So, I have read numerous forums on my issue and have done some work already and am drawing a blank now. I own a 2002 C240 with 117K miles and I live in Nebraska and recently have been having multiple misfire issues (on 4,5,6 cylinders). Here is the work I have already done:
Replaced the spark plugs
Tested all wires with an Ohm reader (all good)
Replaced all coils
Cleaned all Fuel injectors
Replaced one of the Breather tubes (i broke it when removing to clean the injectors)
Tested the fuel pressure: stayed around 50 PSI when running only dropped a little after doing the leak down test for 10 minutes.

So, I don't feel I have a pump issue, but I am still getting the same error codes and can't drive the car more than a block without it basically shutting down.

I feel like it is more of a computer issue, but I don't know how to check that. Any help would be greatly appreciated.

 

I have also now unplugged the MAF sensor and was able to turn on the car and drive it around. I still misfired on 4,5, and 6 but I didn't even think I could drive it with that unplugged. Is that my issue? Need a car soon so help is urgent.

 

So, I have read numerous forums on my issue and have done some work already and am drawing a blank now. I own a 2002 C240 with 117K miles and I live in Nebraska and recently have been having multiple misfire issues (on 4,5,6 cylinders). Here is the work I have already done:
Replaced the spark plugs
Tested all wires with an Ohm reader (all good)
Replaced all coils
Cleaned all Fuel injectors
Replaced one of the Breather tubes (i broke it when removing to clean the injectors)
Tested the fuel pressure: stayed around 50 PSI when running only dropped a little after doing the leak down test for 10 minutes.

So, I don't feel I have a pump issue, but I am still getting the same error codes and can't drive the car more than a block without it basically shutting down.

I feel like it is more of a computer issue, but I don't know how to check that. Any help would be greatly appreciated.

 

I have also now unplugged the MAF sensor and was able to turn on the car and drive it around. I still misfired on 4,5, and 6 but I didn't even think I could drive it with that unplugged. Is that my issue? Need a car soon so help is urgent.

 

moved to W203 forum...

 

ok guys, I joined this forum because I saw a lot a quick responses and I'm not feeling the love. I have now replaced the MAF sensor assembly and that helped a lot, but did 100% solve the issue. Before, I could only drive a half mile and get up to 25 mph before the misfired happened. Now, as long as I don't get over 2500 rpm, there are no misfires and got up to 60 mph. So, as long as I only stop on a down hill and don't care about accelerating fast, then I'll be fine. But let's just say I would rather just drive normally. What else can I check or do to make that happen?

 

I almost think it has to be something computer wise. If the car misfires, I can turn off the car and turn it back on and then it's fine again. Please tell me there is a simple fuse or something I can exchange to solve my problems.

 

mine was plug wires and over 100k is due for them; try swap wires between different cylinders and see if it follows

 

I tested all the wires and they were all fine (see original post). It doesn't matter anymore. I sold the piece of junk and suggest everyone on this forum do the same thing. These cars are poorly made and aren't worth the scrap metal that made them.