need help from experts PLEASE, i have a problem with a 230E mercedes 1983 type 124 . the engine doesnot run smoothly during low RPM , when you increase the rpm it performs smoothly no problems there, and it accelerates smoothly aswell . i tried adjusting the air fuel mixture ,now the exhaust fumes smells rich of fuel, makes your eyes burn.
any suggestions or help would be appreciated cheers
Hi, was it working fine before? When was the last service and what was changed?
Did you adjust the idle speed control as well?
Regards, ws
Ok, first make sure it is not something simple, like the OVP relay/fuse.
Fortunately, it's mostly mechanical. The electronics regulate idle and cold start.
Idle should be about 800. I believe. You should not have touched the fuel/air mix adjustment, it is for CO emissions.
This is for the older K and D models, with some comments on the KE model:
Google around, I believe there is more information on this.
Regards, WS
A small vacuum leak can cause partial misfires and less than smooth idle which disappear as the motor's speed increases. That's because the small vacuum leak becomes an insignificant factor in the motor's air / fuel volume at, say, 1,500+ rpms vs. a 600 rpm idle.
Suggest you look for and listen for a vacuum leak's hissing - could be a cracked vacuum hose or leak at an intake manifold gasket. Suspected sites can be checked by CAREFUL application of a combustible like propane or fuel to the site. If the motor then idles smoothly (from the added fuel) the leak is confirmed.
In any event, vacuum leak or not, the motor's air fuel ratio ought to be restored to specifications for fuel economy and environmental reasons.
I have had occasional success locating a small vacuum leak by spraying a short duration, fine mist of starter fluid near suspected places around the intake while the car is missing. If there is a vacuum leak, the idle will increase, thus making the leak easier to locate.
Obligatory "diluting the gene pool" *Warning*:
The above is a report of experience NOT advice! Starter fluid is flammable read the label. Do not attempt on a hot engine. Do not use excessive amounts. Adequate ventilation is necessary. Don't drink it. Have a means for extinguishing a fire handy. If you are not flame proof don't do it at all! Most of all, don't be stupid.
Now I know why the drug company's disclaimers are so annoying.
Use carburator cleaner instead.. and you will feel the stumbling instead.
A very good suggestion. Thank you.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required