WTF idle problem.
The car is a 1986 325es. I didn't have any idle problems before other then it would idle at a steady 1000 RPM's. I took the ICV and fuel jet unit off to check and clean. Cleaned it with a can of brake clean and replaced the vacume hose. Now I have high idle or rev and drop idle. I tried to adjust the screw on the ICV but it just goes from high idle to high and drop. The only way I can get normal idle is to restrict the vacum hose with a clamp. Just looking for some helpful input. I don't feel it's the ICV gone bad because it was fine before I cleaned it and don't understand why just doing a light clean would make it go bad. I didn't replace the vacume hose with an OEM piece. Does the OEM have a restricter in it ? This has me stressed out.
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I have occasional idle/rich running issues on my '86 es too. I was just reading about this very problem in an old copy of Roundel magazine last night. I refer you to the great Wayne Dempsey:
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The first thing to rule out/fix would be intake leaks. A smoke test is the only sure diagnostic. Also check the idle switch in the TPS for proper adjustment and operation.The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, ALComment
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Thanks for the input. Maybe I can some time on it tomorrow if the rain lets up.Comment
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^ that's what I would check first, you can also check your idle control module ( green small box near ecu)Comment
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Wasn't able to check it out much today do to the rain. I did check for an acumen leak in the ICV system itself and didn't find one. I did reclean the ICV and it worked fine for a couple minutes but went back to high idle again. It will rev up if I unplug the ICV. I still have to adjust idle by restricting the vacume hose. I'm not real sure on how it functions. I read something about a plunger inside that restricts vacum to the intake. I may have pushed some junk into it farther from spraying it that may be blocking it from sealing correctly. I'm also not sure on what and how the adjusting screw on the IVC works. Does the IVC inject extra fuel only at idle or threw the full RPM range ? I'm asking this because my engine seems to normally run fine but sometimes it has a real extra boost in power. Looks like I may have to put some work in with the multi meter. I kinda have the feeling something isn't correct and there's more power to be had.Comment
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The idle control valve doesn't inject fuel, only air.Comment
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I know the ICV doesn't but it's connected to a part that does. I'm asking if the ICV also controls the fuel for that injector.Originally posted by NoM54me View PostComment
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I think you're talking about the cold start injector. It's activated by the thermo-time switch, which is a large sensor on the thermostat housing. That injector should only work when your coolant temp is below the specified setting on the sensor, usually 86°F. The ICV and cold start injector aren't connected, but allow air and fuel, respectively, to enter the intake manifold at the same point. They're unrelated otherwise, in fact, the ECU knows nothing about the cold start system.Comment
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I had a bad idle problem too. Where does your temp gauge sit when your car finally warms all the way up? Because mine was sitting in the blue and wouldnt come out of the blue which was telling my ECU that my car was still cold. Changed my thermostat and it fixed my problem. Now my temp gauge sits in the middle and my idle is perfect. I did some research and i found out the most common problem for idling issues is the coolent temp sensor located on the thermostat housing. Its blue i think. Anyway replace that. If that doesnt work, replace the thermostat on your car too. Usually icv dont go bad. So again replace your coolent temp sensor and thermostat. Cheap start anyway
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My gauge just almost touches the first white line. My idle stayed at a steady 1000 RPM till I cleaned it.Originally posted by blizake500 View PostComment
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Change you thermostat and that will fix the problem. Your thermostat is stuck.Comment
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