gbailey911

My 1987 911 coupe has recently developed a intermitent fast idle. Sometimes after warmed up, the idle will hang up at around 1000-1100 rpms and will require a quik blip of the throttle to get it to return back to it's normal 800 rpm idle speed. Does anyone know an area I should check for any hang-ups or necessary lubrication in the throttle linkage to correct this annoyance?

Thanks in advance,

George

scottb

Mixture?

rbcsaver

Are you using an oil based air filter by any chance? Remove the air filter and try spraying air intake cleaner (not carb cleaner) directly in the air intake/sensor. Helped to solve my 84's idle issues.
regards,
Steve?

gbailey911

Steve, I am using a K&N filter, I know it was cleaned and recharged late August so I don't think the filter is the cause but the sensor could be. I will try cleaning the sensor like you suggested.

Thanks,

George

rbcsaver

George,
If the filter is re-oiled and not allowed to set-up (the carrier volatiles evaporate) or is over-oiled, purple oil will migrate into your air intake, coating the componets. This has been a discussed problem on the forums. Do a search. Let me know how you make out with the spray air intake cleaner. Again, do not use spary carb cleaner, but spray air intake cleaner.

gbailey911

Steve, I sprayed the air intake cleaner into the intake system on my car Friday and as far as I can tell, the problem has disappeared. I also installed one of Steve Wong's performanace chips the same morning so I have been re-experiencing my new-found performance this week-end.

Thanks for responding to my post and for the advice that corrected my idling problem.

George

Lorenfb

You need to check the idle switch on the throttle body. It may be intermittently
staying open. Use an ohmmeter for the test.

gbailey911

Loren, one of the first things I did when the idling problem started was check the micro switches as suggested by Steve Wong from 911chips. The switches both work correctly. I think the problem was fixed with the air intake cleaner.

Thanks for the post.

George

rbcsaver

George,
As I learned from my own experience, or actually a lack there of, is that frequent cleaning, over-oiling or not letting the oil setup is not good and that purple oil will migrate into the intake with the air. **Perhaps** others are right in not recommending use of other than OEM paper filters.
regards,
Steve