High Idle

[landcruiser]

I have a 2002 996tt. It started to idle high and just recently gave me a check engine light. I cleaned the MAF and installed a new K&N air filter, and the problem still persists. When I turn the A/C on it idles just fine. I piced up a OBD pocketscan and it gave me the following codes P0507 and a "Pending" code of P1133. Guess I need to make a trip to Porsche next week to diagnose.. Does anyone have any ideas?

Thanks

[Loren]

:welcome:

P0507 32 Idle air control at stop - above limit

Possible fault cause

- Throttle is jammed

- Leaks in intake air system

P1133 358 Oxygen Sensing Adaptation, Lower Load Range, Bank 2 - Below Limit

Possible fault cause

- Incorrect signal from MAF sensor

- Fuel pressure too high

- Fuel injector leaking

I would start by cleaning the throttle body with carburetor or fuel injector cleaner (spray). Also, clean the MAF with MAF cleaner (ONLY).

Re-assemble and check for any leaks and torn or worn hoses.

Then clear the codes and go for a test drive.

[Sunnyside]

Try carrying out a throttle valve adaptation. Disconnect the battery, leave for 10 minutes then reconnect. Switch on ignition to position 2 , don't start and touch anything at all for at least 10 seconds. Turn off the ignition remove key. Then start car as normal. That will take the throttle through all its movements. Hopefully if there is dirt or a sticking patch it will clean up.

Its worth a try before doing anything else.

:welcome: to the fold by the way. :thumbup:

Edited July 15, 2011 by Sunnyside

[Black996X50]

I have a 2003 996ttS with a similar issue. It's idling high, but I also have the smell of fuel at the rear. After a solid drive over the weekend, I would go so far as to call the smell 'strong enough not to drive without Rescue 51 on standby' :-P. Another RT thread cited the air connection coming down on the driver's side forward of the turbo. I checked that connection (not sure what that little thing is, but it is only on the driver side) as well as the other air connections I can see and all seem to be in good condition and connected. The only unconnected tube I have is for the little coolant overflow/drip drain to pavement. Another RT thread let me know that the fuel filter on '03 and later 996's is integrated into the fuel pump (can anyone confirm this is also the case with the TT?) The very helpful codes in this thread seem to point toward an injector. It's has high idle and a fuel smell at the rear with 57k miles - sounding "injectorish."

I should be able to start pulling it apart next week to get the final diagnosis I will try to post some photos.

Can anyone confirm, deny or provide further thoughts?

Thanks!

[EleCTriCT]

2001 996TT

Complaint: CEL on...

Code stored p0507 - noticed occasional high idle and the odd sputter on W.O.T. accell...

Diagnostic work flow....

piwis - fail... hardly any actual values shown on this model - durametric beat it with values hands down..

Check for vacuum leaks with smoke machine.... none, clean and re-adapt tbody (KOEO 60s)

Problem still persists. The throttle valves hardly fail and we all know the bosch MAF's are sh!t so I put one in.

the kg's per sec went up from 14-15 to 17-19 and the actual throttle opening percent went from 2.7 down to 1.7

All at operating temp at idle.

btw the car also reaches 200km in half the distance with a new maf :P

Hopefully this might help someone. Cheers

[jmrosen]

On 7/27/2011 at 5:20 PM, Black996X50 said:

I have a 2003 996ttS with a similar issue. It's idling high, but I also have the smell of fuel at the rear. After a solid drive over the weekend, I would go so far as to call the smell 'strong enough not to drive without Rescue 51 on standby' :-P. Another RT thread cited the air connection coming down on the driver's side forward of the turbo. I checked that connection (not sure what that little thing is, but it is only on the driver side) as well as the other air connections I can see and all seem to be in good condition and connected. The only unconnected tube I have is for the little coolant overflow/drip drain to pavement. Another RT thread let me know that the fuel filter on '03 and later 996's is integrated into the fuel pump (can anyone confirm this is also the case with the TT?) The very helpful codes in this thread seem to point toward an injector. It's has high idle and a fuel smell at the rear with 57k miles - sounding "injectorish."

I should be able to start pulling it apart next week to get the final diagnosis I will try to post some photos.

Can anyone confirm, deny or provide further thoughts?

Thanks!

Was this ultimately an injector issue? I have similar issue now myself. Although I did brand new injectors 5K miles ago (and all four fuel lines as a precaution (2004 996 Turbo with 31k miles at the time ) as I had heavy fuel vapors from rear engine bay after driving aggressively and there was absolutely no leaks nor could we determine anything but surmised a lazy/leaking injector into combustion chamber after key is turned off and the strong fuel smell it left behind. Along with colder new plugs (have an FVD tune, all else stock) and did new coolant tank age preventative and GT2 clutch and pressure plate kept duel fly and clutch assist, I prefer it.  Ran beautifully for past year, today high idle at 1000 / 1100 rpm then back down to 7500 normal and up again, along with return of fuel smell in garage! Dear lord. In exact same area in bay. Could this be another bad injector, coincidentally was not the injectors to begin with last year or did that do trick and now it’s something else, no CEL but old code for intermittent idle. Any help would be greatly appreciated. 

Edited January 8, 2023 by jmrosen