Lately my 1988 190E 2.3 has been stalling when I come to a stop or slowing to turn a corner. Oxygen sensor light comes on prior to stall at times. In past weeks I have changed Oxygen sensor, plugs, cap & rotor and Idle control valve. Yet O2 light comes on after driving a few miles and goes off and on intermittenly. At idle RPM flucuates from 600- 1100. Seems like a slight hesistation when hitting accellerator. Also put in trans (used) two months ago and has some hard shifting. I would appreciate any help or ideas to fix. I'm open to all suggestions. Thanks for any help!!

For starters, I would check around for any possible vac leaks..

Thanks Arthur...I checked for vacuum leaks by spraying around injectors..etc no change in RPMs. The strange thing is that O2 light comes on when driving and car stalls at stop then it recycles off on restart. O2 sensor is new only two weeks old. Is there anything that would affect the O2 system? One mechanic suggested new ECU. Are there any diagnostic procedures I could try?

HI

Make sure to check this part out because this solved my stalling problems.

http://www.***************/search/product.aspx?sid=cmvjdia3fhz55155dm2u4l55&makeid=800016@Mercedes&modelid=1192654@190E&year=1988&cid=screen@screen&gid=6200@Fuel%20Filter

-Fuel filter in tank screen

This requires you to remove your fuel tank but it could be the source of problems.

A dirty or clogged fuel filter in your gas tanks will cause air in the system and hence cause stalling.

I checked all the electronics related to the fuel system and everything thing checked out so i looked there and it was clogged and dirty. I replaced it and the car runs great agian.

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

My 2.3 16 valve is doing the exact same thing, and we can not figure out what is causing this, so perhaps i should check out the fuel filter as well......mine only stalled out once, but it hesitates when accelerating and sometimes feels like its going to stall out when coming to a stop.....any other possibilities that it could be??

It is a common problem on mercerdes for the fuel filer screen in the gas tank to clog up. On diesels ive see it hasnt made the car stall or anything but on gas ones it can cause your car to stop working completely.

Also listen for air bubbles by the fuel pumps. Thats how I isolated the problem.

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)