I've got a Kubota B7500 I'm fixing for a friend that I'm thinking may but probably won't be the fuel pump. Wild shot in the dark here, but would anybody know what the fuel pump pressure should be on that tractor?


The problem that it's got is that it loses power pretty fast when you put it under load, and then seems like it isn't getting enough fuel and will eventually not rev up past idle. I've ran it in the shop at full speed without putting it under load for 15 minutes and it never missed a beat. I took it out and shredded with it and it wasn't running well in under a minute. I'm getting good flow out of the tank, new fuel filter, new air filter, great flow to the fuel pump. I've pulled the hose from the pressure side of the fuel pump while it's running poorly and seem to get a good pressure/spray, but would like to check pressure. I pulled off an injector and verified that all hoses and lines were free of blockage and sealed up good. the injector was clean as could be. The fuel cap is venting.

I'm putting it all back together now to do more testing, but thought somebody might have some insight as to where to look next. I've always found diesel tractors to be overly easy...but this one's getting the better of me.

Anybody?

I've put it all back together and started it up. Now it loses power much easier. I've been looking for possible air leaks. I guess I call Normangee Tractor to see if they can tell me fuel pump specs.

Don't know the numbers for you. Sounds like you're doing the right things.

Is there only one fuel filter? Most JDs have at least 2.

I have seen a similar thing in my combine. It was debris in the fuel tank. I would have to pull the sediment bowl out from under the tank and clean it. Sometimes stopping the engine for a minute or two to let the crud float away from the intake would help.

Ddp

[This message has been edited by CanyonAg77 (edited 6/18/2008 11:38a).]

www.tractorbynet.com

Im assuming this is a diesel engine?

It most likely only has one fuel filter. Most newer tractors only have one GOOD filter, its not necessary to have more than that.

Does it smoke? Is there any way your timing is off somehow?

[This message has been edited by jed1154 (edited 6/18/2008 12:35p).]

It's a diesel. Yes, there's only one fuel filter and it's new/flowing well. No smoke. There's no way the timing's off. Nobody's messed with anything at all on it before. It's only got 110 hours on it.

I'm supposed to call a guy back at Normangee tractor...he's going to give me the specs on the fuel pump. I feel I need to check it even though I still feel like it's an air leak I can't find or something like that.

I dont know much about diesel engines, but an air leak would seem like a place to start, maybe a gasket.

Had a problem with our Kubota running like crap. Turns out when we replaced the air filter, the new one was not right, and really screwed things up. Ran it without the center element until we could get a different one. Probably not your problem though...

quote:

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Most newer tractors only have one GOOD filter, its not necessary to have more than that.

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That explains it, mine is a 1994 model.



Older (1973-1990 or so) JDs had an inline filter, then two glass filters. My 1994 has an inline plus one metal filter that fits the same base as the old glass ones.

yeah, my older MF240 has two filters. My '04 Case only has the one.

Did you check the pressure in the higher rpm's when you put a load on it?

Well, I've been on and off of this tractor seems like all week wasting time. I just figured it out....It's got one bad injector. I'll have a new one early next week. I hope that fixes all the problems and I didn't cause another problem trying to find this one.

Resurrecting this old thread because I have an old Ford 1600 that appears to be running on only one cylinder, and I suspect an injector or injector pump issue. I'm going to drop the glow plugs this weekend and see if it is jetting fuel from both injectors. (It has a 2 cylinder shibaura diesel).

Is it typically pretty easy to clean injectors or injector pumps on these little diesels? I can't tell which cylinder is firing and which is not without pulling the plugs. I had a water in the block issue with this tractor after Ike blew a bunch of rain up into the air cleaner mushroom vent and it got into the heads. I managed to blow that out by removing the glow plugs, but the couple of times I tried to turn it over before I realized it had water in it, I hope I didn't do more damage, and the cylinder not firing is because of a fuel feed issue. It could also maybe be a fuel line leak.

If I remove the fuel lines to the injectors, do I have to "reprime" them with fuel to get the injector pumps to work?