Erratic Idle Fix

[snoopy325e]

Hi all...

Firstly I must say this a great resource to have on hand.

Anyway.. I have been having a few issues with my 86 325e in terms of shuddering and idle/surging problems. I finally found the shuddering which was in fact the right engine mount under the exhaust manifold had completely delaminated into two halves and the left one wasn't far befind in terms of damage. After a trip to Mr BMW parts and a $100 later she is shudder free.

Idle problems were fixed by removing my ICV and cleaning the sucker. I have read numerous faq's on the subject of which some say don't clean it and others recommend cleaning. Well after you would have seen what came out of the ICV its no wonder I had erratic idle. I connected the ICV to a 12v power supply in my workshop to check current draw which should be around 1.2amps when not connected to the ICM. Tests showed I had around 1.3amps and she was a little slow and sticky, so while powering the valve to hold it open I put a little carb cleaner in there and with some q tips I think thay are called in the US, I cleaned her out again and again. After each clean I switched the power off and on to the valve to get the grunge off of the main plunger contact face and cleaned it again with lots of carb cleaner spray to flush the debris out after which she now sits at 1.2amps.... My idle is now better than ever and is rock solid, yehaa.

I also have a surge at part throtlle which I am chasing.... but didn't notice it on the test drive after cleaning the ICV, which doesn't make sense at all.

Cheers...javascriptticon('')
smilie

[joshh]

Good to hear!!

Do you have a sheild over the motor mount on that side?
One of my E-30's does and the other does not.

[woolness]

Good work!

But what is your ICV and where is it? I have the m42 engine 1991 e30 318is. I have had a bit of a idle problem too and thought that I should give her a go too....

cheers

R.

Originally posted by snoopy325e@Apr 16 2005, 05:24 PM
Hi all...

Firstly I must say this a great resource to have on hand.

Anyway.. I have been having a few issues with my 86 325e in terms of shuddering and idle/surging problems. I finally found the shuddering which was in fact the right engine mount under the exhaust manifold had completely delaminated into two halves and the left one wasn't far befind in terms of damage. After a trip to Mr BMW parts and a $100 later she is shudder free.

Idle problems were fixed by removing my ICV and cleaning the sucker. I have read numerous faq's on the subject of which some say don't clean it and others recommend cleaning. Well after you would have seen what came out of the ICV its no wonder I had erratic idle. I connected the ICV to a 12v power supply in my workshop to check current draw which should be around 1.2amps when not connected to the ICM. Tests showed I had around 1.3amps and she was a little slow and sticky, so while powering the valve to hold it open I put a little carb cleaner in there and with some q tips I think thay are called in the US, I cleaned her out again and again. After each clean I switched the power off and on to the valve to get the grunge off of the main plunger contact face and cleaned it again with lots of carb cleaner spray to flush the debris out after which she now sits at 1.2amps.... My idle is now better than ever and is rock solid, yehaa.

I also have a surge at part throtlle which I am chasing.... but didn't notice it on the test drive after cleaning the ICV, which doesn't make sense at all.

Cheers...javascriptticon('')
smilie

[snapback]333567[/snapback]

[witeshark]

Have you had the catalytic converter checked or replaced?

[snoopy325e]

Originally posted by witeshark@Apr 17 2005, 12:37 PM
Have you had the catalytic converter checked or replaced?

[snapback]333648[/snapback]

No I haven't but a good point none the less.

After driving it all day today at every chance I could get, "oh I gotta go to the shops, again "... The idle seems slow to return to 700.. Although the idle is a lot better I think impending clouds of doom are hovering above my ICV. Another thing I found this morning while searching for problems was I noticed I had the smallest coolant leak (drip) right above the throttle position sensor on the throttle body which after inital warm up was leaking coolant onto the switch and possibly creating havoc. Ah hah, shorting of the throttle position sensor could be the culprit I thought, so I replaced the hoses and cleaned the switch out with good results in that as I test drove the car she had no hesitation at 1000 - 2000rpm. Wow what a day two problems fixed.... So I decided to take my wife for a drive down the coast and there she was the bloody hesitation came right on back.

I think I will get the cat converter checked as suggested.

Will have to wait a while but, as I have spent around $2500 this week alone on my baby.

Must get a pic organised..... cya.