MF runs for 7 min dies air in fuel line ! Help!

MFDan1

New User
I have a MF 220-4 1980. I was blowing out my driveway for about an hour and then all of the sudden she died. Won t restart. Bleed the fuel system air in the lines; get it to run for about seven minutes... dies. I replaced the fuel filter and all of the fuel lines and it s still doing it. Seems like vapor lock! It s a gravity fuel system. After it dies fuel will not come out the bleed screw. Takes some time to cool down and it will bleed... bleed the screw, get the air out... bleed the injectors.... eventually starts. Runs for about 7 min and DIES!! This makes no sense to me. Please help! I need this thing to work the snow is getting deep!!
 
Sounds like you have a restriction in
your fuel line, injection pump is trying
to suck fuel! Try taking the fuel line
off at the injection pump and see how
fast it pours out, if hardly comes, give
a little air back up in the line to blow
back the restriction! Also as I'm
thinking of it, when was the last time
you changed fuel filters?
 
Sounds like the tank is empty. Then does fuel flow from the line at the tank then the other end of the line by the filter then continue on till you get to the pump. Also is there a low pressure pump piggy backed to the injection pump to push fuel from the filter to the secondary on up to the injection pump.
 
I don't know anything about your
particular tractor, but here's an idea for
you based on a past problem I encountered
with a CAT branded Perkins....and I know
MF liked Perkins.

IF it has a turbo, and a flame start style
intake heater, with the fuel line going to
it, change the heater.

What can happen with those is the fuel
valve in the heater goes bad. When the
engine is loaded, and the turbo
pressurizes the intake manifold above
whatever pressure it's taking to leak past
the valve, it puts air in the system.

From there you may, or may not have to
bleed the system for it to start and run
again....until intake pressure hits that
magic number and she shuts down again.

In my case the engine would restart
immediately, run all day making a little
bit of air, but simply wouldn't carry the
compressor at a full load.

I had this happen on an engine driven air
compressor, and nearly lost my religion
before I figured it out.

Good luck.
 

It sounds like either you have gravity shut off there or your tank outlet is plugged. with the tank outlet line free to run will fuel run a steady stream for two minutes?
 
What do you mean by gravity shut off? I?ve let it
flow for a while when I cleaned the sediment bowl.
 
I filled the tank after the first incident. It goes tank to sediment bowl to fuel filter to injection pump to injectors. Super simple I just doesn?t make sense. Temperature is definitely part of the equation.
 
After the first incident I added some diesel boost. The fuel is new and it should be winter blended diesel. It has happened at all temps from o to plus 30
 
(quoted from post at 05:36:06 02/10/20) I filled the tank after the first incident. It goes tank to sediment bowl to fuel filter to injection pump to injectors. Super simple I just doesn?t make sense. Temperature is definitely part of the equation.

Dan, here you say that the fuel goes through, initially you said when you bleed it you are getting a lot of air out. Which do you have air or fuel?
 
My trencher has a Ford engine with no lift pump like you describe. It would run just fine as long as the tank was full. When it got down to half it wouldn't ake power and eventually die. Couldn't find anything wrong so I added an electric fuel pump. That cured it. The tank is at the same level as the engine and when down to half full the fuel level was below the injector pump. I figure the pump in the injector pump just couldn't pull enough fuel. Maybe the cold fuel is just thick enough to not flow causing the same kind of problem.
 
My 231 Massey would quit like that. I found some grud in the shut off valve on the bottom of the fuel tank. It would restrict the
flow of fuel. A guy on here suggested to check it and it solved the problem.
 
Both! Initially air. Then I bleed it get the air out get her going. Runs for about seven minutes. Dies. Open up the bleed screw on the injector pump...nothing comes out...no fuel. Let it cool
down, giggle the fuel line and slowly fuel starts to come out the bleed screw on the injector pump. I then start cranking and bleed each injector at the motor until it starts back up. Same thing
runs for seven minutes ish, and dies... Repeat
 
That seems like a good solution. Can you recommend a pump? My gas tank is above the injector so gravity should be working here!
 

Dan your problem is the simplest and most common of diesel problems. It is not getting fuel. Since your tank is above the injection pump there is no need to put a fuel pump in. Most likely as double R said it is at the fuel shut-off at the bottom of the tank. You would do best, however, to do this SYSTEMATICALLY. It is not adequate to have some fuel at the various places that you are checking. You need to have steady flow for two minutes. So open a place that is easy to get at and check flow. If it slows to a drip your obstruction is up-stream of that point. Don't remove the tank unless you need to.
 
I agree with Showcrop, check your tank valve, you probably have something in your fuel tank that floats free when you aren't running the
engine, lets you bleed the system, then slowly draws down and replugs the outlet when you get it running. I've seen it many times.
 
Since your tank is above the i-pump it should work as is. I do agree that it's most likely crud in the tank. I had that on my JD4430. I drained the tank, removed the valve and flushed it with E85. Put the valve back in and added a gallon of E85 and let it sit a day. Drained that, then put a 1/4 tank of diesel in. To that put in a bottle of biocide to kill any algae still in there. Let sit a day and ran it. Worked for me.

If you do want to add a lift pump, any electric pump should work. I got mine from Ebay.

cvphoto4765.jpg

Pump
 
Your right, I had to drain tank and take the valve off and found it had some crud in it. It didn't totally block the flow of fuel but restricted it enough to cause problems especially when I was working the tractor hard. I cleaned it out and never had the problem again, I have since traded the tractor in on a new one. I'm not saying that's your problem but could be something to look at if all else fails.
 
If you can take the fuel line loose at the tank and check the flow. Good chance you will find the flow slows or stops. Also try it with the fuel cap off it also could be the tank vent
 
worked for a Massey dealer in the 70s when the 2000 series was made and we had a lot of that and found rubber bands in the fuel tank that when they got hot would turn to snot and plug the fuel flow let the tractor cool it would for a short time long shot but check all lines
 
First off I just want to thank all of you for the awesome suggestions. Im getting close here, and I think you guys are correct in thinking there is something in the tank. Tonight I bled her got her
running, she ran for 17 minutes like a top and then when it began to die I opened the fuel cap. No change in anything. I then opened the bleed screw on the injector pump...no flow with the fuel
cap off. I left it open for about 5 minutes with no luck.. So I'm thinking Im going to take off the sediment bowl and drain the tank and see what happens. Im hoping whatever it is will flush out.
My sediment bowl is below the shut off. Im thinking once its emptied out ill take that valve off to get a better look. Once its emptied any suggestions on a efficient way to flush it out? Thanks
again!!
 
(quoted from post at 18:50:05 02/10/20) First off I just want to thank all of you for the awesome suggestions. Im getting close here, and I think you guys are correct in thinking there is something in the tank. Tonight I bled her got her
running, she ran for 17 minutes like a top and then when it began to die I opened the fuel cap. No change in anything. I then opened the bleed screw on the injector pump...no flow with the fuel
cap off. I left it open for about 5 minutes with no luck.. So I'm thinking Im going to take off the sediment bowl and drain the tank and see what happens. Im hoping whatever it is will flush out.
My sediment bowl is below the shut off. Im thinking once its emptied out ill take that valve off to get a better look. Once its emptied any suggestions on a efficient way to flush it out? Thanks
again!!

What I do myself is just take one of those $3.99 transfer siphons and siphon fuel out while working it slowly around the bottom until the fuel runs clear.
 
Well folks, thanks again for all the advice. I took the valve off above the sediment bowl. Let her flow for a bit; then I looked in the shut off valve and there was a round beetle looking insect jammed in the inlet! Cleaned it out with some tie wire and it seems like she s good as new! I think the biggest lesson I learned with this is start at the source and work your way downstream with the fuel system! I would have saved a couple bucks and a bunch of time! It was a two minute fix it n the end!! Thank You All!
 

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