injection pump MF30 prime air bleed

greasyBob

Member
I have a MF 30 /3165 Tractor been sitting a while, its a perkins 4 cylinder 4.203 with the lucas Cav DPA injection pump I changed the fuel filters and trying to bleed the fuel lines . turning over I can get plenty of fuel spray out of bleeders on side of pump ,but no fuel coming out of 4 pipes going out up to injectors what can be the problem and what can i try to get fuel flowing. , Thanks
 

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Hmmm. Once it's full to the bottom bleed screw, I think you're done with that bleed screw and onto trying to fill it to the top one. You could even pour or pump diesel into the top bleeder. Do you know about manually working the lift pump when the tractor isn't running? I've heard that these are finicky to prime and had to crank forever last time I did fuel filter on my 175.
 
I have a MF 30 /3165 Tractor been sitting a while, its a perkins 4 cylinder 4.203 with the lucas Cav DPA injection pump I changed the fuel filters and trying to bleed the fuel lines . turning over I can get plenty of fuel spray out of bleeders on side of pump ,but no fuel coming out of 4 pipes going out up to injectors what can be the problem and what can i try to get fuel flowing. , Thanks
If it has been setting a while you likely have some internal parts of the injection pump that have stuck.
 
If you want to try a couple things before taking pump apart tap on side gently soft head mallet not top cover will leak can also loosen kill cable and move lever on injection back and forth swiftly
Bit if fuel smells like paint thinner your probably out
Of luck
 
I have a very similar problem. I'm working on a 1960s MF40.
I replaced the fuel tank and then it sat for a month or 2, and now it's not starting.

This is what's happening: per the manual I will bleed the system (Up to the injection pump) with the manual pump lever (and I will bleed it very well to make sure there's no air in the lower or upper injection pump vent). Then when I turned over the engine with the starter to bleed the injector lines, no fuel comes out of them. Then if I open the lower vent on the injection pump lots of air is comes out. Then again, in the upper chamber of the injection pump Has lots of air, sometimes there's almost no fuel in it only air.

Is my injection pump sucking in air? Where / how would this happen?

I disassembled the upper section of the injection pump and the meeting valve is not stuck or clogged, everything is working well In the upper chamber.

I don't see any fuel leaks in the system.

What ideas do you guys have?
 
I have a very similar problem. I'm working on a 1960s MF40.
I replaced the fuel tank and then it sat for a month or 2, and now it's not starting.

This is what's happening: per the manual I will bleed the system (Up to the injection pump) with the manual pump lever (and I will bleed it very well to make sure there's no air in the lower or upper injection pump vent). Then when I turned over the engine with the starter to bleed the injector lines, no fuel comes out of them. Then if I open the lower vent on the injection pump lots of air is comes out. Then again, in the upper chamber of the injection pump Has lots of air, sometimes there's almost no fuel in it only air.

Is my injection pump sucking in air? Where / how would this happen?

I disassembled the upper section of the injection pump and the meeting valve is not stuck or clogged, everything is working well In the upper chamber.

I don't see any fuel leaks in the system.

What ideas do you guys have?
Fuel leaks anywhere? Could be letting air in at those points
 
greasyBob, my 135 diesel takes quite a bit of turning over to get fuel from the pump to the injectors. This even after I can get the manual lever on the fuel pump to squirt fuel out past the front tire
 
I am sure I found the problem some surface rust on the metering valve has stuck it shut throttle linkage does not move it and it's stuck at zero fuel output, I'm spraying WD to free up the metering valve. Gaskets are coming then I'll put everything back and know for sure
 

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I have a very similar problem. I'm working on a 1960s MF40.
I replaced the fuel tank and then it sat for a month or 2, and now it's not starting.

This is what's happening: per the manual I will bleed the system (Up to the injection pump) with the manual pump lever (and I will bleed it very well to make sure there's no air in the lower or upper injection pump vent). Then when I turned over the engine with the starter to bleed the injector lines, no fuel comes out of them. Then if I open the lower vent on the injection pump lots of air is comes out. Then again, in the upper chamber of the injection pump Has lots of air, sometimes there's almost no fuel in it only air.

Is my injection pump sucking in air? Where / how would this happen?

I disassembled the upper section of the injection pump and the meeting valve is not stuck or clogged, everything is working well In the upper chamber.

I don't see any fuel leaks in the system.

What ideas do you guys have?
Hello da 17 , Assuming you have plenty of fuel in the tank and the connection at the tank is on and not leaking,. then you have bleed the filters with the hand pump and closed off the bleeders on top the filters,. If you Keep working the hand pump you should* see fuel dripping out from where ever the air is coming in like a fitting or line connection
 
I am sure I found the problem some surface rust on the metering valve has stuck it shut throttle linkage does not move it and it's stuck at zero fuel output, I'm spraying WD to free up the metering valve. Gaskets are coming then I'll put everything back and know for sure
Bob, try Kroil. Best ever at freeing stuff
 
Hello da 17 , Assuming you have plenty of fuel in the tank and the connection at the tank is on and not leaking,. then you have bleed the filters with the hand pump and closed off the bleeders on top the filters,. If you Keep working the hand pump you should* see fuel dripping out from where ever the air is coming in like a fitting or line connection
Well when I was first trying to bleed it the fuel tank was close to empty, but still lots of fuel was going to the injection pump. But I thought maybe it's also sucking air, so I added 5gals of fuel, bled it, but it's still doing the same thing... but could it be that there was just so much air in the line that it I need to bleed a lot more?

Also regarding the fuel filter bleed screw, is it the bolt that's circled in red in the picture? (The bolt circled blue removes the filter).
I tried to remove all the air out of the filter via the red circled bolt, is that correct?

Thank you!
 

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Well when I was first trying to bleed it the fuel tank was close to empty, but still lots of fuel was going to the injection pump. But I thought maybe it's also sucking air, so I added 5gals of fuel, bled it, but it's still doing the same thing... but could it be that there was just so much air in the line that it I need to bleed a lot more?

Also regarding the fuel filter bleed screw, is it the bolt that's circled in red in the picture? (The bolt circled blue removes the filter).
I tried to remove all the air out of the filter via the red circled bolt, is that correct?

Thank you!
yes, the bolt that's circled in red in the picture is the bleed screw
 

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