Bleeding air from Ford 3930?

   / Bleeding air from Ford 3930? #1  
J

Jason280

Bronze Member
Joined
Apr 17, 2012
Messages
93
Location
Ga
Tractor
Kubota L4330
I've run into an odd issue with a Ford 3930 3cyl. We've had the tractor close to 10 yrs, and never had an issue until a couple weeks ago. While bushhogging, it started choking down a bit...and acted like it was running on half throttle. I assumed the filter was clogged, so I pulled it..looked fine. Went ahead and changed it, bled the lines, blew out the cutoff, and tractor ran normal....for less than an hour. Went back to running like it was on half throttle again, so I pulled the entire sediment bowl/filter housing. Noticed that fuel was barely trickling out of the cut off under the tank, so I drained all the fuel and pulled the cutoff assembly. The screen was completely clogged with algae/whatever you call it, so I went ahead and cleaned out the tank and screen. The sediment bowl was also fairly dirty, so I cleaned it as well. Reassembled everything, bled the lines, and its still running like its on half throttle.

It still acts like it has air in the line, so I am not sure if I'm missing some procedure for this particular tractor. I get good flow out of the cut off, and plenty of fuel out of the filter bleed screw. I first start bleeding the filter housing, then go to the injector pump bleed screw itself. Now, it doesn't have as much fuel pouring out as the filter housing, but I'm still getting fuel flow. I've also bled all three lines at the injectors...each individually, and then 1 at a time to make sure I am not missing something. Problem is, I'm still getting the same result...acts like it has air in the system.

The fuel filter looks good, I've never seen any trash/growth in the filter housing or filter itself (even with the old filter). All the O-rings were changed, so I am not sure what I am missing. Only thing left to do that I know is pull the individual line from the filter housing to the injector pump to check it, as well as all the injector lines to the injectors themselves.

Any other suggestions? Is there a special procedure for bleeding Fords?
 
   / Bleeding air from Ford 3930? #2  
Sucking air in the fuel line somewhere.
 
   / Bleeding air from Ford 3930? #3  
Unlikely (but still possible) that you are dealing with multiple issues. I would go back to the tank and reclean, rinse the water separator and element, and replace the filter again. A slug of gunk after the tank will wreak havoc.
Bad fuel and algae problems can require several attempts to clean out.
Next on the list would be to add an algaecide to your fuel tank, and storage if applicable. Also find out how water is getting into your fuel, and fix that!

If there is a secondary problem, I would suspect dry rotted fuel lines or bad connections. For rubber lines, bend them to check condition and for obvious cracks that could introduce air.
Good luck... Fuel issues can be a real pain.
 
   / Bleeding air from Ford 3930? #4  
Did u put the top oring UP IN THE FILTER HEAD.??
It HAS TO GO UP IN THE FILTER HEAD, or it’ll choke off the fuel..
 
   / Bleeding air from Ford 3930? #5  
Jason280 said:
I've run into an odd issue with a Ford 3930 3cyl. We've had the tractor close to 10 yrs, and never had an issue until a couple weeks ago. While bushhogging, it started choking down a bit...and acted like it was running on half throttle. I assumed the filter was clogged, so I pulled it..looked fine. Went ahead and changed it, bled the lines, blew out the cutoff, and tractor ran normal....for less than an hour. Went back to running like it was on half throttle again, so I pulled the entire sediment bowl/filter housing. Noticed that fuel was barely trickling out of the cut off under the tank, so I drained all the fuel and pulled the cutoff assembly. The screen was completely clogged with algae/whatever you call it, so I went ahead and cleaned out the tank and screen. The sediment bowl was also fairly dirty, so I cleaned it as well. Reassembled everything, bled the lines, and its still running like its on half throttle.

It still acts like it has air in the line, so I am not sure if I'm missing some procedure for this particular tractor. I get good flow out of the cut off, and plenty of fuel out of the filter bleed screw. I first start bleeding the filter housing, then go to the injector pump bleed screw itself. Now, it doesn't have as much fuel pouring out as the filter housing, but I'm still getting fuel flow. I've also bled all three lines at the injectors...each individually, and then 1 at a time to make sure I am not missing something. Problem is, I'm still getting the same result...acts like it has air in the system.

The fuel filter looks good, I've never seen any trash/growth in the filter housing or filter itself (even with the old filter). All the O-rings were changed, so I am not sure what I am missing. Only thing left to do that I know is pull the individual line from the filter housing to the injector pump to check it, as well as all the injector lines to the injectors themselves.

Any other suggestions? Is there a special procedure for bleeding Fords?
Click to expand...
If you had crap and corruption in the tank there is a good chance you have the same stuff in the filter head (the casting that holds the filter). Check the filter head where the fuel enters the filter.
 
   / Bleeding air from Ford 3930? #6  
   / Bleeding air from Ford 3930?
  • Thread Starter
#7  
It will be a couple days before I can get back to it, but I'll check the filter...makes sense that it might be clogged.

Looking at the schematic you posted, what is the point of the solenoid assembly/terminal (#75 & 76)?
 
   / Bleeding air from Ford 3930? #8  
It's been so since I've been around one of these that I really don't remember what it's for. Maybe someone else can chime in.
 
   / Bleeding air from Ford 3930? #9  
That’s an electric shut off solenoid..
There are 2 different pumps that went on the engine, depending on the year..

If your going to dig around in the pump, u had better know what yer doing.!!
 
   / Bleeding air from Ford 3930? #10  
Jason280 said:
I've run into an odd issue with a Ford 3930 3cyl. We've had the tractor close to 10 yrs, and never had an issue until a couple weeks ago. While bushhogging, it started choking down a bit...and acted like it was running on half throttle. I assumed the filter was clogged, so I pulled it..looked fine. Went ahead and changed it, bled the lines, blew out the cutoff, and tractor ran normal....for less than an hour. Went back to running like it was on half throttle again, so I pulled the entire sediment bowl/filter housing. Noticed that fuel was barely trickling out of the cut off under the tank, so I drained all the fuel and pulled the cutoff assembly. The screen was completely clogged with algae/whatever you call it, so I went ahead and cleaned out the tank and screen. The sediment bowl was also fairly dirty, so I cleaned it as well. Reassembled everything, bled the lines, and its still running like its on half throttle.

It still acts like it has air in the line, so I am not sure if I'm missing some procedure for this particular tractor. I get good flow out of the cut off, and plenty of fuel out of the filter bleed screw. I first start bleeding the filter housing, then go to the injector pump bleed screw itself. Now, it doesn't have as much fuel pouring out as the filter housing, but I'm still getting fuel flow. I've also bled all three lines at the injectors...each individually, and then 1 at a time to make sure I am not missing something. Problem is, I'm still getting the same result...acts like it has air in the system.

The fuel filter looks good, I've never seen any trash/growth in the filter housing or filter itself (even with the old filter). All the O-rings were changed, so I am not sure what I am missing. Only thing left to do that I know is pull the individual line from the filter housing to the injector pump to check it, as well as all the injector lines to the injectors themselves.

Any other suggestions? Is there a special procedure for bleeding Fords?
Click to expand...
"...Now, it doesn't have as much fuel pouring out as the filter housing, but I'm still getting fuel flow...."

What does that tell you?
 
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