I'm not down with ICV

[yurisuika]

So, tonight my ICV (or something) has decided to start playing around with other parts in the system, and I am not happy with it.

It was a cold, wet night — colder than usually for around here, but still above freezing. I had just made a stop to acquire some contact cement to repair the back seat leather that tore along the seam while I was doing the final touches of installing my new 6x9 speakers. I was just backing into a spot at the store when my car died on me. it just never ends, does it?

At first I thought I had a momentary lapse and forgot to depress the throttle enough while pushing in the clutch. However, this was not the case. Repeatedly the car would die trying to start off on moving backwards. I gave up on trying to back into the spot and moved forwards towards the spot across the lane. The car still died then.

Immediately, I went to my trusty search engine of choice and came up with the answer: it was the ICV. I then moved on to Doug's Domain and took on the task of learning what needed to be done. I read about the different failure scenarios and was pretty confident that it was not the electrical motor... I had just replaced my battery that had been dying nary a few months prior and the alternator got a clean bill of health from the roadside rescue that arrived rather late after I had already gotten the car to start up again. I noticed no blue smoke this cold night (just a little exhaust condensation shortly after the cold start). Still, I took precaution, and after finding myself able to run the car around the lot a bit I took to the road slowly and only stopped for a meal and to pick up some throttle body cleaner. It only died after parking again (and once on the road coming to a stop light).

To best describe it, I would say it only dies when the clutch is in and I give it the normal feather throttle that I would when parking. More juice when taking off from a light and it has no problem. It purrs perfectly fine while idling in neutral, but once I put in the clutch, I need more RPMs than usually and sooner than usual to keep her afloat. The CEL came on (which the only other time it has been on in this car was two years ago that the shop had somehow triggered), so at least I will be able diagnose the issue.

So, in the day I will tear it down and clean and inspect those parts of concern. Hopefully it is not much more than something being stuck, but at least the replacement parts are not too pricey. Perhaps someone here has had this same scenario before and can chime in.

Also, if anyone has any recommendations on OBDII software, that would be appreciated. I have a K-DCAN cable already, but I have not used it for diagnostics yet. Something that can turn off the CEL lamp after I've read the diagnosis is what I am looking for... Free is always good!

[BMWManiac]

I wouldn't be surprised if you find a large vacuum leak....tear in a boot, maybe the one to the idle control valve. I bought a smoke machine for $70. I don't know if you've ever removed the intake manifold, but there are a couple small vacuum lines under there that may need to be replaced too.

So, before declaring it the ICV, I would first smoke test, if you can, and if nothing, I would remove the intake manifold, replace all the gaskets, rubber while you're in there to remove the ICV.

[yurisuika]

That is a good possibility too. The boot near the MAF had a tear those two years ago and since it was already at the shop for the exhaust I had them replace it. I've gone all the way up to the block on the other end, but on that end I've yet to go past the throttle body.

Maybe it isn't the ICV itself, and I am by no means certain it is, but it definitely is something related to it.

A smoke machine would probably be a good investment if I had a bunch of cars, but if any part is noticeably sketchy then I might as well go for the replacement that costs less than one of those machines. I'd like to know where you procured such a machine for such a price, but if the answer is eBay then I'll kindly say gently caress off. Been let down with enough sketchy products there, like a LTW splitter made of drywall. If the real ones were not on backorder for a long time then I never would have dropped so much on something unreviewed and being listed as being from the Balkans (although surprisingly being hand delivered from my area; they knew that thing wouldn't have survived freight even across state lines!)...

[BMWManiac]

That is a good possibility too. The boot near the MAF had a tear those two years ago and since it was already at the shop for the exhaust I had them replace it. I've gone all the way up to the block on the other end, but on that end I've yet to go past the throttle body.

Maybe it isn't the ICV itself, and I am by no means certain it is, but it definitely is something related to it.

A smoke machine would probably be a good investment if I had a bunch of cars, but if any part is noticeably sketchy then I might as well go for the replacement that costs less than one of those machines. I'd like to know where you procured such a machine for such a price, but if the answer is eBay then I'll kindly say gently caress off. Been let down with enough sketchy products there, like a LTW splitter made of drywall. If the real ones were not on backorder for a long time then I never would have dropped so much on something unreviewed and being listed as being from the Balkans (although surprisingly being hand delivered from my area; they knew that thing wouldn't have survived freight even across state lines!)...

I've been a shadetree mechanic since I bought my BMW in 2002. Since I love working on cars, there are a handful of tools I should have bought years ago to make my life easier. There were a couple that weren't available that I have now: the Quickjack and this smoke tester.

Yes, it was $70. Yes, I bought it on ebay. Came well packaged couldn't be easier to use. Not everything on ebay is garbage.
https://www.ebay.com/itm/Automotive-...53.m2749.l2649

[yurisuika]

Yeah, I just like to bash eBay because they didn't side with me on the drywall splitter that cracked and fell apart the day after I installed on its first contact with pavement.

Thanks for the link, though. That was nowhere in the top results when I searched. And thanks for the name drop; that lift seems perfect for my situation. My POS red thing from Pep Boys is in worse shape than the Russian Air Force and I've been thinking about getting one of those Daytona jacks, but that looks like heaven. Now I need to find someone who is a Costco member...

[yurisuika]

So I am starting off on figuring out what is wrong (been asleep over the weekend recovering from a cold so I didn't really feel like getting started immediately). Couldn't get any of the OBD software to work with my cable and thought I was out of luck on getting a reading, but my flashing utility can read the DTCs apparently. All of these are from probably two and a half years. Some of those I had already dealt with, some were of no consequence given my setup... but after sitting a couple days and running the codes again after startup, the HFM is what is triggered here. Unfortunately I can only get really basic information with this cable, but it still is a start.

MS41_Quickflash_v2_2020-01-13_07-24-55.png

Now to take it all apart and clean it out. I should have gotten some MAF cleaner that night, oh well. I guess a good start is to go back to a more stock-ish ROM as well, at least for now.

EDIT: Well, I am just going to call it here. This has to be it. The hose from the post-HFM boot to the ICV was disconnected and cracked. It is possible it was still attached before I started taking things apart, but I'd wager that it had been cracked and that night was when it finally fell off. Makes perfect sense. Preemptive case closed!

20200113_075303.jpg

Still gonna take it apart and clean everything out though, I did buy the spray after all.

[Cos270]

So I am starting off on figuring out what is wrong (been asleep over the weekend recovering from a cold so I didn't really feel like getting started immediately). Couldn't get any of the OBD software to work with my cable and thought I was out of luck on getting a reading, but my flashing utility can read the DTCs apparently. All of these are from probably two and a half years. Some of those I had already dealt with, some were of no consequence given my setup... but after sitting a couple days and running the codes again after startup, the HFM is what is triggered here. Unfortunately I can only get really basic information with this cable, but it still is a start.

MS41_Quickflash_v2_2020-01-13_07-24-55.png

Now to take it all apart and clean it out. I should have gotten some MAF cleaner that night, oh well. I guess a good start is to go back to a more stock-ish ROM as well, at least for now.

EDIT: Well, I am just going to call it here. This has to be it. The hose from the post-HFM boot to the ICV was disconnected and cracked. It is possible it was still attached before I started taking things apart, but I'd wager that it had been cracked and that night was when it finally fell off. Makes perfect sense. Preemptive case closed!

20200113_075303.jpg

Still gonna take it apart and clean everything out though, I did buy the spray after all.

The exact hose was torn on mine! The car was hunting for idle on cold starts (even though it was at the end of last summer) and sometimes the RPMs would dip so low that the car would shudder and nearly stall. Found the faulty hose when I was doing the FLCA ball joints. Replaced it and problem solved.

[yurisuika]

Luckily mine was only torn around the top where the connector is. I used some Loctite adhesive in the two cracks and then bound it in electrical tape and that should hold fine. It is a pain in the arse to get onto the barbed boot connector.


I took off the throttle bodies and the ICV. The ASC throttle body was spotless. The main one had a tiny bit of carbon build up but nothing significant. The ICV was slightly coated inside, but nothing really bad. Hopefully I mounted the ICV back in correctly because I had a hell of a time trying to align the bolts and can't exactly see what is going on under there.


I have a feeling that I loosened it when I was last topping off my leaking power steering fluid reservoir. So now I am about to flash my tune back on now that I found out what had to have been the problem, and if I don't say anything else then that will have solved it.

[BMWManiac]

This is why I always recommend a smoke test :-)