L3400 Stalling at High RPM

[Kleus]

Problem: L3400 stalling and dies at 2000 rpm
Starts fine, can run at 1000 to 1500 rpm indefinitely but when rpm increased to aroun 2000 rpm it dies.
What I’ve done so far:
Drained fuel tank blew our fuel lines and replace fuel filter. No change
Siphon our new fuel attempting to get any sludge, blew out fuel lines. No change
Replaced fuel pump. No change
Replace fuel shut off solenoid. No change
Bled injectors multiple times. No change
Bypassed fuel filter assembly. No change
New air filters. No change
Fuel conditioners. No change
Approximately 500 hours in tractor. Bought it new.
Don’t know what else to do.
Any thoughts would be appreciated.

 

[North Idaho Wolfman]

Sounds like the tank is not venting.
Run it up till it starts stalling then while running open the fuel cap.

 

[Kleus]

I have tried unscrewing the tank cap with no luck.

 

[whitetiger]

With the fuel filter out did you blow out the Inlet fitting in the filter head? That is where debris usually gets caught. Blow thru it backward to check it.
It that is clear, hang the hose to the fuel filter into a 5-gallon bucket and let 3 or 4 gallons of fuel run out while watching the flow. You very well could have something in your tank that floats and gets sucked over the outlet.

 

[Kleus]

I appreciate that. However that’s been tried too. It’s really baffling. Is it possible a fuel line could be collapsing under high rpm?

 

[whitetiger]

I appreciate that. However that’s been tried too. It’s really baffling. Is it possible a fuel line could be collapsing under high rpm?

It is possible but very, very unlikely.

 

[85Hokie]

I appreciate that. However that’s been tried too. It’s really baffling. Is it possible a fuel line could be collapsing under high rpm?

Is it possible to bypass the tank all together? Diesel container high and place a quart of fuel in it, run it and then open up the throttle, see what happens! You have covered everything else it seems.

 

[North Idaho Wolfman]

Your fuel couldn't have gotten contaminated with gasoline could it?

 

[Kleus]

Well I changed the fuel lines yesterday. I also noticed that the air/fuel bleeder dial cock had broken off. There was a little bit of the threaded stem sticking out. I was able to get pliers on it and turn it about a quarter turn to the right. Then I could no longer grab it. I cranked it as usual and throttled it up. OMG it didn’t stall. I don’t know which thing I did that solved it now. But I was able to drive it about a mile at full throttle. Now as soon as it stops raining I can do some work. Thanks everyone...

 

[whitetiger]

It was almost certainly the bleeder valve being open 1/4 turn that was causing your problem.

Glad to hear it is running properly!!!!