Irregular Idle Speed

[nicholas]

My pathy is beggining to worry me; the idle is erratic. When the vehicle is cold and running it usually idles around 1500 - 2000, but when it's warmed up it sometimes idles where I want it (and it should probably be) at 1000. But it never consistently drops down to 1000, most of the time if I've stopped at a red light it'll hover around 1500 rpms. It's kinda weird though, it'll drop to 1000 then creep up to the 1500. Weird.

 

Awhile back the ecu threw out a code 11 (crank angle sensor), would a crapped out crank angle sensor acount for this? If the thing was pooched wouldn't the truck barely run? What about running injector cleaner? Oh and I don't think it's a stuck throttle or anything, cause if I stomp on the peddle a couple a times it still does not drop down to the proper idle.

 

91 SE V6 (4x4)

[MY1PATH]

idle should be about 800 and fast idle(cold) should be 1100-1200. your fast idle screw may be ajusted too far so that its interfering with normal opperation.