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  1. #1
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    Member No: 77225 AFARR is an unknown quantity at this point AFARR's Avatar
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    Idle Control Valve or Module problem? (1987 325e)

    I cleaned the Idle Control valve with some carb cleaner, let the car run for about 10 minutes while I cleaned the interior (got to operating temp).

    Suddenly, it started to fluctuate between 800 and 1200 rpm like someone was pushing and letting up on the gas.

    Only happens at park/neutral idle, not in drive.

    Only when warm.

    I did a search on here and took the ICV off entirely, cleaned the crap out of it with carb cleaner (didn't have brake cleaner handy) and finished off with electronic cleaner (dries quickly).

    Replaced.

    Same problem.

    Switched the plug on the back around, tried adjusting the screw both directions..

    Same problem.

    I took the ICV off and double checked it. The part inside slides very easily with a small push of something.

    No visible crud.

    Replace the ICV or Module?

    Any way to do a quick and dirty check (I don't have my volt meter/multi meter handy)?


  2. #2
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    Member No: 6647 modifier is an unknown quantity at this point modifier's Avatar
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    I had the same problem today too!

    Maybe it is the cold weather today but I have had the same problem all day. Cleaned out the ICV and it still does it. I would like to hear any advice too! Oh, I also had a weird thing come up. When I start the car the idle jumps up to 2,500 or so and then comes down (before starting the up and down thing)...what would cause that?

  3. #3
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    Re: Idle Control Valve or Module problem? (1987 325e)

    I have the same problem and it's very common. I am still trouble shooting it. See www.unofficialbmw.com/repair_faqs/idle.html. I did everything he said to do but same problem. Maybe controller is bad or a switch on the thermostat housing one of 4. Thankyou BMW! I'll try something different and reply later if I'm not in a mental institution by then.

  4. #4
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    Member No: 22190 arnoldgtr is an unknown quantity at this point arnoldgtr's Avatar
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    My fix

    I started driving my project car last week. It's a 1984 318i with 184K miles. Ever since I bought it two months ago, it has idled at 1500 RPM, even with the bypass screw fully closed. I did every check in the Bentley, the factory manual, and on the internet. The idle valve passed every test. Resistance was in spec (9.2 ohms), no matter where I positioned the plunger. Applying 12V would close the valve tightly, stopping the engine. The control current was on spec, 470 mA. The valve would buzz at about 150 HZ when the key was turned on. Unplugging the ICV wiring harness would cause the engine to accelerate to 2000 RPM.
    I checked the ICV hoses and all other possible locations for vacuum leaks. I found none. The intake boot was recently replaced.
    I also checked all the inputs to the idle control unit. All of them were in spec. The control unit is the best version, with the olive green case. I opened the case and inspected the components. I found no broken traces or heat damage to the driver transistor.
    I also swapped the ICV and control unit from my parts car, but there was no change.
    Desperate to drive the car to its first BMW CCA meeting, I drilled a #20 hole (0.161") in a penny and inserted it in the intake hose to the ICV. That gave me a steady 880 RPM idle when warm, but the cold idle was too low, plus I had to pad the accelerator to keep it running until it warmed up.
    Saturday, I raided the local junkyard and came home with two more idle control units, plus an ICV from a 1984 528e. After swapping one of the control units and observing no change, I installed the new (old) ICV. Voila! It actually idles in spec. Sunday, after a relatively cold morning, I checked out the cold starting. It's working perfectly now.
    As an aside, with this last ICV, I heeded the advice I read about not cleaning it. The ICV from my parts car was working before the car was wrecked, and the only difference was that I cleaned it before trying it on the project car. It makes you wonder if cleaning the ICV is a good idea.
    HTH,
    John
    88 ///M3 Cinnabar
    84 318i Black

  5. #5
    TannonE30
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    Same Issue

    Quote Originally Posted by modifier View Post
    Maybe it is the cold weather today but I have had the same problem all day. Cleaned out the ICV and it still does it. I would like to hear any advice too! Oh, I also had a weird thing come up. When I start the car the idle jumps up to 2,500 or so and then comes down (before starting the up and down thing)...what would cause that?
    Hey I know it’s been 15 years since this post but worth a shot. You described my exact issue to the point. I’ve replaced the idle control valves. Throttle position sensor and cannot find a vacuum leak. What did you do to end up fixing this issue. Thanks in advance if you see this
    Reply With Quote Reply With Quote 66.87.125.31

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