E36 Rough Idle - May Be Running Rich Then Lean...

[Seros]

Hi all,

Been doing as much research as possible before asking on here, but I have an 94 e36 318is which has been playing up for some time with the idle.

When i start it up either when it's hot or cold it sometimes runs roughly and wont keep idling, it will just konk out. I need to pump the gas to keep it going. It just had a full sevices and it continues to do it, plugs and all. I took it to another mechanic and he said it seems to be running rich, then lean depending on how it feels...

I have just replaced the Coolant Temp Sensor but that didnt help, does the car's computer need to be reset when a new part like that is replaced?

Could it be another sensor? If so which ones? Any other ideas?

Thanks for your help.

l.

btw. the car has done 150,000k's

[jrhaile]

have you checked the obvious? fuel filter or pump? sounds like it could be either or. Also the rough idle could be caused by a bad o2 sensor, clogged ICV or vacuum line.

[sennis]

Hey there,

I had the same problem...

Is your check engine light on? If it is, read the codes...

Do you notice you've been getting poor gas mileage? I had an idle which went up and down, and a check engine light...

I cleaned the ICV out ( check out the FAQ - furious posted it.), and I now have a rock solid idle...

The swap in 02 sensor (located under the car right before the CAT) gave me better performance, better mileage, and a cleaner smelling exhaust...

I reccomend cleaning the ICV first, then if problem persists, look at swapping 02... should be done every 30,000 miles or so anyway... It would be a good thing to do... of course check your hoses first... This goes without saying... Good luck

Cheers,
Steve