My nephew has a '99 E55 he bought new. It has always had a 2 second delay after flooring the throttle before it begins to accelerate. This occurs from a standstill or from any speed.
You floor the throttle and it just kinda eases out for 2 seconds, then it really takes off and screams. We thought it was just a slow tranny shift, but it does it from a dead stop or when you maunally shift down at cruise and then floor it. It's kinda embarassing to get nailed by a Honda at a red light in a car like this. The dealer says it's normal "they all do it". We called one of the tuners (Renntech, i think) and they said sure they could make it fly, just bring it in and they would fix it all up for a few thousand $$$ with their secret tricks.

I just can't believe a car like this would be built to perform this badly intentionally. Maybe some kinda drivetrain-saving function or something. We thought it might be in "winter mode" or the kickdown switch under the pedal was not engaging, but that doesn't seem to be the problem. It doesn't seem to be a bog or engine miss, it's just a very repeatable lag like the computer is holding it back for 2 seconds. Other than that it runs like a dream, and is REALLY fast once it gets going.

Any inputs on what is happening and how to remedy it? Could an aftermarket chip be a cure? Can anyone verify that "they all do it"?

S-Class Guru

Dr. D, thanks a bunch for the reply. Now at least we can relax knowing it ain't broke. We'll see if the nephew can modify his Honda killing to anticipate a bit more, or just get his jollies by coming from behind and blowing their doors off as he goes by.
Hmmmm, maybe the Klemmenn supercharger would provide even more "door blowing" fun!!!!!

S-Class Guru

Great story!

By the way, what kind of car do you own?


And Dr.Diesel,
I'm out here in Issaquah, I didn't realize there was another member in the area. What shop do you work at? I've been looking for a good place to take my car for some servicing and a few problem checks.

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-Kevin

I had this _same_ thing with my 98 C43 AMG. I got two things for ya.

Step 1) Have your friendly neighborhood MB service center set your "ignition" to "RON93" via their Mercedes Star Diagnosis Computer. That's equal to saying to the engine "I'll be using US Octane 91 fuel", and is retarding the ignition. [you may have to grease a palm].

!!!=does not affect emissions=!!! If they say it does, they don't know what they're talking about. If they won't do it, they're just being pains in the arses -- another service center will. [as a matter of fact, since I've done it, I never get that "rotten egg" sulfur smell from my exhaust during hard driving anymore!]

This made a =dramatic= difference in peddle response for me. The car jumps as soon as I touch the throttle.

2) This may be hard to believe, but ... Don't floor the car off the line! Go to 1/2 to 2/3 throttle off the line quickly, then go to full throttle after say 3000 RPM (1 second).

...betch'ya that does it.

Does this happen if you select the 1st gear transmission lever and then floor it?

Regardless, something does not seem right, maybe a 1/4 to 1/2 delay but not 2 seconds.

I live in Sweden and I have a 99 E55. Something is wrong with your car. Do you mean that your wheels doesn't spin when you floor it from zero with esp off? When I do that my tires spin like hell! But when I bought the car it didn't. Read this:

Mass Airflow Sensor Miracle

I bought the car after reading all the reviews in the magazines, which at the time liked to show the car burning rubber from takeoffs. My car never did that and I have always been disappointed in the power at low speeds and the transmission which hesitated on down shifts. I always complained to the dealer, but nothing really changed. I thought MB should study a Cadillac Northstar engine and GM transmission.

Then I read in another forum last Sept that several others had the same problem which was corrected by changing the mass air sensor. I had to take my car in last week for a Service A at 38,000 miles. I told the service writer about my complaints and begged him to look at the mass air sensor, and even told him that the forum messages said problems with the sensor would not show up on a regular diagnostic check. When I picked up my car I was told the sensor had been replaced. I left the dealership and entered I 95. I goosed the accelerator and to my surprise was thrown back into my seat by the power. It was almost scary. It feels like there is another 100hp! The car now loves to provide instant downshifts. The ESP turnoff button now works and the back tires spin all the time.

These things are very cool. I don't remember ever reading about the mass air sensor or the 'ron93'

Does my 1994 E420 have either of these things?

I thought the ignition would be set for 91 octane since that's what we're supposed to use.

I'm going to read more in the archives about the Mass Air Sensor.

A question I have....different topic, so I might stasrt a new one, is:

If my coolant temp sensor is reading cold (60 degrees C), is the motor always running rich, waiting for the motor to heat up? I was told there are 2 coolant temp sensors on the M119 motor. If it is, how would this affect the performance? It seems a bit sluggish.

Thanks,

Craig

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1994 E420, Pearl Black/Black. 2.82 rear diff., AMG front spoiler, painted lower half. SOLD

1972 & 1974 BMW 2002tii's.

When i was working at the dealer my friend and I decided to play around with his 202( i think it was a 99 ), it had the 112 motor in it and we did the Ron93 programing and he said that when the car came to operating temp that it was much faster, but he noticed in the morning it would crank longer and run rougher than before until it got up to temp. Idk i always wanted to play around with the laptops and program the american spec cars to germany spec ie no speed limiter but my shop forman told me when i buy a benz i can do whatever i want but dont do it to other ppls carslol.

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1982 300D Turbo (Mom's)
1993 BMW 525I (Dad's)
2001 Vw Golf (Brothers)
2002 Nissan Ser SpecV (Im the Black sheep lol)

Mercedes was supposed to have fixed the tranny on the '99 models but I don't feel they did a good enough job. I know Mercedes fixed the 2000 and later models and they do not have the lag. I can just about guarantee it is not the MAF. I replaced the MAF in my car and it ran much better but the tranny still lagged on kick-down. A bad MAF will cause very sluggish acceleration and is really evident around the mid to upper rpm range.

you can ask the dealer to check the clutch pack clearences with the star diagnosis tool. I forget the specs havent been workin on em for about 8 months. Just go to the dealer and tell them that you feel the trans is slipping and they will (should) check the adaptations on the trans.

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1982 300D Turbo (Mom's)
1993 BMW 525I (Dad's)
2001 Vw Golf (Brothers)
2002 Nissan Ser SpecV (Im the Black sheep lol)

Our attempts to version code peoples fuel mixture on AMG cars
has always yielded negative results in terms of cold start problems and poor idle quality with no noted improvement in throttle response.

Replacing air mass sensors for "suspected" throttle response issues is also now tougher. MB has a new "TEST
and PROCESSING center" for all parts replaced under warranty.
If we replace it, they will bench test it. If it is not completely
faulty for them (check engine lamp on), they will not pay us for
the warranty repair, we loose the $ for the part and labor.

As the fuel inj systems and transmission control systems got better and better in 2000 and 2002, this problem seemed to
be getting smaller and smaller but,
One of the biggest things we have seen with V-8, V-12, and AMG
cars is the ESP is so sensitve to wheel spin. It has been proven that by the first rotation of the drive wheel (burn out) the ESP
system begins to interupt with throttle and ignition retarding.
The system will completely back off the throttle and won't even
flash the traction triangle in some cases.
This usually occurs on hard throttle launches (stop light drag)
and feels like the cars has no go-power. 1-2 seconds later, the
ESP system feels wheel spin is under control and turn the power back on.
Turning the ESP off will show this in most cases with spinning tires
instead of delayed throttle next time you "stand on it."

Good luck.
DR.D

You're like a dream come true! Where do you work? [say long island ... say long island ...] You can do =all= the experimentaion you want to my car - 98 C43 AMG.

I concur. I should have also stated pretty much every sensor on my car was replaced. I believe the two stage manifold was also not working properly, and had been worked on.

Is the car's transmission in W or S. If it is in W, itll give you a second gear start.

Sorry but i dont work at the dealer ne more plus its in new jersey lol . I had to quit because of college. Maybe after college ill get a job at montvale though and can play around as much as i want.

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1982 300D Turbo (Mom's)
1993 BMW 525I (Dad's)
2001 Vw Golf (Brothers)
2002 Nissan Ser SpecV (Im the Black sheep lol)