On occasions mostly when cold, the engine fails to idle and died on several occasions. Proper idle RPM is approximatley 650. On other occasions when hot, the engine wants to idle at 850 RPMs, which is too high. Also it seems that when rolling down the road and I took my foot off the accelerator, the RPMs stayed too high, as if the Accelerator were sluggish or sticking. On occasion at low speeds, I had to keep my foot on the accelerator to keep the RPMs up so the engine would not die.
Idle and Accelerator problems. on 2004 Cadillac DeVille
The idle air control valve may be sticking on your 2004 Cadillac DeVille causing an erratic engine speed. Another possibility would be an intake manifold vacuum leak from the seal between the throttle body and the intake manifold. Proper diagnoses will be necessary to determine the cause of your idle problem. Please use the following link to find a repair shop near you - http://repairpal.com/directory?address=95060&car_brand_names=Cadillac.