Mitsubishi S4L2 (4 cylinder) in a Terex TC37 won't prime

[Sedgehammer]

I know this is frustrating.. so either call the rental co. & face a fee or start from the beginning..
Seeing its a rental.. u have no idea what its been thru & how other people treated the fuel system..
Start from the beginning.. take the line off at the tank & check the flow.. not just for a second but for about 10 seconds..
LET'R FLOW..
Now put the line back on & do the same ALL THE WAY to the inj. pump INLET.. & you'll prob. find the problem IF its fuel related.
Does this machine have an electric shut off?? {shuts off w/ the key}
U could take it off.?? & eliminate any electrical safety switches that are shutting off the inj. pump..

Actually used the electric fuel pump to empty the tank. Flow is good. Plus ran a gallon through before originally hooking fuel line back up to start with. Plus bled the bleeder valve under pressure while cranking it. No air is vented. Just fuel.

Filter is located right next to fuel pump at the bottom of the tank.

On the electric shut-off switch, how does one do that?

Why doesn't it fire on either ether or wd40?

Is it possible that it never ran out of fuel since we put 9.75 gallons to fill it when this all started and the tank is 15 gallon tank, so it's injection pump related?

What about blowing air in fuel tank while trying to start it? If so, do with or without injectors cracked?

Thanks

 

[Sedgehammer]

Update. I think my prior suspicions are correct. It never ran out of fuel. It starts and runs as fine as a 4 cylinder can run on 3 cylinders. Have to leave 1 line spitting fuel/air out to keep it running. As soon as that line is tightened back up, she dies. Ran it for 45 minutes. It appears though that there are air bubbles, as it kinda foams at the injector, but there is something else causing this I'm thinking.

 

[thepumpguysc]

Its very possible & highly probable that the injector on that 1 cylinder u have to keep loose, is stuck OPEN & is force feeding compression back into the system/inj. pump.. hence the air bubbles & no start..
Take the suspect injector out & get it/them tested or just swap it to another cylinder & see if the problem follows the injector..
Good Luck.

 

[CobraTom]

Update. I think my prior suspicions are correct. It never ran out of fuel. It starts and runs as fine as a 4 cylinder can run on 3 cylinders. Have to leave 1 line spitting fuel/air out to keep it running. As soon as that line is tightened back up, she dies. Ran it for 45 minutes. It appears though that there are air bubbles, as it kinda foams at the injector, but there is something else causing this I'm thinking.

If it is foaming at the injector the injector line is not tight or the injector body was loosened when you were bleeding. If it is spitting fuel/air out, sounds like you have the injector half apart.

Can you take a photo of the suspect injector/cylinder This engine comes in both direct and indirect injector versions and both are very different injectors.