CAT 252B3 starts, sputters, dies

[Boreal]

I have a 2012 CAT 252B3 with 2,400 hours on it and C3.4 engine s/n TNK01281 that starts, sputters, and dies like it's starving of fuel. Today it was 35F and sunny. It started great as always. Idled for about 5 minutes to warm up and then I noticed it was slightly vibrating. I got in the cab to start pushing snow and when I throttled up slightly, it started blowing smoke and sputtering. I shut it down to investigate and found my fuel screen (Napa 3972) was only 1/4 full. I then remembered I drained the separator after shutting down and refueling on Saturday. So my initial thought was maybe I should have cycled the lift pump more before running it and I got some air in the system. I didn't drain that much from the separator but it seemed like a good place to start. And not sure that it would have started and idled for 5 minutes with air but seemed like a logical first guess.

I ran the lift pump through 5 cycles. The screen got to about 5/8s full and the machine started right up. Ran for about a minute at idle then sputtered and smoked again. I noticed the screen was back down to 1/4 full so I thought maybe it was sucking air. I tightened all the hose clamps, unlocked the fuel cap, and started it again. She started right up and again idled fine for a minute then sputtered and died.

I thought maybe I had air above the filter so I cracked the fuel lines at the injectors and spun it over. I'm working alone so I couldn't watch the fuel come out but each injector fitting looked equally wet so I figured I was getting good fuel to the injectors. Again I cycled the lift pump a few times. It started right up, ran for a minute, and died. Now the fuel level in the screen doesn't change anymore. It holds around the 5/8s full level even while running so that seemed good.

I had a new fuel filter and figured it was a good next step. I hated replacing the other one since it only had 50 hours on it but figured it was worth trying since I did get a tablespoon of water out when I drained the separator on Saturday. Replaced the filter, cycled the lift pump, it ran for a minute at idle and died.

I drained the fuel from the old filter and didn't see any obvious water or debris. I'm not sure what my next step should be. I'm confused why the machine always starts right up after dying from what seems to be fuel starvation.

I had some similar fuel-related issues in this thread early this winter https://www.heavyequipmentforums.com/threads/cat-252b3-losing-power-when-below-freezing.97832/ but that was when temps got cold and today was actually above freezing. The machine has been working great since then. I know I've ran the machine when temps were in the 30s and I've had the machine and fuel fully warmed up after hours of work and never had an issue so I can't imagine this is temp related.

I haven't blown air through the fuel line back to tank yet to make sure there's no blockage. I was going to do this when the screen was losing fuel level but now that it is stable, I figured there was enough fuel getting to that point. Maybe I should go do that anyhow.

I do have a generic inline fuel pump that I thought about adding temporarily in place of my screen before the filter just to see what happens and hopefully rule out the lift pump. Is that a good next step or is there anything else I should try first?

TIA

 

[Nige]

Try removing the complete fuel pump/filter/water separator assembly and disassemble. Poke a piece of wire through all the ports in the head and blow them out with conmpressed air.
Then blow your fuel lines back to the tank with compressed air.
When was the last time water/sediment was drained from the tank.?

See Post #15 in this thread - https://www.heavyequipmentforums.com/threads/cat-277b-skid-steer-cranks-but-wont-start.99433/

 

[Boreal]

Try removing the complete fuel pump/filter/water separator assembly and disassemble. Poke a piece of wire through all the ports in the head and blow them out with conmpressed air.
Then blow your fuel lines back to the tank with compressed air.
When was the last time water/sediment was drained from the tank.?

See Post #15 in this thread - https://www.heavyequipmentforums.com/threads/cat-277b-skid-steer-cranks-but-wont-start.99433/

Yeah, I've done that filter head cleaning a few months ago. Found a leaf and that fixed one of my issues then. My thought now was the screen should keep it from getting plugged again. Separator was drained on Saturday. Fuel tank was warmed and flushed a couple months ago after finding the leaf.

I just went back out to blow air through the fuel line back to tank. I got no air flow which is confusing because it was running. In the past I know I've easily heard the fuel in the tank gurgle but this time I only got air pressure coming back at me. Very strange since the pump had to be getting some fuel to run after I changed the filter. And I did have the fuel cap open. I've learned my lesson from that the hard way in the past.

Since I have no air flow back to tank, it seems like that is where I need to start. But that doesn't really make sense that it ran...

 

[Nige]

Yeah, I've done that filter head cleaning a few months ago.

What about the O-Ring in the separator bowl.? Is that in the correct place.?

Since I have no air flow back to tank, it seems like that is where I need to start. But that doesn't really make sense that it ran...

It could easily be something that is acting like a non-return valve that allows fuel to (somewhat) flow in the forward direction but won't allow anything to flow in the reverse direction. A distinct possibility is the inner lining of the fuel supply hose coming apart.

 

[Boreal]

What about the O-Ring in the separator bowl.? Is that in the correct place.?
It could easily be something that is acting like a non-return valve that allows fuel to (somewhat) flow in the forward direction but won't allow anything to flow in the reverse direction. A distinct possibility is the inner lining of the fuel supply hose coming apart.

The fuel filter and separator are one piece and I just replaced it today so I'm ruling that out.

I'll pull the fuel line tomorrow and see what I find. Now I just need to find a very tiny person to squeeze back there and pull it off the tank

 

[heymccall]

Looks like tank draw pipe is accessed via Cab UP.


And, have you considered draining the sediment/ water from the fuel tank?

 

[Boreal]

And, have you considered draining the sediment/ water from the fuel tank?

Thanks Heymccall! I didn't even think of lifting the cab! I'm sure that'll make it easier.

I did drain the tank a couple months ago but I'd like to do it again in a couple months or so when the machine is completely thawed out. I did my best to warm it before draining but still had to chip through ice after removing the plug.

 

[Nige]

The fuel filter and separator are one piece and I just replaced it today so I'm ruling that out.

Doesn't your fuel/water separator look like Area C in the illustration HMC posted above, an element with a clear plastic bowl screwed to the bottom of it.? If so, then the O-Ring goes between the two parts. See Post #15 of the thread I linked above for more detailed photos.

 

[Boreal]

Doesn't your fuel/water separator look like Area C in the illustration HMC posted above, an element with a clear plastic bowl screwed to the bottom of it.? If so, then the O-Ring goes between the two parts. See Post #15 of the thread I linked above for more detailed photos.

No, mine is a 361-9555 that is a one piece

 

[Boreal]

So the problem was ice. The tank must have finally gotten warm enough to melt some of the ice in it and it refroze blocking the suction inlet.

I started a little fire under the machine to thaw it out, ran it for a few hours to get it warm, and fully drained the tank again. Added fresh known good fuel, ran it again the next day for a few hours and drained it again. So far no problems but I did get a lot of water, leaves, debris, and even an old fuel cap spring out of the tank while flushing.

I'm still getting some water in the separator so I'll likely flush it again next time I can get the tank warm enough. We'll probably have some days above freezing in a few weeks. Wasting a lot of fuel and still not sure how I got water in there. Maybe it happened when I pressure washed the engine bay last fall. There was a couple inches of mud coating the floor of the bay from all the summer work. I can't imagine how pressure washing would get that much water in the tank but it's all I can come up with.

 

[Nige]

Wasting a lot of fuel and still not sure how I got water in there.

It could be nothing more complicated than condensation in the tank above the level of the fuel caused by the "hot" fuel coming back down the return line. It's the same reason that any machine that does not run 24/7 should ideally always be parked up after working with the fuel tank as full as possible. I guess with all the material you got out of the tank it also begs the question as to when was the last time the water & debris was drained.?

 

[Boreal]

It could be nothing more complicated than condensation in the tank above the level of the fuel caused by the "hot" fuel coming back down the return line. It's the same reason that any machine that does not run 24/7 should ideally always be parked up after working with the fuel tank as full as possible. I guess with all the material you got out of the tank it also begs the question as to when was the last time the water & debris was drained.?

Yeah, I've only had it for the last 1-1/2 years and drained it 3 times now but all in the winter.

Now that I know what a problem water can be, I'm planning to start draining it every spring and fall when things aren't frozen which will be about every 250 hours. And draining my bulk tank as well.

 

[Nige]

I'm planning to start draining it every spring and fall when things aren't frozen which will be about every 250 hours.

If you had an O&M manual you might be aware that it's recommended to drain water & sediment from the fuel tank every 50 operating hours or weekly, whichever comes first...........

 

[heymccall]

You can add this to the bottom of your 361-9555 filter.


It's an integral part of that filter's performance.
Like shown in the parts book.

 

[Boreal]

If you had an O&M manual you might be aware that it's recommended to drain water & sediment from the fuel tank every 50 operating hours or weekly, whichever comes first...........

I wish there was some way to get a valve down there so I could just drain water and sediment. Removing the 1" NPT plug is kindof an all in situation on draining everything. Even when the tank is basically empty for running the machine there is still 2-3 gallons in the bottom.

@heymccall I'd love to add that separator. When I look up the part on parts.cat... It isn't see-through like the one you posted. Instead, it's solid black. Is there a different option to get the clear one?

 

[heymccall]

Beats me as to what you're seeing. I haven't bought one in a while. Used to have a moron here who would toss it with the old filter.

The bowl and filter design belong to Stanadyne, part of they're Keyway filter system. That style is the FM100 series. That bowl can be bought other places. Most of my Deeres have that OEM, and I've also gotten it thru Napa (hard to find number, though.)
Also, Deere RE51650

 

[Boreal]

Beats me as to what you're seeing. I haven't bought one in a while. Used to have a moron here who would toss it with the old filter.

The bowl and filter design belong to Stanadyne, part of they're Keyway filter system. That style is the FM100 series. That bowl can be bought other places. Most of my Deeres have that OEM, and I've also gotten it thru Napa (hard to find number, though.)
Also, Deere RE51650

I called CAT and they said it is clear. Apparently, the parts site doesn't always show correct parts images.

 

[heymccall]

I get same pic at Cat.

My wholesale price for #4924 at Napa is $63.13 (I buy a lot there)