My little Komatsu has a strange problem I can't figure out. Cranks fine first time but when you shut it off and restart it starts in what I call "limp mode" runs rough and won't rev up. After it runs for a while it will smooth out and runs fine. Any ideas?
More info required, has it always done this or just started recently? has anything been done to it recently? what have you done to try to correct problem? is the air filter new/clean and have you tried it without air filter? provide the serial number so the smart guys can give you an informed direction to proceed
air in the fuel lines will do what you describe. do you have those 'banjo-fittings' they need copper washers and tend to corrode a bit over time. easy to replace the copper washers and fix the seals if that's the issue. my JD has an Isuzu engine - 4 separate injector pumps, 4 injectors, both sets have common rails. It's got more than 10 of those 'banjo' fittings. I don't have fuel leaks, but if it sits for more than... 2-3 days, it will leak *some* of it's fuel back to the tank. so it pulls in a little bit of air at one or two of those fittings. I can't find it.. so whatever. the point being - it runs on 2 or 3 cylinders for the first 10-15 seconds and then gets fuel enough that they all fire up, and then it 'burps' the air out for the next 3-5 minutes. During that time, each burp is a puff of white or black smoke (no idea why the color varies on this start process) until after the 5 minutes, all the air is out and it's purring like a sewing machine. Sounds to me like you are describing a similar situation. if it bugs you a lot, go through your fuel system in detail and fix it. For those who think the smoke means something different, my oil stays nice and clean for about 10 hours after a change, and slowly darkens to black by about 50 hours. I change every 50 hours. And the coolant, now that I have fixed the radiator doesn't leak or lose level at all. no oil sheen at all either. Engine run cool and perfect after the odd starting process. it works very well, I'm not going to bother tracing it down.
Did it just started doing this.?? Does it get worse if it sits a couple of days.?? U could have a bleed back problem with the supply pump.?
I've heard if the oil in a diesel turns black it means the filter is doing it's job. Not sure I believe that. Also heard that any old oil that doesn't completely drain will turn new oil black. Black oil when changing it is the norm for diesels. 50 hour oil changes seem a little excessive and costly over time.
Yeah, I kinda winced at that. On some equipment that would be every week or every other week. I have never scrimped on oil and changes but I would think every 100 hours would be minimal and maybe 250 hours the norm. Of course, some of it would depend on the environment. Ash and fire I would cut that in half.
No, I get it. but I'm a homeowner, and my job is writing software. I don't use this that much. So 50 hours is at actually a couple of months. That all said, it's an approximation on the backhoe since the hour meter has failed, and I've not yet put on a new one. The backhoe gets changed seasonly - so April 21 (Start of Summer) and September 22 (Start of Fall) which makes sense because I put different grades in. So, for the little excavator, I'm doing it 50 hours currently, because I've been using it a LOT more than the backhoe, and it seems there's a pile of projects. Also, I'm being quite cautious with this machine - dumping the oil in the finals at the same time. My theory is that if there's gunk in there that needs cleaned out, frequent oil changes for a bit will go at least a little way towards doing that cleanout. I'll roll this one into the seasonal changes after this year is complete. The previous owner wasn't big on maintenance - so I'm hoping that a little extra might go a long way for me... make sense? I don't do 50 hours on everything all the time, I should have been clear about that. But I once a year change the oil in my lawn mowers, pressure washers, cement mixer, etc. Anyway, taking good care of stuff is important to me. So we all have hobbies, some are more expensive than others. playing with these machines is a load of fun for me. keeping them working well - it makes things rewarding when I know the work I put into the machine ends up in a nice new road or a trail to the lake or a new earthen shelf for a greenhouse. You know what I mean? Anyway, I'm sorry to have started this side chat on a thread where the guy is trying to solve his Komatsu runtime issues. I just started up my little JD 50 ex, and it's out there burping right now as I write and edit this post.