Mercedes w201 190e 1993 1.8 petrol

[nbilkhu]

Hi, I am new to this group and my first post, so appreciate any help you can provide on my issue.

I am thevproud owner of a Mercedes w201 190e 1993 1.8 Petrol the car has done 90k miles with full service history and in immaculate condition.

The car has recently developed a small issue when idling (stationary) the revs drop from just under 1k to about 500 for a split second and then goes back to normal. This happens evey 2-3 minutes, NOT when driving, just stationary. Today I took the car for a long run and issue got worse. I'm not sure of the correct terminology to describe the rev drops "slight juddering" or "hunting".

The issue seems to be more frequent when the engine is warm.

Distributor cap, leads, rotar arm, sparks are all brand new.

Any help you can provide would be appreciated.

 

[mattkh]

Distributor cap, leads, rotar arm, sparks are all brand new.
Any help you can provide would be appreciated.

You have not mentioned the idle stabilisation valve.

 

[DREAMER NO2]

I would start with the electrics, plugs , distributor cap, ht leads and rotor . Thats if you dont know just how long those have been in there . Looks a peach of a car, ,and i love the colour ,, Not to sure if your engine will have the idle air control valve . But if it has i would remove that first and clean it out with carb cleaner . Check all fuses in the fuse box . Look for split vacuum hoses and any splits in the rubber connectors .Looking at that engine i would say there is very little wrong with it .

 

[horatio]

Nice car! I would have a watch of mercedessource videos on the k-jet systems

Mercedes-190.co.uk forum is great.

Is the fuel filter prehistoric? Has it been run on E10?

 

[DREAMER NO2]

Yes by all means watch the video - but important that you dont play around with it . .Just look for vacuum leak and such . 80% of problems come from the electrical side .

 

[horatio]

Yes by all means watch the video - but important that you dont play around with it . .Just look for vacuum leak and such . 80% of problems come from the electrical side .

I wouldn’t mess with settings but understanding how the system works is a must for diagnosis because you can’t just plug in a scan tool and you really don’t want to fire up the parts cannon with prices now. Unless you find a specialist most mechanics won’t have a clue.

There are some really good ownership tips in those videos - some really basic like lubricating throttle linkages.