New BAD habit on the 1772
 

This past weekend, the 1772 started with a new habit. It seems to be fuel related. When I am starting it, the engine turns over and fires as it should. However within the first few seconds after it starts and I release the key switch from the starter position, the engine begins to misfire drop in rpm and stop. I initially thought I thought the throttle was set too low in speed, so I increased it to 1/2 way. Tried again, the engine reacted the same way. OK, I pushed the throttle to 3/4 and tried again, same results - 2 times. Now, I tried it again at full throttle, sort of the same, ran rough for a few seconds then straightened out. I was able to mow the lawn without a problem. After I finished mowing, I shut it down to clean off the deck. When done it restarted with the same difficulty I was initially having.
I threw new filters and a new fuel pump at it. Same story...... What's left? How does a bad injection pump react?

If it's not fuel I would see if the coil is grounding out through a bad wire/connection some where

This is the Kubota diesel, not a gas, unless you mean somethin besides the ignition coil

ooops, nope - that's what I meant-sorry

sounds like air in the system, did you bleed everything in proper procedure after you replaced the pump?
Got an old perkins 6-354 that likes to pick up air after sitting a spell.
:bigthink:

Yes, I did bleed it, but you know sometimes a pocket of air can find a good spot to hide. I'll bleed it again and see if it starts better. Thanks, George.

It sounds like you had the problem to start with.
try cracking the lines one @ a time right @ the injectors to maybe bleed off any air.
Hopefully it is that simple, but maybe J. Mech will have some suggestions or others that have more experience with those jay-pan 'injins
Have heard of rebuilding pumps and injectors on those, but not the norm. :bigthink:

Hopefully I can get to it tonight. I did not want to do any of this in the pouring rain last night.

Is the fuel pump running when the key in the run positon

Yes it is, but I swapped it out anyway.

How old are the fuel filters? The 1782 I had did the same thing, new filters problem solved.

The filters are about 9 months old.

I FINALLY got time to work on the 1772 today. At first when I tried to bleed the fuel system out, but nothing came out. So I turned it around so the nose was a little lower than the rear of the tractor and I tried again. It was spitting out air this time. I don't know if it is supposed to be perfectly level or at an upward or downward slant, but when the nose was lower, I was able to get some air out of the line. It started up a better and I will see how it goes. In any case I drove it around to my garage and thought I would check the air gap on the clutch.

Have you replaced the fuel lines from tank to injection pump?

Could be air, but not air that got left in the system. If you got it to run, then it acted up again, it's not a "pocket" of air. When a diesel finally runs well, the air is purged from the system. It can't "hide". Only way for it to get air again is if it's introduced, via a leak, or opening the system.

It's not the injection pump. My bet is either a hole in a fuel line sucking air, restriction on either fuel supply, or return, or a faulty fuel supply pump. Everyone always overlooks the fuel return on a diesel. It's a critical as the supply. A plugged return line will cause the internals of the pump to hydro-lock and stop pumping fuel. Seen that a million times.

Did you replace the fuel pump with one made specifically for diesel? It does matter. A gasoline electric pump will not last with diesel fuel.

Not sure I'm understanding the downward slant thing. If you mean you need gravity to help the fuel come out of the line then something's definitely wrong. When I would purge the lines on my diesel per the manual it would shoot fuel out because of the pump.

Fuel came out both time, but it wasn't until I had the nose pointed downward that I started to get air out of the system. I figured on the first time, while fuel came out, maybe the air was trapped in a pocket or something.

The fuel lines have been replaced not my me but the the PO. I did replace the supply pump with a new one from cub cadet - pricey little devil!

BTW - what's the difference between the (PRICEY) cub cadet fuel pumps and the ones you see on evilbay for $25.99 ? Are those gas models that are being used for diesel or some sort of cheap knock-offs.

Could you post a picture of the fuel pump you used?

Frank

I'll just toss out everything I would do if it hasn't already been done.
1: Pull the tank, clean it out, clean or replace the fuel shutoff.
2: New fuel lines both supply and return.
3: Fuel filters
4: Electric fuel pump (you said you replaced it)

I recall someone else a while ago with a Diesel with similar issues check the Kubota section in the engine area.

Finally some time tonight. Here's a picture of the fuel pump.

Attachment 68113

According to the numbers on it..... it is the correct fuel pump, from Kubota. Unless it's just junk, or not getting power, it should work fine.


I'd still flush the tank and run new lines.


Has it given you any trouble since you got it running the other day? :bigthink:

Jonathan, I started it up last night to replace a wearing tie rod end joint on it, and it started up without a problem. Turned right over and was running right off the bat with no problems. I just can't figure out what happened and where the air came from. I mean it's been running fine for about 9 months since the fuel filters were changed on it, then all of a sudden WHAM! This came out of the blue. Just another gremlin that I hope has moved on.