2005 Mercedes-Benz M-Class idling rough

after getting a new fuel pump and 2 new crank sensors and a new wire, car is idling rough. problem disappears while moving.

Would you post a few more details about your car… mileage, when this occured… before or after replacing the parts you listed. Why were those parts replaced and who did it. And the biggie… is the check engine light on? And if it is, what are the error codes?

OK. it’s a long story! I was idling the car in a snopark and it suddenly started shaking like a mother. Tried to move it but it freaked out (all the engine lights came on, sputtering along 2 or 3 feet at a time for maybe 50 yards) and died. It started one more time and repeated the performance, then wouldn’t start. Had to get it towed out of the mountains, naturally it was in the middle of nowhere so the car ends up at billy bob’s auto repair.
They say oh sure we can fix it, we are sending away for a fuel pump. 2 weeks go by, I keep calling them, finally they admit they also sent away for a crankshaft sensor. One more week goes by, finally they admit they cannot get the car started, and that se have to get the car towed 80 miles to a dealership because the computer is causing the problem.

The dealership says oh it’s the wire. They charge 500 bucks to fix said wire. They also charge for a new crankshaft sensor. (we had different people doing different parts of this correspondence so we didn’t catch that.) They offer to “diagnose” rough idle for $400, which we declined.

Picked the car up 2 days ago and it’s all shaky when it’s sitting still. Driving is fine, power is fine, drove it 200 miles home with no issues except it shakes while it’s sitting still.

My big concern is that she’s my mountain car, and I want to know if this foreshadows another 500$ mountain tow scenario, or if it’s just something that might happen with a new fuel pump. Or if maybe a hose is loose, as another forum post I read hinted.

Thanks a million!

Why did you balk at $400 diagnostic fee from a M-B dealer? That actually seems cheap from an M-B dealer. Expensive, complicated, German car (built in Alabama, I might add) that Billy Bob can’t fix but the dealer can.

So how many miles on this thing? Is the check engine light on? If you can’t answer these questions, I can’t offer any help from out here on the internet.