1986 325 erratic Idle

[bimmer630]

1986 325. old version (jetronic?) with idle control computer behind glovebox.

-Idle jumps all over, sometimes its fine, sometimes its erratic, sometimes its just hanging out too high, sometimes it stalls



I tried cleaning out IAC, replaced TPS, smoke tested intake and found no leaks, changed out some coolant temp sensors, adjusted base idle speed and mixture while jumping all terminals on disconnected TPS switch.


I even got another Idle control computer and that made no change.

every E30 Ive seen with uncureable idle issues ended up being a DME. but does the DME on these sytems have any affect on idle?

[long tall eta]

idle issues in the early models can be hell to track down. maybe you maf. check your fuel pressure, and fuel filter. take it to guten parts and service

[jaysee]

i have a 86 eta and they are basic motronic, have you tried adjusting the iac?
there is a flat head screw hole on the top by the hose coming from the intake boot
i had a very irratic idle also until i relized there was a adjustment screw wial i was broke down on the side of the road. opened it up a little and everything cleared right up
my idle was up and dont almost to the point where it sounded like it wanted to die