I just purchased a 97 E420 from my brother. He always had it serviced at the dealer. He also had it tuned-up as part of the deal. I test drove this car several years ago when he first purchased it. As I can remember flooring the accelerator pedal on the expressway and feeling that burst of G-Force acceleration pushing me back into the seat, just like you would if you were in an aircraft. I was testing it again on the expressway since it was recently tuned-up, but that burst of power was not there. I'm thinking that the dealer did not do a good job on fine tuning this car. Am I missing something? Or did they do a lousy job? Can someone give some advice on repairing this problem?

it sounds like the problem lies between the accelerator and steering wheel (ie you)

It doesn't sound as though you're experiencing any mechanical or electronic troubles, just that you wish (or thought) that the car was faster than it is. Are you hitting the kickdown switch to drop the tranny to lower gears?

Please check out link regarding the power of this car. Here's a quote from "New Car Test Drive" on this vehicle. My post is not a bad post, it's a fact. Please do your homework.

"After its initial tip-in, the E420 has the throttle response of an aircraft carrier catapult. Pushing the pedal to the softly carpeted floor returns a thrilling explosion of acceleration, pushing you back into the seat as the car builds velocity. The cabin fills with the engine's refined snarl and the tachometer's needle climbs toward the redline."

I was not exaggerating about the burst of acceleration. It does literally thrust your head back without shifting gear. I did experience this serveral years ago. The car still has good power, but the burst was not there that it had.

Link for thoses that would like to read this write up:
http://www.nctd.com/review-drive.cfm?Vehicle=1997_Mercedes-Benz_E420&ReviewID=336

There's not really any "fine tuning" that can be performed on this car. The engine control module handles ignition timing, injection duration, etc. Other than gapping the spark plugs correctly and insuring the maintenance items are addressed, there aren't any adjustments necessary to maintain performance. Timing chain stretch, carbon build-up, and minor compression loss can cause performance to decline over time. Fuel quality can also contribute ( especially when fuel prices are high ). I would try some injector cleaner first. Good luck