POTD will drag over to at least another day. . . I bought a Case 580C backhoe in 1996 as the cost to job out a number of dirt moving projects on my "itinerary" far exceeded the cost of the used backhoe. I finished up the majority of the projects by 2008, but kept the backhoe. They can come in handy digging the occasional trench or punching a hole to make some stuff go away!
We're looking at having a pond dug, the contractor suggested punching a few test holes to see where the water table is. So, time to work on the Case 580 that hasn't been started in 8 years . . .
Full disclosure, I'm not a mechanic though I did work for an auto company. When last used, it was struggling to get above 1800 RPM (red line is ~2200 RPM). I figured it's air, fuel and compression to make it run (no glow plugs). The air filter was clean, and since it ran, my assumption was that I had compression. I'd bought the Case in 1996 and put about 200 hours on it by 2008, and admittedly had never changed the fuel filters, my bad. Here's the process:
I opened the sediment bowl/drain which ran clean, but ran a cup of fuel out anyhow. No rust or water there. Shut the fuel shutoff and cracked the plug on the upper filter for vacuum release and the the lower filter to drain the system. Replaced the filters. Left the drain plug off on the upper filter and opened the fuel shutoff. Ran in the upper plug once fuel (with no air bubbles) was running out. The next step is to crack the tube nuts at the injectors, hit the starter for 10 seconds until fuel is running out, then tighten the tube nuts. In my laziness, I "wished" this step away, crossed my fingers and fired up the Case. It ran "okay", though I'd only get about 1800 RPM's out of it, but at least it ran continually. Not having any projects for the Case on the horizon, I topped off the fuel tank (recommendation from a former coworker; minimizes air in the tank and accumulation of rust), added diesel fuel conditioner, and walked away. . .
Hard to see, but the sediment bowl valve is in the middle of the pic, fuel shutoff at the top.
Upper/lower fuel filters and injector pump
Fast forward (finally) to yesterday. I figured before trying to fire it up, I'll do the right thing and crack the tube nuts at the injectors. Pulled the exhaust, air filter can and the hood. Yeah, pulling the 4 bolts for the hood gives total access to the top of the engine, I should have done that when I first changed the filters. Something about taking one step back to take 3 forward. I was lazy back when I'd changed the filters; by not pulling the hood the injector tube nuts are really tough to get to. Without the hood, easy peezy.
Looks kind of naked without its hood, but it's a whole lot easier getting to the engine!
I didn't change the filters, but ran the sediment bowl (no crud or water), ran fuel out of the bottom filter which was clean. Cracked the tube nuts and hit the starter.
Tube nuts loosened
Tube nuts after running the starter; definite evidence of fuel through the lines
Tightened the tube nuts, stuck the exhaust back on and crossed my fingers. It fired up after a few seconds! I left the engine idling at ~800 RPM's, let it run for 30 seconds thinking/hoping I was good to go. Then it started running rough, RPM's varying from just about stalling out to 1000 RPMs. Long story longer, I fired it up a few more times; it'll run smoothly for about 20 seconds, stepped on the gas and got to 2000 RPM's, then starts struggling again.
Okay you diesel mechanics out there; any ideas? My assumption is a problem with fuel delivery. If it runs at all (I was able to take it up to 2000 RPM's), my assumption is I have compression. The air filter is clean also. And yes, the fuel in the tank is 8 years old. Should I drain the tank and start with new fuel? These are my thoughts moving forward though I'll be consulting a buddy who's a very good wrencher:
1) Repeat the tube nut air evacuation process. Maybe(?) there's still some air in the lines? The injector lines run uphill from the pump to the tube nuts, then downhill to the injectors. I'm thinking if I crack the nuts and let it set for a while, air should move to the tube nuts. Then run the starter with the lines cracked and chase the air out?
A look down the injector lines. The tube nuts are at the high point so I'd think air would migrate to that joint. If I had air between the tube nut and injector, leaving the line cracked would let the air move up to the tube nut joint?
2) Start pulling fuel lines one by one to see if they're plugged. Again, I'm assuming a fuel delivery issue. I'm thinking if the engine runs for 20 seconds, then starts to struggle, I've let it set long enough to have some fuel supply, but I'm using it up in 20 seconds and the system runs lean?
3) Pull the injectors and check their function. I'll need to do some research on this; not currently in my skill set. On the other hand, if it was a stuck injector, why would the engine run fine for 20 seconds, then have an injector stick?
Any advice from you wizards out there would be appreciated! Thanks in advance for any advice!
Bruce