L4400 fuel gremlin

[Danielc8513]

Hi guys, I’ve got an L4400 and I’m in a bit of confusion here. I did search before so if there is a post on this, I apologize. Anyway, had a stick pop up and twist the fuel bowl mount...in turn this broke the nipples off the top for the line connections.

Purchased new fuel bowl assy, put it on and of course ran the battery down before I got it to crank. Hook up jumper cables, attempted to bleed the pump and then bled the injectors. Cranks right up, everything is tight... no leaks. But I noticed while using it the other day that it seemed to be blowing more black smoke than normal and also bogs down when it previously wouldn’t. Today, while on the trailer, I bled injectors again, mainly for the heck of it. (Ran it low of fuel last time I used it) Cranks right up, no issue with that-still excessive black smoke and now rattled on a few seconds more before shutting off after the key is turned. Changed air filters, no change in the way it’s acting. Haven’t had a chance to pull the disk to see if it’s still bogging but I’m going to assume it will with the excess of fuel. Lines are hooked up correctly also.

Any help would be much appreciated.

 

[100 td]

Fill fuel tank, recheck new filter seal and hose connections and re-bleed each injector when engine is running.
Other things like faulty injector/pump are possible but start here again to be sure.
EDIT: And make sure you have a good steady flow to the filter.

 

[thepumpguysc]

That IS odd.. "normally" black smoke is heavy unburned fuel & not enough air..
Run it WITHOUT the air cleaners & IF its not to much trouble.. disconnect the hose for the INTAKE. ON the manifold..
I've seen things like this before.. where the intake hose gets "smushed" from leaning on it & collapses under a load..
"SO IF" you remove it from the system, you should see an improvement.??
Good luck.

 

[lugbolt]

Temperature and barometer can play a role too. There's less oxygen in hot/humid low pressure air than there is in cooler/dryer air-and seeing how you are in Mississippi, and that cooler/dryer air came through last week....and now it's warmed up again, that could account for some of the black smoke.

Also if the muffler's got a lot of soot buildup, that can account for it too. So can valve clearance. So can dirty air intake. Excessive fuel in the crankcase lube oil can cause it too. Lots of things.

Had a customer complain that his L3830 runs fine in the spring, then it sits all summer until August when he's out tilling up food plots. Every August he calls me griping about excessive black smoke. Define excessive. Last time he used it, it was 55° outside and now it's 101° with a heat index of 124. Yeah it's gonna smoke a little in this kinda weather. Especially the non-turbocharged engines like the 4400 and his 3830. The turbo helps with big swings in weather and altitude but if you ain't got one, it can't help

 

[Danielc8513]

I will bleed injectors again, and try that. I’m also going to take the old and new housing apart side by side and see if anything jumps out at me. As far as smoking more during one season over the other, it’s never done it until the other day. Front end loader has smoke on it now that’s never been there in the first 480 hours.

I will check hoses and such again as well, hoping for something simple but with my luck, the pump has gone screwy or something. I haven’t had a chance to do anything to it since the other day, but I will report back then. If it sits idling for a few minutes, like while I was disconnecting the FEL so I could work on it easier, the idle speed increases as well. Oil still smells and looks like oil so I don’t think the pump seal is leaking anything either. Just a very odd situation to happen all at once and nothing significant occur to cause a change.

Tank is completely full as well, but I will check the lines going and coming from it as well. Thanks for the help guys.

 

[D2Cat]

Daniel, you sure you don't have some gasoline in your fuel?

This is the clue that made me think that. "But I noticed while using it the other day that it seemed to be blowing more black smoke than normal and also bogs down when it previously wouldn’t."

 

[Danielc8513]

Daniel, you sure you don't have some gasoline in your fuel?

This is the clue that made me think that. "But I noticed while using it the other day that it seemed to be blowing more black smoke than normal and also bogs down when it previously wouldn’t."

Yep, I filled it up and my truck out of the same pump after the last use. It’s full of diesel; Its definitely over fueling for some reason. Thursday I am going to tinker on it and will see what I find.