hello, my 89 300ce has a surging idle on the low side it tends to stall while turning wheel or adding a load on engine,then restart is a bit hard,could this be from a vacum leak or possibly a failing fuel pump??

fuel pump : not likely . the common problem is ; either a failing fuel pump relay or/and the over voltage relay. they can re re-soldered.
Its best to replace both these ageing components and all the fuses in the box.
if not replaced, the fuel filter and thoroughly clean the idle control valve .
mak
300se

i will replace the fuel filter,do you know if its inline and where its located?,also where is the idle control valve located,i would assume its under the air box on the side of the throttle body? im sure its full of carbon,if its anything like an idle air control valve.

103
the fuel filter is at the back adjacent to the fuel pump. right next to it is the accumulator best replaced now along with the filter .
the idle control valve is under the air cleaner box. it has two rubber pipes attached to it and a two pin electrical connector, remove and clean.
the air intake plate should be spotlessly clean as should the inside bore and the butterfly at the bottom end ,carb cleaner will do the job. all this effects the idling speed .
hope this will help
mak

103
the fuel filter is at the back adjacent to the fuel pump. right next to it is the accumulator best replaced now along with the filter .
the idle control valve is under the air cleaner box. it has two rubber pipes attached to it and a two pin electrical connector, remove and clean.
the air intake plate should be spotlessly clean as should the inside bore and the butterfly at the bottom end ,carb cleaner will do the job. all this effects the idling speed .
hope this will help
mak

thanks i will check it all out,and clean the idle air valve

so does this mean the fuel pump on an 89 300ce is in line and not in the tank?

Correct.

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

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