Cadillac Repair: rough idle, fuel pressure regulator, backyard mechanics

Question
QUESTION: I have 95 Eldorado ETC. The mileage on this car is 106,000 In Nov it started to have an idle problem. Very rough it has goten worse. Now when im at a light the idle starts to race then goes low there is a noise from the gas pedal. When I put it in neutral it idles fine. When the car is shut off there is a clicking noise from the gas pedal which has been going on before this idle problem. Any help would be grately appreciate. Thanks, Lorraine

ANSWER: Lorraine,
Sounds like the ISC (Idle Speed Control) is either bad, or WAY out of adjustment.

---------- FOLLOW-UP ----------

QUESTION: You recently answered my first problem and I replaced the motor for the idle control. My question now is the repair was done but the idle is still rough goes low low and them goes high. Why isnt the car idleing like it used to anymore. I love the car but its seems there are problems one after another with it. I cant afford to replace it it did run beautiful before this problem started. I just want the car to idle smoothly , I dont feel confortable with how it ran since it was fixed. Thanks again for you help.

Lorraine

Answer
Lorraine,
Who replaced the ISC? Was it someone that is aware that along with the R&R, there's a few adjustments that must be made for it to work correctly? I've seen many backyard mechanics simply swap the parts and think they're done. NOT the case on this cars. If the adjustments were done properly, I'd start looking for a vacuum leak or possibly a bad fuel pressure regulator.  These are simply two points to check that tend to be fairly common on your car. You're looking for something that's affecting your fuel control. Verify whether the system is running very rch, or very lean.