engine stall or stuttering problem

[nyashawm]

hi all. am in the DR Congo and have a peculiar problem with my w124 220e 4-cyl 1993 model with a 111 engine. on cold start it runs very well and revs perfectly but as soon as it warms up then it stutters and just stalls. if you leave it to cool down 20-30min then all is well again until its hot again which is now all the time with our hot weather here. can now only drive at night. i have changed the 2-fuel pumps, filter and fuel-pump relay. any help please from this nightmare, have no MB garage here

 

[nyashawm]

now its worse, engine will run fine cold-start then 1-5 miles the stutter and stall begins. have noticed however if i can force the revs 2000k/higher i can go as long i dont stop or slow down

 

[kth286]

do you have any garages that can read the fault codes.

you will likely find the spark is not getting to one of the plugs due to breakdown of the connector attached to the ignition lead (often the plug end)

so the car is trying to run on 3 cylinders and fails.

 

[nyashawm]

do you have any garages that can read the fault codes.

you will likely find the spark is not getting to one of the plugs due to breakdown of the connector attached to the ignition lead (often the plug end)
unfortunately i dont access to garages who can read fault codes and the few i tried b4 just created more problems for me. funny thing is if i can keep the revs very high it rides like a charm, impossible though in city traffic.
where is the cat and throttle body and how do i test them?

 

[Gruffofcdff]

Hello and welcome to the forum. as kth mentioned above I would first check the spark plug connections.
When it is running and up to operating temp try removing or eliminating one cylinder at a rim by pulling of a lead to the plug.
The early M111 would not suffer from throttle body or oxygen sensor problem in my opinion.
Clean the plugs first. Then mess about with the lead/suppressor cap connections and then the coil(s).
The early M111 uses pms ignition and the fault may lie with the leads or coil pack.
Later m111 engine uses hfm with a twin coil system which makes it a little harder to diagnose without HHT diagnostics.

 

[nyashawm]

Problem solved
took out the two ignition coils, and lo n behold enough dirt on the HT cable connections to last 10 years. needless to say removed the cables , cleaned the coils' sockets with solvent, replaced the damaged HT cables albeit with used ones( eish new ones the only shop in town with 'em wants US$210).also profited in cleaning the crank position sensor. now car back to normal since Monday no stutter or stall.
thanks to everyone for your help
Now have a new problem however. decided to replace the fuel pump and now my fpr is burning-up , fuse blown tree-times now.checked all connections tight , so now??????have wired the pump direct to the battery in the mean time before my relay is totally fried.

 

[kth286]

hope you don't have a fire as a result of eliminating the fuse - your
life insurance good ?