Engine starts and dies - stab the accelerator and all is ok - no codes

[TugaMerc]

Hi
Can anyone help point me in the right direction please? I have a 1999 C280 W202 with the V6 2.8 engine. Randomly the car starts and dies immediately. If I stab the accelerator it maintains idle and does not die. It does this irrespective of hot or cold engine. There are no fault codes.

Thanks!

[SD202]

how many miles ? has the fuel pump / filter ever been changed ?

[TugaMerc]

how many miles ? has the fuel pump / filter ever been changed ?
The car has 107k miles, the previous owner had it serviced 2 years ago and I believe he did plugs and filter. What is the recommended interval to change?

[RemoLexi]

Check the breather hoses under the throttle body.

As well as cleaning the throttle body.

[SD202]

Check the breather hoses under the throttle body.

As well as cleaning the throttle body.

did the v6 c280 have EGR valve ? i know on my I6 c280 i had this issue. The EGR tube on the left back side of the engine looked like .......well for lack of better description ....a clogged " tobacco water pipe" down stem. ROFL full of black thick resin like dirt /oil build up .

[RemoLexi]

Haha the 112 does had EGR valve but it ain't a 420 supportive one! ;)

[SD202]

Haha the 112 does had EGR valve but it ain't a 420 supportive one! ;)


ROFL !!! :p

[TugaMerc]

Any specific instructions on dismantle an clean of the throttle body?

[TugaMerc]

how many miles ? has the fuel pump / filter ever been changed ?
Are these one item or seperate but housed in the same location?

[TugaMerc]

did the v6 c280 have EGR valve ? i know on my I6 c280 i had this issue. The EGR tube on the left back side of the engine
looked like .......well for lack of better description ....a clogged " tobacco water pipe" down stem. ROFL full of black thick resin like dirt /oil build up .
Is the egr "cleanable"? Have done so on other cars but never had a Benz hence the question

[SD202]

Is the egr "cleanable"? Have done so on other cars but never had a Benz hence the question


Are these one item or seperate but housed in the same location?

they are separate items in the same location under a small belly pan in front of the rear right wheel well , Yes the EGR can be cleaned its a pain to get to the tube at least on M104. But it did help immensly once cleaned with cold starts and hard starts. My c280 would sometimes not start unless i punched the gas pedal to the floor while cranking it. Cleaned out the egr tube changed fuel filter and the problem seemed to go away, I sold that car and it had sat for almost 3 months prior to being sold when the buyer showed up to pick the car up. it started up first try, So hopefully its something simple like that for you ! and not something more serious like a fouled out injector etc.

[RemoLexi]

I hate to disagree, but I have yet to see a 112 motor act this way due to a EGR problem.

Sounds like a vacuum leak. How do your brakes feel? The booster hoses broke often, but you wouldn't have brake assist

[TugaMerc]

Brakes are great, no problem. This seems more like a problem setting idle at startup. It is random and happens whether the engine is hot or cold. To counteract I just give the accelerator a small stab and all is well. I'll start by changing the fuel filter, cleaning throttle body and checking the breather hoses. If that doesn't solve the problem I'll move on to other stuff. Is the fuel pump suggested before a possible culprit? Does Mercedes recommend its change? the car is a 99 vintage with 107k miles on the clock.

[SD202]

I hate to disagree, but I have yet to see a 112 motor act this way due to a EGR problem.

Sounds like a vacuum leak. How do your brakes feel? The booster hoses broke often, but you wouldn't have brake assist

I was merely guessing same when i made the diagnosis and replaced the parts :eek: , The c280 i owned was M104 and not 112 it had about 190,xxx miles when sold.


Brakes are great, no problem. This seems more like a problem setting idle at startup. It is random and happens whether the engine is hot or cold. To counteract I just give the accelerator a small stab and all is well. I'll start by changing the fuel filter, cleaning throttle body and checking the breather hoses. If that doesn't solve the problem I'll move on to other stuff. Is the fuel pump suggested before a possible culprit? Does Mercedes recommend its change? the car is a 99 vintage with 107k miles on the clock.


The fuel pump and filter were changed at 125,000 miles on my C43 and at 180,000 on my c280. The c43 i didnt own when the job was done but since its a dealer record im sure it didnt need to be done. When i changed them on my c280, The filter was deff in need of change. but the pump questionable. I only had failed turnovers on cold starts and never after the car had been warmed up. I think dealer recommends the fuel filter at 50,000 intervals, and the pump at 120k . but i could be wrong. maybe remo can chime in on this as i know he will know better than i do.