M5700 fuel issues

[BBB123]

Tractor runs but not great. I’ve replaced the lifter pump put new filter housing on. Drained cleaned the tank several new fuel lines. Currently when I run I have the tank off so I can crack the injectors it looks like I’m getting air still. I don’t have a way to test pressure to the injectors but when I shoot the exhaust with infrared the front cylinder is 300 the rest are around 200 indicating the front one is firing. Is this just a bleed it more issue? My old does was that way. Or is the injector pump bad. Or are the injectors plugged or bad? Also. Before took tank off and did all this. If I ran it wide open for 4-5 minutes it would eventually almost stop running. Indicating it’s running out of fuel.
Any help is appreciated thanks in advance!!

 

[Captain13]

Sounds like you have an air leak where air is being sucked into the system when under load. Check any rubber lines and make sure they are old and starting to crack. Also, check any line fittings and make sure they are tight.

 

[Dave_eng]

Tractor runs but not great. I’ve replaced the lifter pump put new filter housing on. Drained cleaned the tank several new fuel lines. Currently when I run I have the tank off so I can crack the injectors it looks like I’m getting air still. I don’t have a way to test pressure to the injectors but when I shoot the exhaust with infrared the front cylinder is 300 the rest are around 200 indicating the front one is firing. Is this just a bleed it more issue? My old does was that way. Or is the injector pump bad. Or are the injectors plugged or bad? Also. Before took tank off and did all this. If I ran it wide open for 4-5 minutes it would eventually almost stop running. Indicating it’s running out of fuel.
Any help is appreciated thanks in advance!!

When owners suspect fuel issues they often rig up a small fuel supply directly to the injection pump intake port. A squeeze mustard bottle is one thing used.
The goal is to bypass any fuel system problems which informs you if the problem is in the fuel delivery system or injection pump/injectors.
Air can be sucked in where at the same location there is no external leak.

I dont hear you using the Hand pump mentioned in the WSM to accomplish bleeding.

Dave

 

[Tx Jim]

Many yrs ago I owned a M4900 that engine operated similar to what you describe. I finally located a tiny screen on fuel shut-off valve in water separator housing that was clogged. Cleaned screen & then engine operated fine

 

[BBB123]

Tractor runs but not great. I’ve replaced the lifter pump put new filter housing on. Drained cleaned the tank several new fuel lines. Currently when I run I have the tank off so I can crack the injectors it looks like I’m getting air still. I don’t have a way to test pressure to the injectors but when I shoot the exhaust with infrared the front cylinder is 300 the rest are around 200 indicating the front one is firing. Is this just a bleed it more issue? My old does was that way. Or is the injector pump bad. Or are the injectors plugged or bad? Also. Before took tank off and did all this. If I ran it wide open for 4-5 minutes it would eventually almost stop running. Indicating it’s running out of fuel.
Any help is appreciated thanks in advance!!

Tractor runs but not great. I’ve replaced the lifter pump put new filter housing on. Drained cleaned the tank several new fuel lines. Currently when I run I have the tank off so I can crack the injectors it looks like I’m getting air still. I don’t have a way to test pressure to the injectors but when I shoot the exhaust with infrared the front cylinder is 300 the rest are around 200 indicating the front one is firing. Is this just a bleed it more issue? My old does was that way. Or is the injector pump bad. Or are the injectors plugged or bad? Also. Before took tank off and did all this. If I ran it wide open for 4-5 minutes it would eventually almost stop running. Indicating it’s running out of fuel.
Any help is appreciated thanks in advance!!

When owners suspect fuel issues they often rig up a small fuel supply directly to the injection pump intake port. A squeeze mustard bottle is one thing used.
The goal is to bypass any fuel system problems which informs you if the problem is in the fuel delivery system or injection pump/injectors.
Air can be sucked in where at the same location there is no external leak.

I dont hear you using the Hand pump mentioned in the WSM to accomplish bleeding.
View attachment 108349
Dave

The hand pump method hasn’t been tried. Everything is bled to pump lines are new I even replaced the water separator the old one wouldn’t shut off. I’ll try that.

 

[BBB123]

After exhausting everything else I finally had the fuel injector pump rebuild and that solved my problems.