I've read numerous threads with the same problems my 00 clk430 is having but not a single definitive solution.*The car hesitates when attempting to accelerate.. not the sight delay people speak of but a good 5 second delay between "flooring" it and it gaining speed. For example, at 55 if I step on it to overtake it revs between 3 and 4 thousand rpm and seems to be dropping down a gear however I'm sitting there as the car lags and experience a rubberband effect... waiting there for acceleration that doesn't come.*This is a recent event, the car used to be very snappy. The car currently has 93k miles and I replaced the MAF last year with the suggested Bosch..which corrected a check engine light issue I had at that time.*HERE'S THE TWIST.. I've read numerous posts stating this could be a vacuum issue, a maf issue, spark plug wire, catalytic converter...even one guy with a detailed explanation of sand in his engine. However, when I disconnected the battery and reconnected it the car accelerated as it used to for a week or so before again returning to the hesitation / lag issue. Therefore, it must not be a physical issue i.e. disconnected spark plug wire or crack in a vacuum hose. Also, again, it isn't a slight delay in response and has nothing to do with the adaptive throttle response.. This is a long, delayed sputtering hesitation when stepping on the gas.*So... disconnecting and reconnecting the battery corrected it for a period of time until it started hesitating again...any ideas?

 

Hi,
Have you found a solution to the hesitation issue?

 

I have an impression that the fuel pump is causing the issue.