Regarding my tractor's possible issues with the injection pump!

[Arber]

Hi, everyone I am new here and have been having some issues with my Ford 3000 tractor.
Here goes>
The tractor refuses to start at 12v and basically cranks forever(there is no smoke while cranking or even an attempt to start) however at 24v(two 100AH batteries in series or 24v) it starts right up! Yet it doesn't smoke even when it first starts or when pulling things or even when punching the gas... it simply never smokes!
Now I have rebuilt the starter at a local starter machine shop thinking that is the issue but nothing really changed really it cranks the same like some videos I have watched on youtube so there is no problem there also compression should not be an issue since it works very well and pulls great once started and running but still doesn't smoke, it has a down exchaust pipe and the pipe is in good condition and not clogged.
My current suspicion is the injection pump which is a Lucas CAV DPA pump and it does have an issue where if you run it out of diesel bleeding it is a literal nightmare which does point out to the pump or rather the vane pump!
It has all new fuel filters as well as clean everything lines tank everything is spotless. Is there hope that I can fix the problem myself or just get the pump rebuilt and stop pulling my hair or could the problem be elsewhere!
Previously I have owned various Massey Fergusson tractors and none have had this problem!
Any suggestion feel free!

 

[Mike1955]

To me it sounds like low compression while spinning at a slightly lower rate of speed. Question is it spinning to slow; or is the compression actually lower than should be. I am not a ford mechanic but I would say that starting circuit needs a good hard look. Battery, starter and everything in between. That is the starting place since 24 volts starts it

 

[dodge man]

My thought was low compression also. It certainly could be the injection but it could be the injectors too. It could be lots of things, valves adjusted, broken rings, bad valve seat, the list is long.

 

[SiteEngineer]

Sounds like your starter and battery setup is fine if it runs on 24v. The fact it won’t start on 12v points to the injection pump not getting enough pressure to fire. Since you’ve checked fuel lines and filters, the pump is the main suspect. Rebuilding it could fix the issue, but you could also check the pump timing and make sure there’s no air trapped anywhere before spending money.

 

[Tx Jim]

It's a mystery to me when you attach two 12 volt batteries attached in series to attain 24 volts to tractor with 12 volt electrical system why the alternator & voltage regulator don't get "FRIED/TOASTED"!

I agree maybe engine has low compression causing no starting situation using 12 volts.

 

[Tinhack]

Start saving up a handful of $100 bills for an injector pump rebuild. And check the compression.