Abrupt initial take-up of drive

[Gastro]

My 1992 (late)W124 E280 has just cracked 110k and continues to delight with the exception of one aspect of its behaviour. Unlike all other MB's I've driven of this type, the throttle is very sensitive when opened from rest. Consequently the gearbox grabs first and assumes full power acceleration is being called for every time I'm moving away from a standstill. Consequently, manoeuvreing in confined spaces such as multi storey carparks results in a series of 'lunges' in both directions entirely beyond my control, and patently not good for the car in the long term.
I've suspected the setting of the control pressure cable and examined the Haynes manual for guidance on adjustment without success. Mine is equipped with the HFM injection system, and the manual begins by saying 'remove air filter housing'....but this is on the opposite side of the engine bay and is irrelevant to cable adjustment on my version. I've looked closely at the complex set of levers and cranks where throttle cable and control pressure cable converge and can't for the life of me see any pointers to align as the book suggests. In fact the arrangement on my car seems to differ from those shown in the book.
The control pressure cable has a red sheath. Should I loosen or tighten it to create more progression in the throttle from idle?
Perhaps you will have other ideas for me to try?
I'm a qualified but now retired senior technical motor engineer with 46 years of experience but not on the MB product until I bought this car last August.
Many thanks.

 

[television]

What are the RPM when in drive.

Malcolm

 

[Gastro]

When warm it idles in neutral at precisely 750.On selecting either D or R the revs drop to 500. It creeps in either direction on level ground as it should, but the first 5mm of throttle pedal movement piles on the revs disproportionately. Making right turns at tee junctions is extremely dicey if it's at all greasy or frosty....! It just grabs first gear and launches.

 

[kth286]

Gastro

Does it act the same whether the gearbox slider is in postion S and E ?

Are you sure it starts in first gear and not in second gear, as mine always starts in second gear ?

Have you oiled ALL the throttle linkages which is a service item on this model.

The throttle on these models is traditionally heavy and there is a miniscule of free play at the initial position which then "catches" and can easily cause wheel spin on start off in damp conditions.

Mine has done !47,000 miles now and never been adjusted, but always kept well oiled and is still heavy, but controlled.

Regards

 

[Gastro]

Thanks for your response David. Your observations are very interesting. I haven't oiled the throttle mechanism but I will.
You question on the transmission selector switch is probably highly significant and an issue I'd overlooked since it doesn't appear to work or make any difference to what the transmission does. I keep it in the 'E' position.
I've noticed that there are several mentions of the switch on this forum which seem to indicate that it needs stripping and cleaning from time to time. Perhaps I'll do that when I've lubricated the throttle linkages.
By the way my car is spectacularly immaculate in the engine compartment having been an embassy vehicle on diplomatic plates until I acquired it, and therefore subject to the daily TLC of a chauffeur. Maybe all the lubricant on the throttle levers has been polished off....!

 

[tom7035]

This thread may help;
http://forums.mercedesclub.org.uk/showthread.php?t=12527&highlight=pointer