Hunting Idle--Stalls

[Fassi]

Hi,

The idle on my friend's 1988 325i is not steady. It seems like it might die, then suddenly the car will rev (this is probably the DME trying to keep the car from stalling), followed by a return to the low idle, and so on. Usually the car does not stall completely, but it has done that as well. This is accompanied by a fuel odor.

The car will also stall while moving, usually at low speeds during the 1-2 shift range.

I should note that she has a very low (way too low--PO's "upgrade") suspension and that the car recently took a pretty good blow over a nasty pot hole which resulted in a grinding noise from the passenger side rear of the car at low speeds, particularly while turning. The sound is not as obvious at higher speeds. I don't know if this could be related.

This seems to me like a fuel issue--maybe the fuel pump--or a problem with the ignition--cap, rotor, plus, and wires.

I used to own a 325is, but I don't have a lot of experience with the mechanics of these cars. I would appreciate any advice you could offer me.

Thanks!

[Jared at Pelican Parts]

Ok, first off this can be a couple of things.

1. Check all vacuum hoses for leaks. EVERYTHING. even the valve cover gasket. If there are any leaks, it will cause the idle to fluctuate.

2. Throttle Position Switch. Over time, the switch gcan go out of adjustment and cause the idle problem. I have seen numerous cars with idel problems fixxed by merely re-adjusting the switch.

3. Oxygen sensor or coolant temp sensor, if both of these are faulty, it can cause a wierd idle, but not usually.

If you send me you email address, ca send you some articles which go over the system and how to repair the problem.

[bmw4ricky]

I cleaned the valve- no better. Then I adjusted it, the idle rose, still kinda spuratic, but ussually above normal rpm idle so it was driveable. It's been 2 months now the thing bucks and stalls. Should I just buy a new valve, or is it not the valve and something else? Any help? -thanks Rick

[Jared at Pelican Parts]

How did you adjust it? How did you clean out the valve?

[bmw4ricky]

I decided to take one last look at it before I bought the valve. The air flow boot was slit on the bottom. I only noticed because I rested my hand on it. The engine setled out smoothly, the shimy stoped, the exhaust shut up, and as you can imagine I am very happy. -thanks for the help- Rick

[Jared at Pelican Parts]

There you go. Glad to be of help.

[bmw4ricky]

even though that tube is fixed, now the engine stops under full throtle. I'm guessing this is because of the mixture being adjusted, how do set it up to normal again, I can get the idle back down to about 1000 but it used to idle at 500, thanks for any help- Rick

[Jared at Pelican Parts]

Im confused. You cant adjust the mixture on that car. How did you do it? I'd need to know this. If you did what i think you did, you may hae damaged the fuel injection.

[bmw4ricky]

I'm pretty sure thats what I did. Its a screw on the idle control valve. You can tighten or loosen it, directly affecting the idle. I loosened it, raising the idle another 500 rpms. After I fixed the tube I screwed it as tight and the idle once again lowed to its old 500. Still I am getting this full throtle and close to full buck back fire stall result. At this point I'm sure I screwed it up, I'm just trying to figure out where. I think or hope I just broke the valve.

[Jared at Pelican Parts]

This car is an 1988 model, right? If so, then you have the wrong ICV on there. it is supposed to be non-adjustable. can you get a part number off it?

[Jared at Pelican Parts]

Can you get a picture?

[bmw4ricky]

Its an 86 325e

[Jared at Pelican Parts]

ok, completely different thing then. At the top it says it is a 1988 325i

how did you adjust the switch? Did you check for resistance?

[bmw4ricky]

no, I just loosened itthen tightened it all the way down after i fixed the tube. A friend is sending me a used one. It'll be here friday, so im hoping that will fix the problem

[Jared at Pelican Parts]

did you adjust the throttle switch? This is different from the idle control valve

[Jared at Pelican Parts]

the throttle switch is on the side of the throttle body and controls the operation of the idle control valve. If it is out of adjustment it will cause this problem.

[bmw4ricky]

No I only adjusted the air fuel, i figured that valve was the problem, so that is the only thing I messed with. Although it could be that I have a completely new problem that is not related, I'll know friday when I have the part

[bmw4ricky]

I replaced the part. Same problem. I just had all the filters and everything checked and replaced 2 months prior by a mechanic who owns a repair shop, a friend of mine for $1000 which only covered the parts at his cost. The car has hartge rims, m gear shift, dinan chip, side skirts, and power moon roof, only 120,000 on it. I would really like to keep it. I'm in South Carolina though, and the dealership is the only place around, so I'm afraid the repairs will be to high. ANY HELP PLEASE? - although the Minis are nice I'd rather keep the one I have, but I'm tired of paying these repair costs

[Jared at Pelican Parts]

Look, did you adjust the throttle switch or not? Even if you put a new on on there, it still needs to be adjusted

[bmw4ricky]

I adjusted the idle mixture only, that is all that i messed with. I have adjusted it in every single way to see if it would fix it, but no it's still messed up. here is the part i am specificly talking about: http://catalog.pelicanpartsexpress.com/pelican/detail_test2.jsp?partner=pelican&clientid=pelican&baseurl=http://www.pelicanpartexpresss.com/&year=1986&make=BM&model=325-ES-001&category=C&part=Idle+Control+Valve

-thanks