900rpms, didnt stall or even fall below 900. although it idled at about 1100rpms when i first started her. does this mean anything? its an intermittent problem i guess, but i just dont know when its going to happen. thanks