Car ran fine/ sudden loss of power

[c220 diehard]

Hello all - thanks for the good advice on this site. Having a problem with my 1995 c220. About two weeks ago I was driving and it cut out did not stall but ran like in limp mode - could not get over 40mph with no acceleration power. Now the car idles at about 500rpms in drive and when warm searches between 500 and 700rpms in park. Thinking it was a fuel issue I replaced the fuel filter, fuel pump and fuel pressure regulator which all looked original - but the problem persists.
The car has 101,000 miles on it the engine compartment wiring harness has been replaced, new MAF, plugs and new gas cap all within the year. Has anyone had a similar experience or direct me to what I should look at next - any advice would be greatly appreciated!!

[Sulaco]

bad coil? plug wires?

pull codes and look for a misfire code to identify which cylinder is losing fire.

then swap the coils around and after the problem comes back, check codes again to see if its a different cylinder with the misfire. then you will have your culprit.

[c220 diehard]

just pulled a spark plug which was all carboned up - it was a Bosch F8DC4 and the shop manual recommends F9DCO which do I go with?

[Sulaco]

you said it was a new plug but it still got covered in carbon? i'd suspect a bad coil or bad plug wire at this point.

try to stick with OEM. the F8DC4 is a very common and great plug. DO NOT put fancy pants platinum or other garbage in an older MB. you can get the correct plug online at autohausaz.com or partsgeek.com

Note: don't get the FR8DC4 or anything with an R in it, it has an extra resistor inside the plug. These cars have that resistor in the plug wire instead. You'd be increasing resistance x2 and thus causing it to work twice as hard to fire. Wear out a coil pretty quickly.

[c220 diehard]

Thanks for your help - much appreciated