Cold Idle Problem

[aligurun@sanmar.com.tr]

Dear All,

A common problem with Porsches in Istanbul (an the dealer can not remedy it):

My 1998 C2 has an excellent engine, however, when the car is started cold (that means at least an overnight stop), the idle is very poor and the engine shakes, and exhaust is smelling fresh Gasoline.

If I burb the gas pedal, either stops or stalls.

Switching off the A/C even makes things worse...

Just after 30 seconds after start, everything gets perfectly fine.

No fault code on test computer, new air mass meter, all hoses are clean, throttle body is clean (the dealer has replaced all these units but no change), the air filter is new, spark plugs are new.

Dealer says I have to stop 98 Octan and try 95 octan fuel and advices that the problem is because of the additives in the fuel, (however, I am not convinced).

I know at least there are 6 other 996 having the same problem in Turkey...

I really need help (and local dealer also does), any contributions will be appreciated.

Best Regards,

Ali GURUN

:help:

[a9jlu]

i have a similar problem with my 2004 C4s, on a cold start, for the first minute, the engine idles a little rough (slight vibration)

but i only have this problem when i park it outside, when it's in a heated garage i have no problems.

[0586slb]

Engine Coolant Temperature (ECT) sender can sometimes go bad. This will not therefore control the fuel enrichment correctly during the warm-up phase. The temperature gauge will work correctly, as there are two separate senders in the one physical device that you need to change.

Engine will idle better with AC on, as the AC unit sends a signal to the DME when switched on to increase idle torque.