Engine Problem

Hi Norbert,

Thank you for the tip about backfiring. Actually I drive my car only from mechanic to the garage as I do not feel comfortable driving the car in this condition. Intry to set the speed to avoid the problem.

I did the exchange of the TPS and did not use any grease at all. The contacts are dry. The old unit was also in good condition but someone had suggested that worn contacts may cause such misfiring problems. Therfore I found this gentleman in NL through the net and ordered the piece.

I did not check the clearance of the engine valves and inspected the camshafts. I need yo consult my mechanic. Is there any literature I can read or ask SL club to provide from MB?As far as I can remeber the chain was replaced, several other parts were changed but I do not remember. I need to look it up.

I am also a member of the 107 SL club. I have access to the EPC. I can check If my engine type has the Hydrostössel.

There is a camshaft like part inside the ZV. that is creating the signals. Can it become loose after a period of time? Could it cause such problems If it does not spin properly?

I will do as Volker has advised.

All engine mechanics I have known work with the motor while idling and mechanically try to simulate load by manually adjusting throttle on the engine. This problem is audible during all these tests

Thanks again for all the advice.
I will keep you posted

MfG aus Istanbul
Juan

Hi Juan,
you find everything you need on top of this page "107 workshop manual".
jetronic.org/en/107sl-wsm/107sl-wsm-cont...7sl-ri-engm-m116m117
05-210 to 05-215
But a mechanic doesn't need this to inspect the camshafts for wear. My own car (Opel, no Mercedes) started backfiring when 5 of the 12 cams were almost gone. Had measured engine compression before inspecting the camshaft without great abnormalities.
The 'Hydrostößel' corrected the wear until the valves didn't open any more.

The engine had a decrease in performance (no more then 150 km/h) - but was still driveable, many hundreds of kilometres up to the time the same problems you described occured..

But check the ignition first... hope you have another problem than I had.

Regards
Norbert

rsadut wrote: Hi Norbert,
I am also a member of the 107 SL club. I have access to the EPC. I can check If my engine type has the Hydrostössel.
MfG aus Istanbul
Juan

Hallo Juan.

your car has no Hydrostößel. that only came 1975 with KA-Jetronic.

Hello.

I would also agree that it is a sparking problem, maybe with the rotor inside the zundverteilerkapp, as some cars were with limited engine revolutions. That rev limiter, is actuated by the centrifugal force of a smalll weight against a resort( small spring) in the rotor. With time, that device dont work very good. and is messing up ignition times.
As Volker sugested above, is unburned fuel in the exaust. If the engine, idles well, performs well, and is going ok untilll a certain revolution level...it means, that has gasoline, compression and spark. The only one of them that can vary is the spark /ignition advance. Maybe your advance is too high,you can check this on the foot of distributor.
Check also what spark plugs are installed in the engine. Too cold, or too hot. What colour are they?

There are also other things to check, but these are the first ones to look.

Thank you

Adi .

Hi Adi,
Welcome to the forum - you introduced a good new idea. Maybe you are right.

It's great others think about the same item with a different view and another background - I by myself didn't consider the rotor because I didn't have to do with these since - yes, 35 years.

Regards
Norbert

Hi,

a wrong working limiter in distribution finger normally means that you come to a certain rpm and then it will not accelerate further. But Adi is right that a loose rpm limiter could create strange effects. Easy to verify though: Use the finger without limiter as listed in appendix A for early M116 engines.