Fellow members, i am in dire need of help!
Here is a puzzle for you, the car (95 w140 s600l/600sel its with the older m120 engine) is experiencing the following symptoms, the engine sort of gets (for a lack of better word) clogged/flooded, loss of power, it smells very strong of gasoline if you stand behind the car, not all cylinders are firing. The issue does not appear all of a sudden but sort of gradually within an hour of driving power is getting less and less, and when driving the fuel consumption gauge is constantly at max. It does not look like it burns oil or not much at least, and when the issue appears and the engine is revved for some time it sort of cleans itself (or maybe it passes on its own) with white/bluish smoke and runs fine until the next episode after a couple of months depending on driving.
When the car is started cold there is no smoke, and also when the engine is not "clogged" there is again no smoke and runs very nice.
This happened on one of the longer trips and has been re-occurring ever since with shorter intervals.
Some background on what was done on the car - new spark plugs, new distributor caps, new oxygen sensors, the dreaded harness for MAF sensors was rebuilt up to the computer box, harness for injectors was purchased new and original.
A compression test of the engine was performed and showed good compression on all cylinders, also when performing star diagnosis normal live readings from engine were found and no apparent error, however when we did the diagnosis the car was ok (its hard to get it to the shop in that condition for a diagnosis now).
Self troubleshooting was performed while the problem was present on the spark plug cables and an interesting thing was found, when we unplug cables from passenger side engine is sensibly affected, however when we do it from driver side its hard to tell if engine is affected at all, that turned our attention to the left coil, we had a spare new cable for the coil and we tried it but it did not show any improvement, we will try with a new coil (then again a failed coil will probably be failed permanently and not intermittently for the car to run ok for a while) and will also try with different ignition module (the square module that cables connect to on top of each fender). Throttle bodies have not been inspected but are humming as supposed to.
It sounds maybe like the spark is not strong enough for the fuel to get burnt or that fuel management is not ok.
Have not inspected the catalytic converters yet as i dont really understand how to inspect them and if they can cause such havoc.
So many things have been addressed on this car, can someone shed some light or come with wit a brilliant logical idea as to what might be the problem its so frustrating to see my well preserved baby struggle like this! I fear to think if its something inside the engine yet i am hopeful since the symptoms are not constant (indicative of a ware of inside components) and are coming and going.
Fellow V12 owners and mechanics and members, can we solve this?
Here is a puzzle for you, the car (95 w140 s600l/600sel its with the older m120 engine) is experiencing the following symptoms, the engine sort of gets (for a lack of better word) clogged/flooded, loss of power, it smells very strong of gasoline if you stand behind the car, not all cylinders are firing. The issue does not appear all of a sudden but sort of gradually within an hour of driving power is getting less and less, and when driving the fuel consumption gauge is constantly at max. It does not look like it burns oil or not much at least, and when the issue appears and the engine is revved for some time it sort of cleans itself (or maybe it passes on its own) with white/bluish smoke and runs fine until the next episode after a couple of months depending on driving.
When the car is started cold there is no smoke, and also when the engine is not "clogged" there is again no smoke and runs very nice.
This happened on one of the longer trips and has been re-occurring ever since with shorter intervals.
Some background on what was done on the car - new spark plugs, new distributor caps, new oxygen sensors, the dreaded harness for MAF sensors was rebuilt up to the computer box, harness for injectors was purchased new and original.
A compression test of the engine was performed and showed good compression on all cylinders, also when performing star diagnosis normal live readings from engine were found and no apparent error, however when we did the diagnosis the car was ok (its hard to get it to the shop in that condition for a diagnosis now).
Self troubleshooting was performed while the problem was present on the spark plug cables and an interesting thing was found, when we unplug cables from passenger side engine is sensibly affected, however when we do it from driver side its hard to tell if engine is affected at all, that turned our attention to the left coil, we had a spare new cable for the coil and we tried it but it did not show any improvement, we will try with a new coil (then again a failed coil will probably be failed permanently and not intermittently for the car to run ok for a while) and will also try with different ignition module (the square module that cables connect to on top of each fender). Throttle bodies have not been inspected but are humming as supposed to.
It sounds maybe like the spark is not strong enough for the fuel to get burnt or that fuel management is not ok.
Have not inspected the catalytic converters yet as i dont really understand how to inspect them and if they can cause such havoc.
So many things have been addressed on this car, can someone shed some light or come with wit a brilliant logical idea as to what might be the problem its so frustrating to see my well preserved baby struggle like this! I fear to think if its something inside the engine yet i am hopeful since the symptoms are not constant (indicative of a ware of inside components) and are coming and going.
Fellow V12 owners and mechanics and members, can we solve this?
