I have a 2002 Mercedes c240 and have been having I think fuel problems on and off. I changed the fuel filter and still having the on and off problems. The car runs ruff and dying issues then the rpms jump and runs perfect especially going down the highway but I come to a red light it may die or run ruff then take off perfectly fine. But also sometimes it won't run at all and won't crank and I never know when it will run normal or not. I was thinking it may be trash in the tank because I've had it towed and as soon as I get it home it crank and run perfect as if the trash has moved around etc. Could it be the throttle body be dirty? Also there is a few hairline cracks in the air induction tubes feeding the air breather box (k & n) air filters could that be a problem. This is my only means of transportation and I'm disabled do I don't have alot of money to goto the dealer. Thanks in advance.

 

if you have a K&N sometimes the oil messes up the MAF and it needs to be cleaned. I would start with that since you have a K&N filter. Thats a common issue with oil filters messing with MAF on our cars. From there you can check your spark plugs to see if they're firing correctly still then work your way to the fuel system and the tank. If you think there's trash in the take empty the tank and take it apart.

 

"and wont crank" tells me that it may be the battery . How old is the battery?