babason

Hi everyone. I have a c class wdb20208, which has had an engine swap the engine was running reasonably well on the donor vehicle. the only thing that was removed and replaced was the engine everthing else, is original.

on starting engine will rev up and down and the throttle/ accelerator makes no difference it wont even open the throttle flap.

I have reset the adaptations and tried to reset the throttle housing. the diagnosis tool come up with this message. Programming conditions not met see diagnosis manual engine vol 4 index 9.1-6 Conditions for programming.

I have not got access to this diagnosis manual and would appreciate if anyone could tell me what the programming conditions should be.

I have tried replacing the throttle housing same prob
New air mass same prob
checked all fuses.
fuel pressure ok.

actual value for ctp (closed throttle position) is no

any help whatsoever will be appreciated.

Finally Does anyone know where I can buy the MB diagnosis manuals that are not on wis ?????

benz-tech

a vacuum leak can cause this problem. check all of the breather hoses at the valve covers and throttle body area for cracks, splits or misalignment. although less likely, a stuck egr valve can cause the same.
what you don't state is what year and vehicle you have (not sure what a
wdb20208 is and since MB did not make a w202 in '08 your description doesn't help), and what engine you swapped in and took out. that info will help.
to perform a basic throttle re-set, turn the key on but don't start. wait about 1+ minute be sure. you may hear the throttle plate buzz or click. after that it has re-learned the stop.

babason

Thanks for taking the time, to reply

Chasisis no = wdb2020802f971083 C 200 year 2000 petrol ESTATE. ME injection system. vehicle was running fine untill I touched it

donor vehicle c200 saloon year 1997/98
hfm injection system.

all I removed from donor vehicle was engine.(engine was swapped due to very low mileage)

Everything else gear box.flywheel and crankshaft sensor. and complete injection system is original.

I have also dropped the exhaust incase cat blocked.

I found the correct diagnosis manual. all the programming conditions are right, and then it tells me to do exactly what you recommended, only it then tells me to switch off ignition. which I have done this morning. no joy.

when i try to boot strap the engine control unit, it still wont let the throttle valve reset.

Iam begining to think that the fault is with the throttle potentiometer,B37. I have had a quick look at the wiring diagram because I dont seem to be getting any lives to it but all wires to b37 come from the control unit direct.

do you know if the potentiometer b37 is faulty, snagged wire, lost earth etc etc this will cause the thrttle valve not to reset ???

I have been very busy and havent checked all this because i wanted to make sure the programming conditions were right b4 i dive in and probably drown.

any further thoughts would be appreciated.


thanks once again.

benz-tech

you could watch the throttle valve reset itself to be sure. it will buzz or click. if it is not going through this process, you may have a hard fault. i would doubt a failed component only because you had everything apart. HTH i else i can't think of anything else at the moment and even then i'd be guessing at this point

babason

yesss thanks

very very stupid me

b37 has cable. adjust cable and throttle housing hits ctp (closed throttle position) once seen by ecu, vehicle runs very nice. I could see from actual value that throttle valve wasnt at ctp but couldnt understand why. obvious NOW


thanks for helping me think, appreciated