irokdastar

While driving at low speeds and RPM If i want to accelerate quickly i go to hit the pedal but i get a small increase. in power for 2 -3 seconds then the power kicks it .Mind you my foot the whole time is on the pedal. I have to take my foot off and press the gas again . If its in park or neutral it runs perfect but under load when i try to give it gas it falls . No dash lights or warning . What can be causing this?

Yidney

Is what you are describing clearly a new thing it has not done before? Because as you describe it that could describe exactly what I hate most about my car, but it has always done it and it's normal as far as I know. When cruising steady at say 35 mph, so that the revs have dropped to only 1,200 or so, then I punch it, it's as if the throttle (1) calls the post office; (2) negotiates the price of a stamp; (3) orders said stamp online; (4) mails a letter to the tranny and ECU; (5) tranny and ECU meet over lunch to decide whether to honor the request for more speed, and (6) I go faster. Starting from a stop or before the tranny shifts so the revs are still at at least 2,500 and it goes like crazy, but once shifted to the higher gears it seems like forever. Now, if I used a stopwatch, I'm sure it's not really a full 2-3 seconds, but it seems very long. It basically feels like turbo lag. Exactly like that.

Rudeney

This throttle hesitation is pretty typical of MBZ cars. There are some aftermarket fixes (SprintBooster or an ECU tune). Re-syncing the "drive by wire" throttle might some, too:

1. Make sure everything in the car is turned off and closed.
2. Turn the key to position 2 so all the dash lights are illuminated.
3. Press the accelerator fully to the floor, depressing the "kick-down" button.
4. Hold he pedal for 5 seconds and continue to hold it down.
5. Turn the ignition switch back one click to position 1.
6. Release the accelerator pedal, but leave the key in position 1.
7. Sit quietly and wait for about two minutes - do NOT open or turn anything on.
8. Listen for a "click" or "ping" noise form the dash.
9. Start the engine and drive the car for at least five minutes.

xsever

HAHAHAHAHAHA!

irokdastar

Lol Great description Yidney . Its been like that from when I got it but I always thought it was an issue Like cleaning the MAF or carbon buildup on the throttle plates . Thank you Rudeney I will try the reset . If I go the ECU tune Route . Whats the best tunner to get ?

Yidney

I've done the reset several times, although not in several years because I forget to. It definitely makes a noticeable difference, although it's hard to describe exactly what the difference is. Sort of feels like it holds a gear longer before shifting, which at least gives the impression of the car being quicker, even if it is not. However, I do not recall that it has any effect on the issue we are discussing here. I guess I'll do it again and see.

labguy

If I want to ensure a quick response, I usually manually downshift a gear or two before stepping on the throttle pedal. Otherwise, I get what you are getting - a huge delay.

Anker

Funny, I don't see this. Even in comfort mode, when I step on it it downshifts and off we go. This is my CLK 350.

I suspect that what is happening is that if you don't spiritedly all the time (lots of city driving), the ECU thinks you want old lady performance. The reset gets it to forget what it learned and start all over from a more spirited starting point.

Rudeney

The TCU is adaptive and will learn your driving habits, but the hesitation has always been an issue for me in all MBZ vehicles. Even in my SL, which ash the sport-tuned transmission, in sport mode, and definitely not driven gently, it will hesitate when I floor it while rolling.

As for ECU tunes, I've never had one so I can't make a recommendation. I think the least expensive solution is the Sprint Booster. I have no experience with it, but have heard a few good comments on the forums.

Amir_AMG

you have a clk500 I would recommend sprintbooster over an ECU tune. Tune wont give more than 10-15 HP which wont be noticeable and a lot of people bash on Sprintbooster, but when I had my CLS500 sprintbooster got rid of that "lag" immediately. I would spin tires if i left it on the red" race" mode...make sure you look into the newer one with a green and red button so you can switch

Rudeney

Te thing I like about Sprint Booster is that it does what it advertises: it remaps drive-by-wire accelerators to provide better response. Honestly, I think that's about all some of those so-called ECU tunes do for normally-aspirated engines, yet they make claims of big HP gains, hoping that drivers will just do a "butt dyno" instead of a real test.

Reanimation

Ha ha ha ha

irokdastar

I have seen a couple of people complain about the tune that after its done they had engine issues . I will do some maintenance like cleaning the MAF . Last time I changed the spark plug the driver side bank for some reason had all wet spark plugs . I don't have an engine issues or oil loss . Can it be coils?

Yidney

Can what be coils? Basically we are saying that what you are experiencing is normal. It's just the way the car is.

Bill51sdr

I have always been under the impression that this throttle lag is related to the traction control system, the idea being it is not allowing the rear wheels to spin under the torque hit from full throttle. I find it less intrusive when I turn off the DSC but it is still there. I have been considering driving the car in "Dyno Mode" to see if it persists.

I find this issue dangerous at times. I have been in situations where I needed full throttle *now* and instead got the *pause*. I have also found that more gradually tipping in the pedal will get you decent acceleration without the delay as this only seems to occur when you mash the pedal.

I have only really experienced this issue with my 550. My wife had a 2006 CLK 350 and I very rarely experienced the "pause" in that car.

Rudeney

It's not ESP; it's the electronic throttle, and it's not just MBZ - many cars with electronic throttle controls do then hence the popularity of the Sprint Booster. My CLK550 and SL550 will both spin the wheels when hammered, just a second or two after hammering the throttle.