Poor starting and erratic idling

Dunvale

Senior Member
Joined
Jul 21, 2009
Messages
49
Reaction score
0
Your Mercedes
01 ML 270cdi (w163), 94 E200 (w124)
Hi all,
The problems with my 1994 W124 E200 are coming hard and fast these past few months!
The latest is that she tends to be hard to start along with lumpy idling when hot.
Its a confusing one, here are the symptoms.
A few weeks ago It was very hard to start one morning. It was just turning over. Took me a few goes before it started and then it died when I put it into drive. Got it going eventually and it was fine. That was kind of a one off.
I find it will start ok in the morning now if I wait for the buzzing of the fuel pump to stop.
Idles fine when cold strangely enough. Its when it gets hot that the problems start.
1. When driving, its fine.
2. After regular driving on the motorway, it will idle erratically. By this I mean the engine will rev and then drop in revs rhythmically between 500-1000rpm. I think the phrase is hunting or surging? It could be just sitting there idling away and all of a sudden it will shoot up to 1200rpm.
3. If I leave my foot off the throttle and let it coast along in drive it will tend to lurch forward in rythm with the dodgy idling,so I look like a learner driver who can't find the right gear! This tends to be a problem with reverse because when I'm backing into a space she tends to rev up of her own accord so I have to be quick on the brake to avoid slamming into something!
4. Most annoying of all is when the engine is hot and if I turn it off its hard to start again. The longer its left to cool the easier it will start.

I'm not sure where to start on this one, Any ideas?
 

smackc4

New Registration
Joined
Oct 17, 2009
Messages
1
Reaction score
0
Sounds like an air leak in a vacuum line to me...
 

Alex Crow

Senior Member
Joined
Jul 9, 2009
Messages
10,677
Reaction score
47
Location
Super Suffolk
Your Mercedes
W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
assuming you have the 111 (16 valve, silver rocker cover) engine with pms engine management, i suggestyou have a problem with the throttle valve. cleaning around the butterfly with carburettor cleaner may help, but you may need a new one! it is also possible to have them repaired i believe.
 

You lost your key ? Or maybe you need a spare! Your vehicle imobilliser does not respond anymore? WE CAN FIX THEM ALL !! Mobile ! Save Time and Increase Profits With us !
Top Bottom