Case 430 stumbles and blows white smoke at high throttle.

[jacobd]

Just had a problem pop up I'm hoping someone can help with. Machine was running fine, digging out a stump, nosed down at a steep angle and heard a very slight miss. I backed out to level ground and played with it some. At this point once you move the throttle above halfway or so the engine begins to miss and stumble and blow lots of white, acrid smoke out of the exhaust. It Idles fine and sometimes you can slowly sneak the throttle up and it will keep running correctly but usually it begins to miss. I suspect I may have run low on fuel as it was low enough to trigger an audible alert at one point, but it quickly went away and I forgot about it and kept working like a dummy. I added what fuel I had on hand (2 gallons or so) with no difference. Also I have no warning lights on in the instrument cluster.

Could I have sucked some air or trash into the lines and maybe it's starving for fuel now? What can cause these symptoms? Thanks for any help.

 

[Tags]

You probably just sucked up some water or trash off the bottom of the tank. Change the fuel filter(s) and see if that does the trick.

 

[xgiovannix12]

2x on fuel filter replacement

 

[Delmer]

It's either starving for fuel, or the fuel is getting aerated from a suction leak and/or plugged filter/screen/fitting, or the timing mechanism of the pump got screwed up somehow. The pump is the worst possibility, I have no idea what kind of pump you even have, and even if I did, I couldn't fix it, but I still have the gall to suggest it as a possibility.

The aerated fuel and starving for fuel are easy to check for, a vacuum/pressure gauge in the intake and a clear hose in the return will show what's up. IF both are good, then your pump is SCREWED.

 

[jacobd]

Looks like it's problem solved. No one in town had the inline filter in stock but I changed the fuel/water separator and added 10 gallons of fuel to the tank. Ran it around some and it's humming along just like it used to. Fuel that I got out of the separator filter looked just fine. Maybe the lift pump is getting weak and didn't want to suck up the last little bit in the tank? I have no idea. I'll definitely be more vigilant in making sure it doesn't run low on fuel in the future though.
Here's a quick pic of it back under the shed.

 

[xgiovannix12]

the pump either works or it dont. I try not to run anything under 1/2 to 1/4 tank