Problem with C-Class

[sharp]

I have a big problem with my Mercedes C220, it is a 1994 model & it is a japenese version...
when i drive slowly the car automatically shuts off in any case in gear or in neutral. The RPM goes up & down & suddenly the car shuts off.
I asked about the problem thru a local garage & he told me that the main computer has problem & he might be right because i have changed lot of things in that car.
I have changed the airflow sensor, the fuel pump, but still the problem was not solved.
now changing that computer is very costly....
did anyone face this kind of problem???

[Street_Dreamer]

I have a big problem with my Mercedes C220, it is a 1994 model & it is a japenese version...
when i drive slowly the car automatically shuts off in any case in gear or in neutral. The RPM goes up & down & suddenly the car shuts off.
I asked about the problem thru a local garage & he told me that the main computer has problem & he might be right because i have changed lot of things in that car.
I have changed the airflow sensor, the fuel pump, but still the problem was not solved.
now changing that computer is very costly....
did anyone face this kind of problem???

the CPU shouldn't be that costly. in my mums old ML, we got it refreshed, coz the engine wouldn't pick up any speed. I think its one of them things that sometimes happen with a cars age, rather than modifications, though i may be very wrong

[McReis]

I have a big problem with my Mercedes C220, it is a 1994 model & it is a japenese version...
when i drive slowly the car automatically shuts off in any case in gear or in neutral. The RPM goes up & down & suddenly the car shuts off.
I asked about the problem thru a local garage & he told me that the main computer has problem & he might be right because i have changed lot of things in that car.
I have changed the airflow sensor, the fuel pump, but still the problem was not solved.
now changing that computer is very costly....
did anyone face this kind of problem???

Hi Sharp, and welcome to UCP.

My father owns a 1994 C280 and he has had some problems with engine management too. At first everything was pointing to the main wiring so everything was changed. But the wiring failure and some bad interventions done, supposedly should have messed with the CPU and partially burn it. Since all CPU's are numbered and coded for a specific car, a new one had to be fitted. Yet the car kept misfiring a lot, specially on lower revs, though it never shut off. After almost everything was checked up or replaced at Mercedes official dealer, the problem was a little minimized but still there. It was an independant specialist who finally found that the main problem were the connections to the spark-plugs. Something Mercedes check-up systems and electricians never found. It runs sweetly now, and all the power is available at any revs.

So my advise is to be sure that all the simple things are ok, and that the electrical wiring is working properly from one end to the other, before going into the most expensive stuff.

Good luck with that, and welcome to UCP.

[adamfraser]

Pretty much the same thing happeed to my Mum's Vauxhall, and it was the Idle Control valve that was the problem. Worth checking it out.

[sharp]

I will check it out & thankx for suggestions but i want more of them coming also....
I have heard from my garage guy that all C class have this computer problem...it is a failed model of Benz...but i think it happend to the 90s model....dont know about others but E & S class is surely superior.