Calling All Diesel Techs (Update)

You may have seen the  previous threads of mine about trying to get a 3cyl. diesel Kubota B7100 running. Well, it still won't run. The injection pump was looked over by an expert and found nothing wrong. The injectors were tested and were good. Clean fuel flowing through all lines. Glow plugs are good. It will not start on ether or brake cleaner. The engine seems to have good compression as I have held the palm of my hand over the intake manifold while cranking and it sucks my palm in. I haven't checked the compression officially as I don't think that's the issue. The pump shutoff is purely mechanical, so I know when it's on or off. What am I missing here guys?

-Slim


Edited by Slim - 22 Nov 2016 at 4:38pm

I have a small yanmar loader tractor with a 2 cylinder diesel. If you run it out of fuel no amount of pulling or ether will get it running. There is a small bleeder screw on the fuel pump or filter head can't remember which. Bleed that and it starts right up. Yours probably has something similar.

Those PFR systems are very tough to get bled. Leave the lines loose at the injector ends, and keep bleeding until you get fuel there. Might help to bleed to the pump first. They pump so little fuel, it's really hard to get the air out. 

What's the back story? Did you buy it this way? Or did she up and die when running?

not getting enough fuel.... Don't use Ether, use a little WD-40....

COMPRESSION!!!!!!!!!!! Is first thing you should have checked after seeing that it pumped fuel. If its not above 350#'s it won't run-start. 395 to 450 is normal. Also all glow plugs need to work! As other said pull it and see what happens. But I bet it doesn't have enough compression! Not hard to bleed! Bleed first at hose-fitting going into pump, and crack a line on injector. We sold hundreds of them and were a Great Tractor. But like any engine some get neglected! And they do wear out!

Sounds like you demonstrated that it has vacuum. Doesn't tell you that it has decent compression. Should start by pulling it, though....

Pull it fast enough to spin the engine 1500 RPM or so and it should eventually start. Once running, then if you continue to have starting issues, run a compression test on it.

Glow plugs are good. Just checked compression and it is around 150 which is crap. Looks like a rebuild.

-Slim

I jus has a lady call me and say her lawnmower will not start. I went over and looked at it would crank slow and try to start. I tried ether still nothing. After a couple more times the starter was hot to the touch. I got a new starter and installed it turned over a lot faster and started on second try. I have had trouble on some JDs that did not start also and same problem engine was not cranking fast enough to start. But some engines will start even if cranking slow some will not.

If the pump has been off, I would check your timing. May be 180 degrees off. Regardless, verify timing. Also may have a head gasket issue.

Also, in cold weather, starting some of these little diesels can be a real pain.  Especially if you don't have a 'lectric preheater, on 'em.  I have a trick for that, too.  Take a single burner coleman gas stove, or radiant tent heater, and slide it under the oil pan, and let it warm up for about 45 minutes.  Don't do it on a oil leaking motor, though, LOL...

AC720Man wrote: Thanks for correcting me Ed. I guess all Orange tractors are not the same lol. I shouldn't have chimed in on a brand that I know nothing about. Plus being newer as well. Sometimes I just can't help myself.