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Rough Idle


slarti

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I occasionally have a rough idle, sometimes it happens a start up, sometimes at a light. It's only happened a couple of times.

I live in Chicago, and one of my friends (a mechanic) suggested that the ECU is just adjusting to the change in temperature, pressure, and humidity.

Could that actually be the cause or should I be looking for another cause?

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Intermittents are hard to nail down. The ECU is "usually" not the cause of rough idle. Dirty Throttle body, Idle air motor, plugs, cap rotor, coil. The list is long and parts can be thrown at the car but if it's intermittent and not predictable it's hard to know if something you put on the car fixed it.

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Hey it could be the ECM. Slarti where in chicago are you? Man I'm close to you, I'm in north easter illinois, by the border of illinois. Anyways, it is possible that it is your ECM (engine control module) the motronic 4.4 upgrade should rememdy this. here is the link with more info, I hope this helps, I know it is what is causing my rough idle problems, being that it is intermitent(exactly what I'm having) I would say it is the ECM, that is why i don't think it would be the throttle body, last time I had that problem it wasd all the time. Those are just my expeiriences...

and here is the link.

http://brickboard.com/AWD/index.htm?id=776419

Good luck

peace

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I had my throttle body cleaned about 10-15K ago, and I've got new plugs and my wires are only about 10K old.

Where is the idle air motor? maybe I'll try that.

Also is it worth replacing all of my vacuum lines with silicone hose? Could that fix it?

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On a car aproaching 9 years it is a good idea to replace lines, but that might have nothing to do with your problem. The idle air motor is under the black cover for the throttle body pulleys. It's the silver cylinder about 4 inches long, and has two hoses, one coming out the top and going into the vacuum tower, the other out the bottom and connecting to intake of the throttle body.

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If the hose will fit the connector good, even if it's not real snug you could clamp it, then you can loose the elbows.

Hard to check the idle air motor, if it's working most of the time, they do get real diry in there, you will see when you take it out and look at it.

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