Author Topic: Yet another funky idle issue (Read 5212 times)

mgold · « **on:** January 06, 2007, 06:14:20 PM »

Sometimes, and I mean sometimes, when I come to a stop, the car will bog down and almost stall. The most noticible time is immediately after getting off the highway after coming back from work. Most other times, its hit and miss, but 80%+ of the time it idles normally at around 800 RPM. I don't notice any unusual noises under the hood (like a vacuum leak), and the Check Engine light has never come on. The plugs, alternator have been changed, and my K&N drop-in has been cleaned to no avail. Any ideas? Like I said, the most noticible time is the first stop immediately after getting off the highway after a brisk drive. I've heard ICV and O2 as possible culprits.

E30own'er · « **Reply #1 on:** January 06, 2007, 08:12:26 PM »

maybe your running alittle lean and need to adjust the throttle to be open slightly to alow air to flow when the throttle is closed

m42 fan · « **Reply #2 on:** January 06, 2007, 11:56:14 PM »

If you haven't cleaned out your ICV recently, now would be a good time to give it a shot. I had a similar problem, and hitting the ICV with some Throttle Body cleaner took care of it.

Brian

mgold · « **Reply #3 on:** January 07, 2007, 04:01:24 PM »

Thanks, I'll check the ICV when I have a chance...busy, busy at home (and the garage is like an icebox right now).

e9nine · « **Reply #4 on:** January 07, 2007, 08:35:54 PM »

In my experience, afm, ICV, TPS all affected idle.

One time it was odd that a disconnected ICV actually let the car run right :confused: Turned out to be the TPS in that case. Another time it was just a cruddy AFM which became righteous once cleaned out

Have fun and keep it simple with attention to detail on the AFM boot and your vacuum lines as well while you're at it.

Alpine003 · « **Reply #5 on:** January 08, 2007, 10:02:12 AM »

Quote from: mgold;17062

(and the garage is like an icebox right now).

You guys are weaksauce out in Cali. Try doing a motor swap in 20 degree weather.

Your symptoms sound the same when I had a bad O2. Have you tried checking your codes yet?

mgold · « **Reply #6 on:** January 19, 2007, 12:26:27 PM »

Issue seems resolved. I pulled out the ICV and cleaned it and lubed it with WD-40.

On a related topic...last night at our CCA chapter meeting we had the service manager from the local BMW dealership come speak. He discussed the benefits of running Top Tier gas, but also discussed the importance running gas without ethanol (In California, Chevron is the only gas that meets both criteria year round). Ethanol is very bad for BMW engines. He also recommended running the highest octane available (for us its 91), this is especially important for cars, like ours, without knock sensors to help retard the timing. Now that the ICV is clean I'm going to start running Chevron Supreme exclusively instead of occasionally as I had been (I had been using all different brands: Chevron, Shell, 76, Arco... 91 octane).

kowalski · « **Reply #7 on:** January 20, 2007, 03:12:15 AM »

Quote from: Alpine003;17142

You guys are weaksauce out in Cali. Try doing a motor swap in 20 degree weather.

Your symptoms sound the same when I had a bad O2. Have you tried checking your codes yet?

Trying doing a motor swap in 13 degree weather with 12 inches of snow:) and yes, this was outside!

mgold · « **Reply #8 on:** January 20, 2007, 07:47:46 PM »

Quote from: kowalski;17868

Trying doing a motor swap in 13 degree weather with 12 inches of snow:) and yes, this was outside!

yeah, yeah... I spent 4 years going to school in upstate New York (Syracuse), I know all about working on your car in the cold and snow... lake effect snow to be exact. Unfortunately, since moving to California I got rid of all of my stuff from LL Bean

Vladi · « **Reply #9 on:** January 21, 2007, 05:30:05 AM »

Quote from: mgold;17848

Issue seems resolved. I pulled out the ICV and cleaned it and lubed it with WD-40.

On a related topic...last night at our CCA chapter meeting we had the service manager from the local BMW dealership come speak. He discussed the benefits of running Top Tier gas, but also discussed the importance running gas without ethanol (In California, Chevron is the only gas that meets both criteria year round). Ethanol is very bad for BMW engines. He also recommended running the highest octane available (for us its 91), this is especially important for cars, like ours, without knock sensors to help retard the timing. Now that the ICV is clean I'm going to start running Chevron Supreme exclusively instead of occasionally as I had been (I had been using all different brands: Chevron, Shell, 76, Arco... 91 octane).

Um, The 91 octane fuel you have corresponds to another octane number in Europe? Like, 95 for eg? Our lowest here is 95 and also have 98,99,100. Personally i've always used only 100 octane.

AL GReeNeRy · « **Reply #10 on:** February 14, 2007, 04:55:41 AM »

exactly wheres the ICV in the engine bay?

1991 E30 M42 · « **Reply #11 on:** February 15, 2007, 05:32:51 PM »

Behind the Intake manifold , up against the firewall, and its secured by the lower right hand corner manifold nut.

Eurospec · « **Reply #12 on:** February 15, 2007, 08:28:30 PM »

Could someone explain the cleaning procedure? Squirt TB cleaner in both ends and let dry, is this correct?

FL318is · « **Reply #13 on:** February 15, 2007, 08:33:14 PM »

Quote from: Eurospec;19603

Could someone explain the cleaning procedure? Squirt TB cleaner in both ends and let dry, is this correct?

That would be great! I break stuff.

Eurospec · « **Reply #14 on:** February 15, 2007, 08:36:36 PM »

There's nothing you could break.... easy as pie.