jozsef61

and sometimes idle will fall (almost stall) when you come to a stop. Also on some hot starts it takes like upto about 5 sec cranking to start car. When cold starts up first crank.
Are these all related issues? I had an engine light come on, and pulled code 2, so i replaced 02 sensor, and since then no enigne light, however these other issues are still there.
thanks in advance

72Audi

My dad's car does this also.
Maybe once during every hour of driving.
No consistent pattern other than it seems to always occur during light acceleration at lower rpms.

Dealer unable to recreate the problem.
Not sure if they flashed the brain while it was in their but they had the car for several days and at least they did NOT charge my dad for the rental.

Logically I am thinking that the lame electronic accelerator pedal is the culprit but also wondering whether the crank sensor may be lame like it was on my mom's 2000 E320.

Just not sure yet. Hard to troubleshoot since this happens so infrequently.

BT
1972 Audi 100 LS

RogerJones

For the M104 engine with HFM-SFI (i.e. not CIS-E), the E-Class owner's bible (which I quoted on another thread today) suggests for "shakes, misses on acceleration, dies while idling":

* defective hot film air flow sensor.

And for "poor idling and poor warm-up characteristics:

* air leaks around injector seals
* malfunction of EGR system, air injection system or fuel injection system
* idle speed and CO value set too low
* faulty spark plug connectors
* wrong spark plug gap.

Kestas

Maybe a dirty throttle bore?

What year is your E320?

MediumKahuna

Vacuum leak or EGR valve

shdoug

I didn't know the idle speed and CO were adjustable. Does it say how to adjust this?

shdoug

According to the manual, when starting the engine hot, if it does not start in 4 seconds, "depress the accelerator and continue cranking until the engine is firing regularly." If it's very hot they want you to press the accelerator slowly before cranking.