Hello, I have a 2003 341 Midi-x and it started to lose power, like a plugged fuel filter. I changed the filter and it still would bog down if I did any heavy digging or 2 functions at the same time. I started poking around in the engine compartment and found one of the distribution valve O-rings was shot and leaking fuel. I replaced all 4 o-rings and put the injector lines back on. When I started the machine, the exhaust was black!! Like smoke you out of the yard black. I shut er down and did a little interneting. I read that I could find the problem by cracking the injector lines and when the problem stops, it would narrow down the cylinder that's having problems. I did this to find the last cylinder (of course) has the issue. When I crack the fuel line going to cylinder 4 the smoke stops, the high idle comes back to normal, but now I have a dead cylinder!! I replaced the injector for #4 with no improvement. Next I removed the lines again to see if the fuel coming from the other injector lines was comparable to what #4 was pushing. Somehow, #4 has around half the fuel as the others. I swapped the distribution valves between #4 and #1 to see if that was the problem and now #3 has no fuel flow. Also, now the fuel shut off switch will not kill the engine. I have to crack the injector lines to kill the engine. Please help!!! I'm starting to think that the injection pump is my problem, but I really don't want to spend another grand to find out that it wasn't the problem. Thanks!!