List of Erratic Idle Causes....

[b*saint]

Really? The 153's have bad idle fuel maps or something?

[Mless5]

fuel pump.

[formula driver]

Would a crank position sensor have anything to do with an erratic idle???

[bddog]

Bad intake boot. It can look good from the top and still be shot .
The preformed hose from the throttle body to the idle control valve.
If you are fed up and serious about fixing the problem buy a new boot . new hoses and a brand new idle control valve.
These are items that just wear out and need replacing .
I played the idle game .
Ever since I bought a brand new valve (not cheap) and all new hoses boot etc. , she idles like a kitten.

[Gussy]

Idle control valve or cracked intake boot would be the more common causes.

[formula driver]

Idle control valve or cracked intake boot would be the more common causes.

These are the easy things to check, I would hope this fella has checked these things already.

[Adrian_Visser]

well this isnt a real fix by anymeans but you can change the adjustment on the icv itself. if you have a silver one the screw is on the outside, a black one the screw is on the inside behind where the hose from the intake boot connects on. counterclockwise speeds up, clockwise slows down. it takes more than one full turn to do anything though so dont be surprised when nothin happens at first.

my idle used to be so fuckered. it would jump up to like 1750 then the ecu would cut fuel and it would fall to 1000 then back up again over an over (WD 40 IS BAD FOR ICV'S!!) so i got fed up and cranked the screw down. now it jumps around a bit between 7 and 8 hundred when its cold but its much better thatn before

[Adrian_Visser]

here's a good link about fixing idle problems i got it from unofficialbmw.com

http://www.verrill.com/car/e30_idlefaq.shtml

[formula driver]

well this isnt a real fix by anymeans but you can change the adjustment on the icv itself. if you have a silver one the screw is on the outside, a black one the screw is on the inside behind where the hose from the intake boot connects on. counterclockwise speeds up, clockwise slows down. it takes more than one full turn to do anything though so dont be surprised when nothin happens at first.

my idle used to be so fuckered. it would jump up to like 1750 then the ecu would cut fuel and it would fall to 1000 then back up again over an over (WD 40 IS BAD FOR ICV'S!!) so i got fed up and cranked the screw down. now it jumps around a bit between 7 and 8 hundred when its cold but its much better thatn before

Cool...thanks man. Ill try it....

[formula driver]

Would a crank position sensor have anything to do with an erratic idle???