A Idle Water Slide Valve Conundrum... HELP?!?!

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TheWolfman
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Tue May 21, 2019 10:13 pm

So here's the rub:

My pre-facelift 1984 320i L-Jet E30 is having some high-idle issues ever since I've got my hands on her.A while ago I visited a local independent BMW 'specialist', who informed me that the only way to solve the issue was to get the replacement illusive 'Idle Control Valve/Water Slide Valve', having finally got hold of one I am now ready to replace the existing one in my beemer. You can see the said items in the pics below....although you may have difficulty distinguishing which one is the replacement one! :mad:

IMG_1860.JPG

The thing is...after giving it some more thought and not really knowing whether the replacement is going to be anymore functional or reliable as the one thats in already in there I have become somewhat hesitant and also questioning whether this will actually solve the issue at all. What got me thinking was as I was looking at the valves I realised both where in the same position, which I'm assuming is 'open' as they are both 'cold'. Now should the one thats already in the car be malfunctioning it would be reasonable to think that it wont actually 'close' when the engine warms up and that the engine would have a problem when warm , this however is not the case...the idle seems fine when the engines up to temperature - about 1200 RPM.

To summarise the issue:

  • On cold start the engine revs rise slowly over about 20 seconds to about 3000 RPM
  • The engine has the occasional 'cough' here and there where it seems to either misfire and rev's drop very momentarily, very slight rev fluctuations and the occasional jolt
  • The engine seems to be running quite rich
  • Starting is somewhat unpredictable, sometimes starts straight away and sometimes needs to turn over a few times before starting.This does not seem to matter whether starting from cold or when warm.It does however ALWAYS start... :P

I'm starting to think that the issue is one of either a vacuum leak maybe alongside a TPS issue, also maybe the injectors being leaky.

TPS has definitely seen drier days!:

IMG_1848.JPG

I'm going to test it and see how it reads out however.

I'm just wondering if anyone had any thoughts or experience on these issues and this bloody valve?
TheWolfman
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Tue May 21, 2019 11:20 pm

The other scenario with the valves is obviously also that they are infact actually both already 'stuck' as they are in the same position and thus it is actually the reason why it has a cold idle issue.If this is the case though,I would presume that the replacement valve will also be an issue as it is in the same position and thus effectively also already stuck?

I expect I'm not probably going to get much response on this one as it's only a lowly 320! Gotta say though..I LOVE how smooth the engine is and particularly how it sounds,well..when it's warm anyway!

I'm really at the edge of my mechanical knowledge here, but everyday's a schoolday as they say.....
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aimlessrock
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Wed May 22, 2019 8:46 am

if your looking to keep the car i would be minded to upgrade to Motronic 1.3

https://www.e30zone.net/e30wiki/index.p ... tronic_1.3

After reading the list half of these i have in my stash.
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
TheWolfman
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Wed May 22, 2019 10:23 am

That is something I've actually considered before and may well be a future upgrade and I'll definitely be hitting you up to see if you've still got some of those bits in the stash :wink:

For now though I just want to work with what I've got and hopefully sort this idle issue.I'm hoping someone on here might have some additional wisdom or experience with this poxy valve!

One other thing I also considered was just upgrading the Water Slide Valve to a modern Electronic Idle Control Valve, which can apparently be done according to this:
ICV.jpg
ICV 2.jpg
The main decision I need help with right now is whether to actually fit the replacement one I have and ascertain whether it is actually the Valve that is causing the Idle issue :mad:
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aimlessrock
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Wed May 22, 2019 12:24 pm

I have one of them off in my stash also if you need one mate.
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
TheWolfman
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Wed May 22, 2019 10:50 pm

I'm pretty certain that the TPS has definetly been part of the Idle problem at least, tested it with multimeter and was completly unfunctional, opened the sucker up and this is what it looked like inside...absolutely soaked in oil.
IMG_1865.JPG

I gave it a good clean up and now it appears to function properly, all contacts give correct readings.I also decided to drill a little hole in the bottom of the TPS casing so that any oil that finds it's way in there dripping down the butterfy assembly will hopefully drip out.

IMG_1869.JPG
TheWolfman
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Wed May 22, 2019 10:51 pm

Respect AimlessRock, might end up going down that road - probably sooner rather than later! So that's appreciated
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aimlessrock
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Thu May 23, 2019 6:00 pm

Nice work. How are the injectors looking btw?
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
TheWolfman
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Thu May 23, 2019 9:20 pm

Thanks man.Not had a chance to open that particular can of worms yet, busy rebuilding drum brakes and lines...which was unexpected...

Will get around to to having a nose at the injectors relatively soon though hopefully.
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aimlessrock
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Fri May 24, 2019 7:38 am

Pull them and have them overhauled - search for one of the traders-injectortune, he rebuilt and balanced all of mine for something like about £10 per injector, but this was about 3 years ago.

No brainer
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
TheWolfman
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Fri May 24, 2019 7:46 pm

Cheers for the heads-up.I looked into injectortune, seems like a fairly priced good service, I'll definitely get them over to them when I get around to pulling the things out, everything's going to get an overhaul at some point along the line.
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