Non-starting D3B

Got a D3b that was running fine, serial 24y27267..45v36373..3204. Unloaded it off the trailer, walked it about 30 yards, and the engine just died like it ran out of fuel. Checked the tank and still had roughly 30 gallons. When I tried to start it, it would pop for about 3 seconds then die. Did the basics—put on a new fuel filter and air filters, bled the fuel lines while cranking. The hand pump was frozen. Tried starting with ether but got nothing. After maybe 6 cranks it would start for 3 to 5 seconds and die again. Ether spray won't keep it running. I'm getting fuel to the injectors while cranking, though it takes 4 to 6 tries before it pops. Where should I look next?

Sounds like a fuel supply issue to me. I'd check the screen on the inlet line—it's probably clogged. You'll find it tucked inside that long hex fitting where fuel enters the transfer pump. Had the same thing happen with a 931C not long ago.

The check valves in the transfer pump might be shot and not holding pressure well.

Still can't get it to start. What's the fuel pressure spec for a D3B? Seems like it's not turning over fast enough to push fuel to the injectors.

What have you actually tested or replaced so far? Are you seeing any smoke when it cranks?

I'd look at the starter. My buddy's 931C had the same kind of problem—turned out to be a plugged screen on top of a weak starter. The engine was turning just enough to get some fuel in and make a bit of smoke, but it wasn't spinning fast enough to actually fire. He put in a new gear reduction starter and it made a huge difference. He still needed a couple of shots of starting fluid, but then it fired right up and has been starting fine since. Swapping out a starter is a pain to do, but the gear reduction one is about 20lbs lighter and easier to get in than what was on there.

When it does fire up, there's a lot of black smoke coming out. I had the starter checked at a shop and it tested fine.

Probably doesn't have enough heat from cranking too slowly.

Transfer pumps were known to lose pressure once the check valves got worn out. If you've got a priming pump, try working it while you're cranking. They usually fire up that way, and you should see around 30 psi.

I'd say the serial number might have a typo in it, but I don't think this model would come with a manual priming pump anyway. My 86 931B doesn't have one. A friend's 931C that I helped get going recently just needed to crank faster after we cleaned the screen. It still needed some starting fluid even though it was showing smoke.

We've got a D3B with serial 24y01411 and engine 45v36375. We've tried just about everything except pulling the fuel pump for testing. Could someone look up the part numbers for the complete fuel pump assembly?

That black smoke when you're trying to start it is what concerns me. Did you try disconnecting the hose from the air cleaner at the head?

When you say the starter checked out good, did they test it under load? I ask because my buddy had a 931C that would turn over fine but was way slower than it should've been. A new starter got it spinning much faster than before, though it still needed a couple small shots of starting fluid to get going.