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Registered User
Join Date: Jul 2011
Posts: 3
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scary high idle and starting issues!
1995 318ti 5-speed...135,xxx miles.
About 50% of the time the car will have a very high idle. Somewhere between 1600-2300rpms. It only does this for a few minutes at a time, then it will return to normal. WHen the idle is high, I can get it to drop down sometimes if I blast the A/C. If I hit the gas while it is idling high, the car will choke up, but then resume acceleration. Its almost like a stutter. If I shut the car off while it is idling high, it will have trouble starting. I can smell gas when I am trying to crank it over and get it to start. Sometimes it takes nearly 60 seconds of cranking for it to start. I have been getting poor gas mileage, and the idle is typically not steady. Anybody have an idea what could be causing this? I am thinking I should replace the O2 sensor, TPS, and maybe the idle control unit. I wante dot check here with you guys first. |
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07-19-2011, 03:51 PM
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Registered User
Join Date: Jul 2011
Posts: 3
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Also...the CEL has not illuminated even one time. This typically happens once the car is warm as well.
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07-19-2011, 03:55 PM
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In the shop at Pelican
Join Date: Aug 2002
Location: Los Angeles, CA
Posts: 10,459
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You have a vacuum leak somewhere in the system. Take the idle control valve out, clean the mechanical portion and then start check ing for leaks.
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07-21-2011, 09:05 AM
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Registered User
Join Date: Jul 2011
Posts: 3
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Jared,
Thank you for the reply. I did the stomp test and got code 1234. It spit this code out 70+ times before I got to tired of sitting there. 1234 Speedometer "A" Signal This code is generated when the engine is under load, over 2500 RPM and no discernable speedometer signal can be detected for more than 10 seconds. Check the wiring harness, and also the instrument console. I will check for vacuum leaks this week. Anything else I can check now that I have read the codes? |
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07-24-2011, 04:47 PM
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Registered User
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You probably have tried this, but check the short vacuum line between the intake manifold and the fuel pressure regulator. If this has a leak or is blocked, or kinked, it will cause a high idle and not show up in the DME as a check engine light...there is no electrical connection. Also, if you take the line off the pressure regulator and you find fuel in the line, the regulator has failed. It has a bellows inside the opens the fuel return valve when vacuum is applied. If this bellows is broken, the vacuum will suck fuel into the manifold. Good luck!
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07-25-2011, 11:09 AM
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