[986] Idle problem
02-23-2014, 12:37 PM
#1
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Join Date: Feb 2014
Location: Göteborg, Sweden.
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[986] Idle problem
The other thread is getting too big since it's only including questions by me bacically.
Main problem:
List of things I've done:
List of solutions I've concidered:
Video of the problem : (I'm really sorry for how the video was recorded. But it was the best way to hold the phone while driving without dropping it.)
With kind regards, Jonathan from Sweden.
Main problem:
- The idle is pending when pressing the clutch / going into neutral when having the aircondition on. Doesn't matter if standing still or moving. Has happened to me while not having the AC turned on, but only 50-100 RPM tops, towards the 700 RPM drop with the AC turned on.
- Note that this ONLY happens when the engine is warm. (I can have the AC on with no problem until the engine hits 80°C.
List of things I've done:
- I've claned the throttle body.
- I cleaned the air flow sensor.
- I cleaned the idle sensor located on the throttlebody.
- I tryed replacing the idle sensor located on the throttlebody. (Borrowed from my mates 986)
- I tryed replacing the air flow sensor (Borrowed from my mates 986)
List of solutions I've concidered:
- The AC compressor. - Contacted a porsche dealer, and an expert told me they never, or atleast barly ever replace the AC compressors on porsches, since it's almost always other fualts.
- Battery not taking enought chargeing?
- Gererator or compressor wheel running slow?
Video of the problem : (I'm really sorry for how the video was recorded. But it was the best way to hold the phone while driving without dropping it.)
With kind regards, Jonathan from Sweden.
05-12-2014, 12:40 PM
#3
Race Director
Well, I'll take a shot…
It reads like you have covered all the usual causes.
What is the history of the car? Any mod's? What has been done to it recently? I'm thinking of anything, service, repairs, mod's before you noticed the behavior?
When you cleaned the MAF and idle air valve did you find them particularly dirty? Oily?
When you cleaned the throttle body did you find the throttle body dirty? Oily?
Also, did you inspect the inside of the throttle body and its butterfly valve for any signs of misalignment, excessive play, or even contact by the butterfly valve with the body's inside bore?
If any of the items you cleaned were particularly dirty or oily, that can be an early warning sign of an AOS failure, for when the AOS is going bad it can be an air leak. Early on with my 02 Boxster it was idle speed misbehavior -- hunting idle -- that was the early warning sign of what proved to be a failing AOS.
If you can produce this symptom/behavior with the engine cold and stationary you can remove the serpentine belt and start and run the engine without the belt for a while. Not a long while but long enough to determine if the symptom is present.
If you can do this with the belt removed then this eliminates any accessory drive as the source of the problem.
If the symptom is still present this suggests it is a fueling problem, which could be an intake air leak.
Would be interesting to observe the fuel trims before, during, and after the symptom appears to see if these are showing any indication of fueling trouble.
It reads like you have covered all the usual causes.
What is the history of the car? Any mod's? What has been done to it recently? I'm thinking of anything, service, repairs, mod's before you noticed the behavior?
When you cleaned the MAF and idle air valve did you find them particularly dirty? Oily?
When you cleaned the throttle body did you find the throttle body dirty? Oily?
Also, did you inspect the inside of the throttle body and its butterfly valve for any signs of misalignment, excessive play, or even contact by the butterfly valve with the body's inside bore?
If any of the items you cleaned were particularly dirty or oily, that can be an early warning sign of an AOS failure, for when the AOS is going bad it can be an air leak. Early on with my 02 Boxster it was idle speed misbehavior -- hunting idle -- that was the early warning sign of what proved to be a failing AOS.
If you can produce this symptom/behavior with the engine cold and stationary you can remove the serpentine belt and start and run the engine without the belt for a while. Not a long while but long enough to determine if the symptom is present.
If you can do this with the belt removed then this eliminates any accessory drive as the source of the problem.
If the symptom is still present this suggests it is a fueling problem, which could be an intake air leak.
Would be interesting to observe the fuel trims before, during, and after the symptom appears to see if these are showing any indication of fueling trouble.
