(Note, I called the problem a misfire because that is what I think it is, but my assumption may not be correct). Hello, I am experiencing a problem periodically with my Deere 120C (2003 model). The issue is that sometimes (now, with increasing frequency) when the engine is at idle or under very low loads the motor doesn't run smoothly. I can feel that the engine is running roughly and there is an audible difference in how it is running (I think of it as "chugity chugity chugity" as opposed to a normal "whirrr" sound). When I put the motor under load (digging or moving, etc) the engine runs as normal. As soon as I stop digging for a moment it will revert to the rough feeling/sound. I changed the air filters, oil, oil filters and fuel filters about 50 hours ago or so. I checked out the engine the first time this happened and everything seemed fine. I am not sure if it is coincidence or not, but it seems to happen more often when I am facing up hill on a slope. This has lead me to think that maybe there is some contamination in the fuel or something that is getting mixed up and effecting the performance of the engine. Anyone have any ideas on what the issue may be or have any thoughts on how to diagnose? Thanks! Chris
My dump truck did the same thing about a week ago,, (3208 cat). It would miss at idle and low rpm, even going slow with no load. The minute I loaded it and made it really pull it would level out. It was an injector bad, I changed the injector and its been doing good. Good luck
Do you have any suggestions on how to identify which injector is misbehaving? It would seem that I'd need to buy a new injector and then begin the process of replacing one at a time until the problem goes away? Thanks, Chris
Shoot the exhaust manifolds with a temp gun as close as you can in the same spot on each one, keeping in mind the outer two will be slightly cooler than the middle two but should be within 20-30 degrees I feel like. Whatever one doesn't seem to line up should be the bad one.
No Chris.. when it starts to miss.. just loosen the line at the injector 1 at a time.. and retighten Be careful.. it can get messy.. have a rag handy.. the fuel is squirting out and your interrupting the flow.. When you get to a cyl. that DOESNT make a difference in the sound of the engine.. you found the "suspect" cyl..
Yes it does get messy,,,