lost prime 2 times today. while running mowing

[SPIKER]

Hey all:

m 600hr Jinma lost prime 2 times today, not sure what is up I changed fuel filter last fall and oil as well all are good. fuel level over half full with pump fuel ULSD with additive to bring back some of the needed lubricants. I was mowing for maybe 30 min when it stopped the first time, & would not fire. It slowed and stopped pretty quickly all fluids seem up to par, pumped up but leaked a lot of fuel from plunger of bleed pump. It fired & stumbled abit cleared up and ran fine for 150 yards of mowing and died slowly again. I again bled the air out and primed it with hand pump & could hear air in system pushing back into tank and thru past the bleed screw on injector pump. I didnt have to crack any lines but I will check lube in the injector pump tomorrow.

Going to also drain the bowl and make sure to check out the screens, I DO still have the screen in the tank fill hole so all fuel is filtered thru that & pretty clean going in. bowl is clear other than decade of buildup of outside dirt on it.

Can the pump suck air in around the leaky hand pump>?

In the time I have owned it only ever had to use primer pump 2 times for changing filters so not taken it apart but dont remember it leaking fuel out around when pumping as bad then.


mark

 

[Bob Rooks]

The guys I know of have yanked that in-tank screen out and discarded it. It serves no practical purpose if you can't get to it to clean around it. There is a very fine screen in the top of the sediment bowl, but maybe you already know that. :laughing:
The lift pump has two check valves - the one on the inlet side could have debris in it holding it open, and thus no fuel pressure. If you have compressed air handy, disconnect the inlet line at the lift pump and gently blow back into the tank. Remove the fill cap first. If you find any traces of brown or black slime, welcome to the "Bug Club".

 

[greg_g]

Can the pump suck air in around the leaky hand pump>?

Yes. All that seals it is a single rubber O-ring. ULSD is hard on rubber, hence the introduction of Viton rubber seals and hoses for fuel systems running ULSD. You can remove the hand pump and try to replace the O-ring, but that style is cheap and readily available in most big diesel parts stores (the ones that sell parts for the big over-the road diesels and large farm tractors). They're not at all expensive, and you might be better off simply replacing your OE hand pump. In addition, any of the rubber hoses on the low pressure side of your fuel system could be decomposing from the inside out. At 600 hours, it's probably a good idea to replace them with Viton tubing as well.

//greg//

 

[SPIKER]

thanks guys, will be looking into it today if I can get moving... burnt winter brush and tree trimming piles yesterday & had 15 or so BIG piles to move & burn so wore out...

Mark

 

[Bob Rooks]

One of the O-rings that Greg mentioned (there are two) is on the piston rod that connects to the cam roller. It is supposed to prevent cross contamination of the injection pump oil with fuel. The other is on the hand plunger shaft. The hand plunger assemblies used to be available separately for around $10. Check with Tommy. I found it necessary to replace my whole lift pump assembly due to corrosive bug damage. They were about $35 at the time. One thing to check before you order a lift pump is if the hand plunger is on the left or right side, facing the pump.

 

[SPIKER]

Hi Guys:

I tore into it this afternoon and 3.5 hrs later I figured it out.

I pulled fuel bowl which was clear of water and dirt.

I pulled hose off at the banjo fitting and opened valve up and flowed a solid 1/8" or so stream of fuel.

I pulled the fuel filter (it only has 20 or so hours run time) and confirmed it was less than half full, (Sucking Air I assumed) so pulled off all the banjo fittings. Checked all of them for cracked copper sealing washers (all seemed good.)

Next I pulled off the primer pump and cleaned it and put in new O-Ring on the base seal of that & disassembled it and cleaned & used some grease in behind/on top of plunger rod & piston wrist pin area to seal any small air leaks. Put it back on, pulled fuel filter 2nd time and filled it with fuel and re-primed and cranked it over. It started sputtering bad 1 cylinder firing at most 500 RPM out of it. After a few min it cleared up a bit but was missing for sure.

Moved it about 5 feet and it died out of fuel again. looked at fuel gauge yep 3/8 tank on elec gauge. argh

by this time I have been tinkering for 3 + hrs... re-filled the filter and re-primed system used some carb cleaner to wet ALL of the banjo fittings and the fuel bowl etc & cranked it over till it fired, spitting & sputtering I got off and kept spraying one at a time & finally it cleared up some. SO MUST be one of the fittings I was spraying, so stopped spraying 1/2 of them and yep it slowed & died. Hummm so pull fuel filter and re-filled and re=primed it to start process over. Used some grease on the ones where I figured it must be. Fired it up and drove it out around the barn & made it to the back side where it sputtered & began to stop...

I managed to get it almost back to the front of the barn and it stopped yet again...

OK well it was under the shade tree & happened to be a branch hanging down that I snapped off with my hand & stuck it down into fuel tank just because it was last thing to check (remember looking at fuel gauge which has always worked accurately says 3/8 tank.)
Well pulled stick out and it was dry except for maybe 1/4" of the bottom... sigh

well filled it up & primed the system it ran like a top dumped a lot of time work and effort into a stupid gauge not working well... Going to have to clean top of tank and gauge to make sure it is not shorting some driving gauge up and see fi it fixes it. Well EPIC work for silly issue but sure others have done something similar...

Mark

 

[Bob Rooks]

So how does it feel to know that you are not alone anymore. :laughing: :thumbsup:

 

[SPIKER]

So how does it feel to know that you are not alone anymore. :laughing: :thumbsup:

lol yep I'm sure more than most of us have been there done that but few admit to it in open forum lol...

Next step is to clean off top of tank sending unit to see if it drops back to low/showing actual level. Making an assumption as if I remember right these senders when grounded the gauge goes to full level.


Mark

 

[cleat]

My heating oil tank in the shop did the same thing sort of. Furnace quit and would not restart but gauge showed nearly 1/2 full.

After trying to get the furnace to light and then checking the filter I gave the tank a good bang with my hand and the gauge dropped. It was just stuck and tank was empty.

Got tank filled and furnace fired right back up.

Cleat