Saving A Ford 3910

[Birdhunter1]

I would like to know how the compression is in each cylinder, but with the pump off wouldn't I throw the timing off if I turned the engine over?

I wouldn't crank the engine until you have the pump back on, I think in the service manual it says not to as a gear can jump out of place and your timing is set now so why mess with it to have to time it again.

 

[PM Wells]

Thanks for the advice, I am going to wait until I have the pump back in place and with some fuel in the pump before I turn the engine over. I don't want to take a chance on the timing getting off, if that can happen on these engines. I am hoping that with the rebuilt pump, and injectors, and compression check will take care of the engine problem. Then I can move on to other maintenance issues.

 

[Birdhunter1]

You can crank it by hand for your compresion test without fuel in the pump, a socket on the harmonic ballancer will do it.
Or just crank it with the starter enough to do your test, shouldn't hurt a thing.

 

[PM Wells]

I had the injectors checked today, all three are in about the same condition, some fuel getting through, but not in a mist. I will be getting rebuilt injectors from D&C Diesel along with the rebuilt pump in a few days. So it looks like the Ford 3910 was in need of some new injectors along with the pump needing some work on the metering valve and a good cleanup.

 

[RickB]

You can crank it by hand for your compresion test without fuel in the pump, a socket on the harmonic ballancer will do it.
Or just crank it with the starter enough to do your test, shouldn't hurt a thing.

A compression test requires cranking speed of +- 200 rpm. That’s a little beyond hand cranking.

 

[PM Wells]

I was told that a leak down test can tell about as much about the condition of the engine as a compression test, and that I could use an old injector with the nozzle tip cut off and with an adapter for air and gages, and could be done without turning the engine over.

 

[RickB]

It will.

 

[PM Wells]

Still waiting on my injection pump to get back to me, so I can get this tractor going.

 

[ovrszd]

Good luck with this project. Look forward to seeing it complete.

 

[PM Wells]

I appreciate that, I read your post on your injection pump problem you had a couple years back, and learned a lot from that. Thanks for posting that.

 

[ovrszd]

No worries. Document everything you can in this fix so a reader in the future will say the same thing to you about this thread!!

 

[ovrszd]

I tried removing my injectors and gave up. I've gotta pull my head and take it to someone that can get them out.

 

[PM Wells]

Does your injectors have studs with nuts to hold them down, or do you have bolts that you can take out? Reason I am asking, mine have bolts, and I was able to take a flat punch about 1/4 in thick and tap on the flange of the injectors back and forth until I saw some slight movement, once you get them to turn you can take a small pry bar to get them to come up.

 

[ovrszd]

Mine have bolts. I'll try that this Winter. Thanks for the tip!!

 

[PM Wells]

I found that dirt and moisture can get down in the hole around the injector even though there is a cork seal. You may try some light weight oil down around the injector to help free it up.

 

[ovrszd]

Thanks again for your help. I'll let you know how it turns out.

 

[thepumpguysc]

THOSE injectors are just about the worst to have to pull.. other than that JD w/ a Yanmar engine that I had to buy the tool from Hoye, to remove.
Theres usually a "flat spot" right before the top nut that u can use a Cresent Wrench to grab & turn.. therefore breaking the rust bond..
Soaking them down is a GREAT option..
What u DONT want to do is> grab it by the TOP nut.. THATS the pressure adjuster..
Good luck..

 

[PM Wells]

I should have the rebuilt injection pump back shortly, along with three rebuilt injectors. Apparently before I got this tractor someone had been into the pump and left something out of it according to the Man who rebuilt it. Should be good now. He is letting me use a modified injector with compression gauge, so I can check the compression before I install the new injectors. Hoping it will be good and we can fire up this 3910 and see what we have.

 

[shovelmike]

Hi there, fellow Missourian! I wish you the best of luck with the Ford 3910.

 

[PM Wells]

Thank you, I am new here too, and having a good time reading over all the forums. I am from North Carolina, I was in Missouri a few years back, great state.