Experiencing Intermittent Shut-down

[TemporaryKubotaOwnerMark]

I agree with Andy. I'm fighting a similar problem. Maddening!

 

[TnAndy]

Many years back, I was a turbine engine mechanic in the Army. We had a Huey that was bad about "hot starting"......where a big ball of flame rolls out the engine exhaust and scorches the tail boom paint among other things.

Warrant officer whose bird it was came storming in the shop one day "CHANGE THE &%%$# FUEL CONTROL AND GET IT STOPPED".

Well these engines have a 'start fuel' circuit and a 'main fuel' circuit. Start fuel dumps a little in thru 4 nozzles to 'kindle the fire' before the main fuel comes in thru a ring of nozzles. No start fuel (about 10 seconds) and the main fuel dumps a bunch of fuel into a cold chamber....when the pilot hits the ignition button....FLOOOOOMMMM....out goes a fireball ! ...hence the condition "hot start"....which has to be logged in the bird's book every time.


I got to checking, and found Bell had simply never run the wire for start fuel !...put a meter on the cannon plug, nothing. So I wired it up, got start fuel to working, and saved the taxpayers about $25k that a new fuel control (kinda like injector pump on a diesel) would have cost.

 

[CalG]

Many years back, I was a turbine engine mechanic in the Army. We had a Huey that was bad about "hot starting"......where a big ball of flame rolls out the engine exhaust and scorches the tail boom paint among other things.

Warrant officer whose bird it was came storming in the shop one day "CHANGE THE &%%$# FUEL CONTROL AND GET IT STOPPED".

Well these engines have a 'start fuel' circuit and a 'main fuel' circuit. Start fuel dumps a little in thru 4 nozzles to 'kindle the fire' before the main fuel comes in thru a ring of nozzles. No start fuel (about 10 seconds) and the main fuel dumps a bunch of fuel into a cold chamber....when the pilot hits the ignition button....FLOOOOOMMMM....out goes a fireball ! ...hence the condition "hot start"....which has to be logged in the bird's book every time.


I got to checking, and found Bell had simply never run the wire for start fuel !...put a meter on the cannon plug, nothing. So I wired it up, got start fuel to working, and saved the taxpayers about $25k that a new fuel control (kinda like injector pump on a diesel) would have cost.

Based on that experience, Check the fuel cut off control unit. Not the solenoid it's self.

Hot starts for ant reason suck on any turbine, And yes, I have my A&P certificate. ;-)

 

[k0ua]

Nope.....I specifically said: "as soon as the tractor dies, LEAVE THE KEY ON, and you should hear the pump. Now pull a hose off forward of the pump and see if you're getting good fuel flow."

IF you have a tank outlet tank obstruction, such as I had with the 'bug-in-the-tank', leaving the key ON when it dies keeps that pump running.....pulling a hose off at that point, you'll see just a dribble of fuel. The vacuum pull by the pump trying to get fuel will keep whatever is in the tank RIGHT OVER THE FUEL OUTLET. In my case, I could actually see the sides of the plastic fuel filter bowl sucking inward also as that pump tried to get fuel.

What happens, I suspect, if you turn the key off, then on again and the tractor starts is enough fuel has dribbled out and made it's way forward to the injector pump to let the tractor start again. You throw it in gear then, and whatever is in the tank floats off the fuel outlet UNTIL THE NEXT TIME IT FLOAT BACK AROUND OVER IT AND YOU STOP AGAIN.

Your description:

" could barely hear the 'tick-tick-tick'. It was there, but almost a "chitter" and very faint. The engine started again (thank goodness I've got a great battery & starter!) and took the almost standard 5 to 6 seconds to fire up = back to work."

is exactly what happens.....the pump sounds different because of blocked flow, it takes it 5-6 seconds to build up enough fuel for the injector pump to HAVE something to pump, then engine starts....jiggling whatever is floating around in the tank to float away to come back later.

The dealer thought fuel solenoid on mine too...changed it TWICE....before it managed to die while sitting in their shop (after I'd taken it back home, 'fixed' and returned it the same day) When it died, we're standing in the back looking at it, the mechanic says "man....look at that fuel bowl" (which is located under the left rear fender inboard of the tire)....it was bowing inward as the booster pump tried to suck fuel.

He immediately pulled the hose off the tank bottom going to the fuel bowl, and just a dribble of fuel came out. He stuck a long, skinny screwdriver up the tank outlet and got hosed with fuel as whatever it was ( a bug, wrapped in some plastic, spiral drill shavings from drilling the tank FOR the outlet fitting) moved aside and fuel RAN. Removed the tank and dumped it upside down thru a cloth, and caught the problem.

The NEXT time it happened, about 2 years later, I knew what to look for. Rather than remove the tank, I bought a cheap, lighted inspection camera with a 3' extension (Rigid Brand, Home Depot), and LOOKED IN THE TANK for myself....yep....there floated a dirt daubber wasp right over the outlet. Reached in with a long 'grabber' kinda tongs, pulled it out, and no more problem.


Now this may, or may not, be your issue......But I wouldn't go one step farther until I was dead sure I had good fuel flow.....and I've told you how to determine that.

Having had this happen to me twice now on the same tractor, once at 50-60hrs, then two years later, PLUS my experience with that Mitsubishi dozer, I'm inclined to look for the simple stuff FIRST.

>FUEL FLOW<

Until you are 100% positive you have proper flow, don't go looking for other trouble spots and trying to over think the problem.


Merry Christmas, by the way, down under !

This seems like very good solid advice to me.!

 

[Wagtail]

Thanks Mates for all of your advice.

Right now it's too wet to carry on haying so my tractor is sitting in the paddock. It may be the new year 'til we can get back at it.

I'll keep you advised. Ta and Happy New Year.

 

[Wagtail]

Well, it's the new year and the 4105 is back in my shed after a bumper hay crop.

Firstly, TnAndy, thank you for your advice. The fuel bowl on my rig is too ridged for it to bow... but I did discover a semi-fault with it, which I'll come to. Suffice it to say that the shut-down fault is heat-over-operating-time. Every morning without fail the tractor would/will start and run perfectly normal. Only after 1/2 to a full hour of operation would the first shut-down occur. The diesel engine would "die" from lack of fuel as opposed to the quick shut-down you get when you turn it off.

I purchased a new fuel solenoid over the holidays and attempted to fit it. CRICKEY! How jammed in/inaccessible do these engineers position these parts! There are only two bolts holding the solenoid in but I could only get at one of them... after pulling some pretty impressive yoga contortions and de-greasing one half of tractor onto my clothes. The other bolt was impossible for me to access; I simply lacked the correct 10mm extension to reach it or shifter to fit in the allotted space.

In order to reach the one bolt that I could, I drained and removed the fuel bowl. Draining the bowl took longer than it should have; I even unscrewed the entire drain-cock off and had to tap the bowl before the diesel started to pour. Short story is that there was a fair bit of oily 'greenish-brown' sludge at the bottom of the bowl and on the screen. It wasn't covering the entire screen... sort of blotchy. I cleaned it all out and, after giving up on getting the solenoid out, put every thing back together. I observed the bowl as the system re-primed itself and fuel flowed freely into it.

I then hopped onto TBN and read up on Biocide diesel fuel additives = into my town to purchase some & treat the tank and my fuel. Yes, I know I'll need to replace the fuel filter a few times in the very near future.

Yesterday I drove a visiting friend to the airport and took the opportunity to swing by my dealership on my way home. Not only was there a mechanic available to talk to (and access the JD Mechanic's Website) but they had a 4105 sitting in the showroom! Lots of information exchanged + a wiring circuit diagram printed off and traced... which led to a simple plug-in fuel system relay! I bought one (A$20).

When I got home I had a visit from my next door neighbour who'd been fishing and wanted to share some of his catch... he's also a good back-yard mechanic. I ran the tractor over to his place today and he had the right tools to get at and change the solenoid! The tractor, of course, runs great... but it always does until it's been worked for a while. In thanks for his help I'll load up the slasher (bush hog) and clean up an area of his property next week to test the tractor out.

 

[TnAndy]

I purchased a new fuel solenoid over the holidays .....

Yep...the dealer replaced mine twice before it became sort of obvious the odds of 3 (original + 2 ) of them being bad was astronomically low......

 

[Wagtail]

Yet another update and I'm not too proud to admit mistakes, especially to TnAndy... but part of posting is for knowledge/experiences to be shared.

Simply put, changing the solenoid & relay didn't solve the shut-downs. In a way, they got worse but I reckon that that's because I added the biocide = the dead crap has to go somewhere, right?

Yesterday I got about 3/4hr of work out of the tractor before it flat-out shut down and wouldn't re-start (first time for that happening). I decided to drain the tank (1/2 full) and only a bare trickle came out. I put everything back together, waited an hour (of course the tractor fired back up again as if nothing was wrong) and got it back to the shed.

I've got an inspection camera on order to have a good look at what's blocking the tank... fear that I'm going to have to remove the tank and huck it out.

 

[k0ua]

Yet another update and I'm not too proud to admit mistakes, especially to TnAndy... but part of posting is for knowledge/experiences to be shared.

Simply put, changing the solenoid & relay didn't solve the shut-downs. In a way, they got worse but I reckon that that's because I added the biocide = the dead crap has to go somewhere, right?

Yesterday I got about 3/4hr of work out of the tractor before it flat-out shut down and wouldn't re-start (first time for that happening). I decided to drain the tank (1/2 full) and only a bare trickle came out. I put everything back together, waited an hour (of course the tractor fired back up again as if nothing was wrong) and got it back to the shed.

I've got an inspection camera on order to have a good look at what's blocking the tank... fear that I'm going to have to remove the tank and huck it out.

I think you got something growing in there...We used to have an old troubleshooting saying: "do that thing you don't want to do first"...And you know what that thing for you is... Drain that **** tank and clean it out.

 

[TnAndy]

Next time it happens, and you have the fuel hose off to the tank and see just a dribble of fuel, stick a skinny, long screw driver (or something like that) up in the fuel outlet....see if you can 'bump' whatever is blocking flow out of the way....you should get hosed with fuel.

Once you have an inspection camera, pick up a set of long 'grabber' tongs (like these: Mechanical Pick-Up | Canadian Tire ), and if you're lucky, it's something solid (like a bug) you can grab and not have to take the tank off and clean it.

But if it's sludge, tank is gonna have to come off.