I've got a 322b cat excavator with around 11,000 hours on it. It ran good when I tried it out but now it pulls down and starts to miss when I put a load on it. I've changed all the fuel filters and air filters and let it fast idle for around an hour today so it up to temp. It ran fine for about 15 seconds then started to pull down with any load on it and miss. I no nothing about 3116 motors. The people that had it didn't do the best in care of their equipment.
If it was mine I'd be looking at the tank (has it be drained of water and sediment recently?), the tank cap (is it sucking a vacuum?), and the fuel feed line from the tank to the filter.
Would this engine have a little screen in the fuel line at the lift pump like a 3204? I had a problem where the engine would only idle and then die. Let it sit for 15 minutes and it would start and I could move the machine about 50' and it would idle and then die again. Took me over an hour to move it about an 1/8 of mile to where I could work on it. That little screen was plugged but could be removed and cleaned.
I did some reading last night and I think that's where I'm going to look today. The moment you put a load on it goes away. Give it a short rest and you can get a few seconds out of it till it starts pulling down and missing.
Check for air in the return fuel. It would be good if you could check fuel pressure too.
Not but agree with W Dave, guys doing some work for me had the same issue with theirs. When theirs started, they would remove a banjo bolt and inside was a screen. Cleaned it with some WD and it was ready to go again for hours. Said the tank needs cleaning and one of these days they will do it I think theirs was on the lift pump
Checked the inlet where it shows on trucks and no screen. I'm guessing someone has thrown it away. Do these have a electric or mechanical lift pump on them. The pump on the side of the block is the injection pump for the injectors right? It will probably go to a shop, I'm thinking maybe put a new set of injectors in it, probably hasn't had a set.
Transfer pump is in the governor where the throttle linkage is. The 3116 is famous for either transfer pump problems or leaking injector seats causing miss fire under load.
And follow post #2 also. The injectors are unit injectors, meaning there is no "injection pump", and they have to be set, or synchronized. I get the strong impression it's not a job for somebody who doesn't know what they're doing, and not cheap. The thing on the side of the block is the governor and transfer pump. On a truck at least, the transfer pump sucks from the tank and through the first filter, then pushes through the second filter and back to the governor, then on to the injectors in the head (at modest pressure). The mechanical transfer pump isn't very good at suction if there's any air at all. That's why a fuel return line check for air, and fuel pressure check are important. If it has good pressure and no air, THEN you look deeper.
Check fuel pressure and look for air in return cat has nice lil sight gauge for that. A vacuum gauge in suction line can can tell a lot keep us posted. Does exhaust seem normal white black ?
This has the stacked filters on one housing and a water separator filter down in front of the radiator. Is there a schematic available online that shows the route of the lines on one of these machines? Does it suck threw the water separator filter first? I need to get it home out of the woods to get some light on things. Thanks for the help.
Almost positive it sucks through the water separator and then to the transfer pump, and on to the filters if there aren't two separate filters. It's easy enough to figure out what goes where, take it apart and blow back to the tank and see what makes the bubbly noise. I don't think you'll need to go to the pressure side of the transfer pump, unless something majorly went wrong with the water separator. Be careful not to introduce dirt into the lines downstream of the filters.
Two injectors with broken springs and two others that are questionable. They would fill enough most of the time to run but miss under a load. The original safety bolts were still in it which means it hasn't had any upper end work since new. Hoping this fixes it won't know till next week when injectors show up.