M35 Stalling Issue

[bechopps]

Ihave a m35 rs4 with vq25det.

Recently when idling at lights and etc , the car will go from a normal idle speed and with out any warning drop in revs. It will then stall or almost stall. If it doesnt stall it will just barely idle for ten seconds or so then return to normal. A jab of the excelerator brings it back too. It doesnt make a difference day or night and whether in gear or not. While it is idling slow ( rough) , i have notice black sooty smoke from the exhaust. I might be wrong but it also feels like there is a lack of boost when encouraged to do so,

Can people please tell me what i should be looking for to get this issue sorted, or give advice of any sort.

cheers!

[scotty nm35]

I would try cleaning the throttle plate, they gum up quite badly. You would possibly need to do an idle learn afterward.

Its unusual that it does it sporadically, perhaps you should clean the AFM sensor too and check the plug for it is in tight. Are you running a paper air filter or a K+N?

[ChrisB]

I had the same problem with a VW Golf once. It would stall sporadically at idle. Everyone said it was the air flow meter so at great expense, I changed it.

It made no difference.

Turned it was the throttle body was really dirty with gum and coke.

Removed the throttle body, cleaned it and the intake with carburetor cleaner. Problem solved, never ran better.

[andy65b]

The newer cars with Electronic throttle bodies do not have an Idle bypass... so when oil residue builds up around the butterfly the throttle is almost 100% closed when you release the throttle thus almost stalling and air is sucked past the butterfly to keep it running.

When you clean the throttle body be careful to not push the throttle body open as it can damage the mechanism.

When you reset the Idle learn if the idle does not set at 650 rpm +- 100rpm the idle will not learn the new setting.

[bechopps]

thanks each of you for your advice. I will clean the throttle body when i can and keep you informed .

cheers again!

[bechopps]

thanks each of you for your advice. I will clean the throttle body when i can and keep you informed .

cheers again!