CK2610 looses power at half tank fuel

[alexpops]

I wouldn't settle for living with it, I'd try to figure out what is going on & fix the problem so it doesn't happen again.

 

[paulsharvey]

I did a quick check last night for any pinched lines, and from the tank to the deck "tunnel" good, and from the "tunnel" to the lift pump and lift, good. I haven't pulled the deck "tunnel" cover yet, to check there.

 

[rScotty]

Could air really stay in the system that long, and then affect the machine when it gets to half tank? Anytime I've ever dealt with air in a diesel fuel system, once it would run, it completely purged any remaining air.

My thinking was A; it's just having trouble making it to pick up on a slope, and it's a live with it thing
or B; at half tank, it lakes the 'head pressure' to make it past a restriction.

Should be fine. Diesels are tough that way since they naturally operate on the lean side of the fuel/air curve.
But that is so simple of a system we should be able to fix it easily. It wasn’t made to work that way. Either the pump is weak or one of the standpipes has a problem. It is not a crimped hose; crimps affect rate of flow, but not head pressure at low flow rates.

What does bother me is the flow diagram shows the pump as being before the filter. That is either a novice engineer’s design mistake or else the drawing is wrong….
rScotty

 

[paulsharvey]

So, I'll rebook at the schematic, but I'm looking at machine right now, fuel comes all the way from the tank, down hill, then up hill to the filter, then down to the pump, then from pump upto the injector pump.

Makes me wonder about a "double p trap" situation?

 

[alexpops]

That changes things a little. Like rScotty said, this is the more usual setup (with Racors, you always want them on the vacuum side of the pump) As long as the filter head is @ or below the level of fuel in your tank, fluid will flow to fill the filter since it seeks to equalize elevation of fluid.

SO ... how is #9 (bleeding hose) used? Is there a diaphragm pump on top of filter head to suck fuel/air from top of filter & purge back to tank? Is the gasket seal between the filter head and the diaphragm good? Is the check valve sealing? If the gasket between the pump/diaphragm and filter head or the check valve isn't sealing, you could be sucking air when the pump suction overcomes the "head" of the fuel level in the tank. First thing I would check is that all screws/bolts holding the filter purge pump are tight and the gasket looks even all the way around.

If you have a t-handle style purge pump, check the o-rings and the seal when you screw it down tight.

If neither of those does the trick, look at the check valve in the pump for something not letting it seal completely.

In your original schematic, I assumed a valve was opened/closed & FP pressure was used to purge the filter.

 

[LouNY]

Have you unscrewed the fuel cap when it starts to bog down.

 

[paulsharvey]

Have you unscrewed the fuel cap when it starts to bog down.

No, and I did wonder about that,

 

[paulsharvey]

That changes things a little. Like rScotty said, this is the more usual setup (with Racors, you always want them on the vacuum side of the pump) As long as the filter head is @ or below the level of fuel in your tank, fluid will flow to fill the filter since it seeks to equalize elevation of fluid.

SO ... how is #9 (bleeding hose) used? Is there a diaphragm pump on top of filter head to suck fuel/air from top of filter & purge back to tank? Is the gasket seal between the filter head and the diaphragm good? Is the check valve sealing? If the gasket between the pump/diaphragm and filter head or the check valve isn't sealing, you could be sucking air when the pump suction overcomes the "head" of the fuel level in the tank. First thing I would check is that all screws/bolts holding the filter purge pump are tight and the gasket looks even all the way around.

If you have a t-handle style purge pump, check the o-rings and the seal when you screw it down tight.

If neither of those does the trick, look at the check valve in the pump for something not letting it seal completely.

In your original schematic, I assumed a valve was opened/closed & FP pressure was used to purge the filter.

I'm going to have to reread this while looking at the system. I have to be looking at it, and kinda go piece by piece through what you posted.

 

[rScotty]

So, I'll rebook at the schematic, but I'm looking at machine right now, fuel comes all the way from the tank, down hill, then up hill to the filter, then down to the pump, then from pump upto the injector pump.

Makes me wonder about a "double p trap" situation?

I doubt it is the fuel bleed line. But that is easy enough to check. Check it with a hose and a clear mustard jar just like you do the bleeder valve on automotive brakes to get air out of the brake cylinder.

But you may want to take another look at the schematic you posted. Your description while looking at the machine didn't include #7, the fuel feed pump - also called a "lift pump". That pump puts a positive pressure on all the components that come after it. So not "p trap" situation can exist after the lift pump.

There's a problem though.... That schematic diagram you posted might be drawn wrong by the original illustrator....I'm saying that the schematic itself might be in error. It wouldn't hurt to check that out by looking at the fuel system and comparing it with the schematic. Normally mechanical design is to put the filter before the pump. Doing it with the pump before the filter - like the schematic illustration shows - doesn't make sense & my guess is a drawing mistake.

I think this is fixable if you want. I also think it won't make much difference if you don't.

rScotty

 

[rodneyn]

I doubt it is the fuel bleed line. But that is easy enough to check. Check it with a hose and a clear mustard jar just like you do the bleeder valve on automotive brakes to get air out of the brake cylinder.

But you may want to take another look at the schematic you posted. Your description while looking at the machine didn't include #7, the fuel feed pump - also called a "lift pump". That pump puts a positive pressure on all the components that come after it. So not "p trap" situation can exist after the lift pump.

There's a problem though.... That schematic diagram you posted might be drawn wrong by the original illustrator....I'm saying that the schematic itself might be in error. It wouldn't hurt to check that out by looking at the fuel system and comparing it with the schematic. Normally mechanical design is to put the filter before the pump. Doing it with the pump before the filter - like the schematic illustration shows - doesn't make sense & my guess is a drawing mistake.

I think this is fixable if you want. I also think it won't make much difference if you don't.

rScotty

I had lk3054 kioti with same issues start losing power at 1/4 tank. My issues were both filler cap and a collapsed fuel line under vacuum from the bad filler cap. Too cheap to purchase new cap. I vented it with sintered brass plug. Replaced fuel lines problems subsided. However year later lift pump started leaking. I did replace that. Traded that tractor at 1900 hours my neighbor uses it daily in horse barn. Thanking me for selling it to him at trade in value. Tough tractor good value. It lives on probably longer than me in the end. Early models were quite overbuilt it was 1995 model.