3910 not starting

[NHbalerman]

I have done a lot of work to this tractor and the other day it just started running rough and smoking like a freight train the number 3 cylinder is the bad one so I put another injector used that was on the shelf no help so I pulled the head to see if anything on the inside was bad but nothing so now trying to crank it and all it does is smoke gray smoke like before but I could finally get it cranked of course bled the injectors do y'all think this is a injector problem? Had the pump rebuilt new gas tank. Any advice is welcome
Thank you

 

[Destroked 450]

Generally heavy smoke is a air intake issue but anything is possible
It’s always best if a injector is suspected to be bad to swap it with one from another cylinder, if the issue moves with the injector then it is most likely the issue
I did basically the same thing you did on a 4 cylinder model, number 3 cylinder had a knock, I swapped in another injector I had and the knock was still there
Pulled the head and all looked ok, dropped the pan to remove the piston and rod, again all looked ok
Turned out the injector I had swapped in was also bad, lot of work for nothing

I have experienced the past couple of years that even though I’ve had good filter and fine black film has developed on the screen inside the fuel regulator on the back of the injection pump
A way to check is to make sure you have good fuel flow to the pump inlet, remove the bleed screw on the side of the pump and crank the engine over, fuel should squirt out with force at least a foot or more, if it dribbles out or has a weak stream the screen needs cleaned

 

[NHbalerman]

Thanks for that info I haven't checked the air filter in a while then I may try swapping out the injectors the one I put in there may not be any good either. Just one of those things that will make you pull your hair out

 

[Destroked 450]

Don’t have much left to pull

 

[Texasmark]

Generally heavy smoke is a air intake issue but anything is possible
It’s always best if a injector is suspected to be bad to swap it with one from another cylinder, if the issue moves with the injector then it is most likely the issue
I did basically the same thing you did on a 4 cylinder model, number 3 cylinder had a knock, I swapped in another injector I had and the knock was still there
Pulled the head and all looked ok, dropped the pan to remove the piston and rod, again all looked ok
Turned out the injector I had swapped in was also bad, lot of work for nothing

I have experienced the past couple of years that even though I’ve had good filter and fine black film has developed on the screen inside the fuel regulator on the back of the injection pump
A way to check is to make sure you have good fuel flow to the pump inlet, remove the bleed screw on the side of the pump and crank the engine over, fuel should squirt out with force at least a foot or more, if it dribbles out or has a weak stream the screen needs cleaned
View attachment 70038View attachment 70039

Thank you sir. I have 3 Fords with CAV pumps and don't currently have a problem but knowing of that screen and where it is, is good to know.

 

[Texasmark]

Thanks for that info I haven't checked the air filter in a while then I may try swapping out the injectors the one I put in there may not be any good either. Just one of those things that will make you pull your hair out

When I crack the fuel line input nut and get a positive degradation in the engine performance I figure the injector is doing its job. If I didn't or got a slight response and the engine was not running up to par then I would expect a bad injector.

 

[NHbalerman]

Well I ordered 3 injectors this morning I will let y'all know what happens