G1900s will crank but wont start

[CApatriot]

Hi Folks, hopefully someone can help me on this as I'm stumped.

I have a 1995 G1900s (4WS) with the D722e motor which I can get it to crank but not fire up.

I first had to replace the battery with a brand new 500 cranking Amp battery, cleaned terminals and gave it a crank and it would only turn over but not fire up. I checked that I did have diesel in the tank, made sure that my dash is lighting up and allowing time for the glowplugs to warm up (even going about 10seconds beyond the glow plug light going out) and still nothing.
I then checked and noticed that my kill switch solenoid was stuck closed so while waiting for a new solenoid, I went ahead and moved it out of the way (still connected at the pigtail but not depressing the kill arm on the pump. Cranked it again and still nothing.
Then I noticed that there was a bit of debris in the fuel filter so I went ahead and replaced both filters and to be sure I also drained the tank and got fresh diesel in it just incase there is water in the system. I bleed the system a the injector pump (by opening the little 10mm bleed screw) until it ran steady without bubbles/air. I then bleed each of the injector lines from the injector pump to the injectors (at the injector side not the pump side). I tried cranking/starting again and still the same.
I noticed that the stream when I cracked it at the injectors seemed a bit slow so I went ahead and replaced the fuel pump with a good aftermarket pump which seemed to do the same and again bleed the system and still it wouldn't start.
I then tested the glowplugs checking that there was actually power to the plugs and the little bar that connects all the glowplugs which looked good as it had a bit over 12V. I checked each glowplug (while still in the engine) with my ohm meter and got a 1.2 resistance for each plug. I tried starting it again and still the same it would only crank and not start.

I've went back and disconnected the pigtail at the kill switch trying to start it like that and it didn't make a difference. I reconnected it to the pigtail and then made sure that manually it would be in the open feed position and tried starting and still it would only crank.

I looked at the fuel lines seeing if there was a possible leak possibly and none was found. I checked the oil and the oil level didn't increase above the full mark nor did I smell any diesel in the oil from all the cranking and attempting to start the tractor. Interestingly I did notice that after a lot of cranking that when I took the oil cap off that I saw some vapour/steam come out. I was thinking maybe a blown headgasket or is it just the glow plugs trying to get the diesel started and the vapour is escaping past the valves?

I then thought maybe I have low compression although it sounds healthy and have no reason to think that it would be low. I have not tested it for compression as I don't have a diesel compression gauge and hope to avoid to do so as they are pricey.

I was also thinking that the injector pump might be bad? Not having taken one apart before is there really all that much to the pump that it could be the culprit?

Also, could the injectors be bad? but would all three go at once? I would think it would be a slow progression.

Well there's an earful. If you have any suggestions I'd be very appreciative as this thing really has me stumped.

 

[Dave_eng]

More historical info would help. Had it been running fine for months and suddenly a No start condition.

Has anything been disassembled or worked on. Valves adjusted for example...........

Dave

 

[CApatriot]

Hi Dave,
No it's been running fine about 6months ago. It has 650 hours on it and I bought it at around 500 hours.

The owner before didn't do anything to the motor to my knowledge. I haven't broken into it. I don't see any clear signs that someone has been in it.

I did see some chewed wires from what looks to be mice from sometime ago but it looks like it barely exposed some wires but it didn't chew through.

 

[BruceP]

You asked for suggestions... I would NOT be taking apart the injector pump. (It should only be opened up in a CLEAN envrionment)

However - you could test the injection-pump by loosening (barely crack open) the plumbing joints at the injectors and cranking the engine. Expect some fuel to squirt out all loosend fittings. This procedure also has the side-affect of 'bleeding' air from the lines into the injectors

 

[lugbolt]

is the fuel lever on or off? it is mechanical you can move it by hand. The shutoff solenoid pulls in and in turn pulls the lever on the governor to "off" which cuts fuel flow and stops the engine from running. If the lever it stuck closed (it happens) it won't run because it ain't getting no fuel

I know you said you disconnected the solenoid and tried it but that doesn't solve if the shutoff lever is stuck

secondly if you loosened the injector lines at the pump, there's a possibility that you've turned the delivery valve in the bore and ruined the pump. How did you hold the delivery valves from turning while you loosened the lines? Or did you ONLY loosen them at the injectors themselves?

if you loosened the lines at the injectors, did any fuel come out at all when cranking the engine? It'll only be a tiny bit if there is any. If none, you have an injector pump problem or a shutoff lever problem, something causing it not to get any fuel

by bleeding at the injection pump, the little 10mm hex bolt, that's all you need to bleed. Once that's clear, all you do is crank the engine til it starts. Simple, yet so many overcomplicate it because they see on internet and tv where somebody is loosening the lines, which is unnecessary on 99% of kubota's. Actually you don't really even have to bleed it at the pump's 10mm screw, if you have an electric lift pump (which you do). Just turn the key on, and go wash your hands or grab a cold coke. Give it about 5 minutes, it bleeds itself out with the electric pump. Done it many times on my own G1900S, as well as at work on a bunch of equipment (BX's come to mind).