Cadillac: Cold Start and High RPM Idle Problem, exhaust gas recirculation valve, exhaust gas recirculation

Question
Have 1994 Eldorado with 170K miles.  Car runs fine except for the high RPM idle (900 to 1100 RPM).  Car does not decelerate when I take my foot off the accelerator.  Also when cold starting the engine does not fire smoothly for the first 30 seconds.  After that it is OK.  Checked OBD and found nothing of significance except for a code PO 30 (RPM out of range).
Would appreciate your help!

Answer
You could have a faulty ISC (Idle Speed Control Motor), An intermittent fault in the tps (throttle Positioning sensor) Or somebody turned up the base idle screw which is a NO-NO. You may just have to service the throttle body and the EGR (Exhaust Gas Recirculation) valve and passages.


You will need to contact me at:


tomcjoy@msn.com


In order for me to provide you with pictures and and electrical schematic to find and fix your problem since this board does not allow sending pictures.

PLEASE include your original question(s) and the MAKE-MODEL-YEAR and ENGINE SIZE of your vehicle when you contact me.

PLEASE tell me if you do your own repairs and or your skill level of auto repair. This is VERY VERY important if I am to be able to help you repair your own vehicle.


tom