When I get my machine in a nose down condition I believe the fuel outlet at the tank is sucking air which results in low power and stalling. Is there a device I can install which will burp the air out of the fuel line to the injector pump? Any recommendations?
What kind of machine is it ? That shouldn't happen unless it is very low on fuel in tank.
Don't patch a problem... figure out what the problem is ... I had a diesel that would spit & sputter depending on machine position too. Root cause was a leaking fuel pick up hose in the tank. It would suck air. Replaced hose, problem fixed.
takeuchi ctl
Are you sure it is an air problem ? Or is there something sliding around in the fuel tank. I have seen everything from rags to weeds in fuel tanks.
No I'm not. In fact today it's doing it all the time even with a full tank. So, I don't know I've also thought maybe the fuel is getting hot. I'll try blowing out the suction line.
Have you inspected the fuel filters? Is there an in-line fuel filter before the lift/primer pump? Check the fuel line between the lift/primer pump for fuel flow / blockage - & clear it by blowing compressed air down it, back into the tank.
Yes. Changed both filters, cleaned separator, cleaned banjo fittings. I've blown out the suction line before with mixed results. Thing is it comes and goes. Seems to do it less when cold. Almost always does it when nose down but today even on the flat. I think I'll flip separator upside down and see if air actually accumulates. Pretty sure dropping/inspecting the tank is a big job.
Actually, I think I'll first put a pressure gauge in the separator and see what pressure is.
do you have any rubber hoses from the tank to the injection pump, i have had and seen hoses start breaking down inside and cause this problem
Yes, I do. That's an interesting one. Pressure gauge should help find that.
You need to pull out the tank outlet, after draining the tank. Had to it on all my Takeuchi CTLs. I'll be back with the thread link...
13th post down...whole thread worth reading HeavyEquipmentForums
Thanks!
Pulled outlet at tank and it was clean. Blew out line back to pump. Could not get it primed... come to find out I think the lift pump was bad. Took it apart and it hasn't missed a beat all day!
Going to call it FIXED! Lift pump was only working intermittantly.
I'm baaaaaaack! Downhill fuel problem persists!. I stuck the machine in a hole and it stalled. Fuel tank was probably about a quarter full. Disconnected fuel pump outlet and it was sputtering but not really pumping. Dumped separator and pump would not re fill separator. Filled fuel tank full and separator filled and machine ran fine. I think that port at the back of the tank that is piped to the "To Injection Pump (Out)" is getting exposed to air when front down machine position and that is what's causing the problem. What is the purpose of this line... should there be a check valve in it?
Also, anyone know the purpose of the pipe connected at 'X'?
X is just a filler neck vent. It's small to get you to shut off with a small amount of air left, then it will equalize to keep from burping fuel out the filler neck. "to injection pump (out)" would only have a check valve at the injection pump, it shouldn't cause stalling while running. I'd focus on the supply line in the tank, or a vacuum leak between the tank and injection pump, or a floater in the tank that stays safely out of the way when the tank is full. Key to that was if the pump was pumping air and sputtering fuel when it wouldn't pump, or if it was pumping nothing. Foam bubbles is an easy way to tell if it's pumping air, remember the air volume will be much less than fuel volume out of any fuel pump, they're not good at it.
I've been reading this "new to me " thread, i would strongly recommend replacing the fuel hose from the tank to the separator and from the separator to the lift pump. If you can find hose similar to parker push-loc, all the better. You want to stay away from natural rubber products. As mentioned earlier, Catman13, the rubber breaks down. The challenge is, you'll never see a leak. You either replace with known good hose or always have that as an unknown variable. Good luck.
If a new transfer pump eliminated the problem for a short time I would be looking for an obstruction in it or a problem with the suction line between it and the fuel tank outlet. Filling the tank and then the machine runs fine indicates a problem with the new transfer pump. Maybe ! When it is running check it for full voltage. There is remote chance there is low voltage situation when the machine is in that downhill angle.
I don't understand the physics of the vent... what causes fuel to flow up that line before the actual fill hole? My thinking on the "injection pump out" line is that if it's at all connected to the suction side of the pump and got air in it it could cause a problem. I know there is at least one return from the injection pump back to the separator but I don't know if the two lines are somehow connected with a check valve in between.
Sorry, X is an AIR vent, just lets the air out as you fill the tank. The diagram doesn't show a return from the injection pump back to the separator, but some filter set ups would tie the return back to the filter and work. I assume they had an orifice somewhere or were just ballanced so the some flow would return to the tank, I don't know, never bothered to figure it out because it never caused issues. I, along with funwithfuel and tinkerer still think your issue is most likely upstream of the transfer pump. Either leaking air or blocked.
Is it possible to just make a new fuel pickup for the tank? Like a long piece of copper with a bunch of holes drilled and the end pinched off so that if it is a plastic wrapper in the tank or something, it can't plug them all at once. Just an idea.
You mean like post 13 in the thread I quoted earlier in here. HeavyEquipmentForums
For the most part fuel doesn't go up the vent line. Only air that is forced out of the tank by the fuel going in. If you kept putting fuel in the filler tube after the tank is full then fuel would begin to go up the vent at the same level as the fuel in the filler tube. Your parts drawing shows the (to the injection pump -out-) line as simple direct route from the pump to the fuel tank. I don't think it has anything to do with your problem. Look at the injection pump in the parts book for that OUT line. See if it shows any other lines connected to it. I'm guessing there is none.
I really don't think it's a line or trash issue because the separator, banjo fittings, and filter at lift pump are all clean and I've never seen any evidence of hose pieces.
That's what I would think... but, the fuel is visible in the filler neck pouring out the vent before the fill line... that's how I know when to stop filling. It's very handy, just wish I knew how it worked.
This thing's really got me, ran all morning in some serious downhill situations and never missed a beat!
Have you the means to put about 4-5 psi into the fuel tank while closing off the return line? You don't necessarily see bits, or anything else. The line can be closing shut like a clogged artery and you won't know by looking at it. Only when you cut it open end to end do you see if that was the cause. What you get is a crack in a dry rotted hose that will suck air and not leak fuel. The pressure will cause a crack to finally leak fuel. The other possibility is that the water separator is pulling air in. Both are common failure points and to flatly discount either one without proving that it is not the problem is a sure way to keep changing parts.
The next time it acts up pull the hose off the water separator that comes from tank and see how much fuel flow you have . If you can get it below the tank. Bob
Ah, I see what you're saying but if it was a bad hose the problem should be there all the time...not just when downhill? The hoses are pretty secure so it's not like they're floating around and changing position when downhill.
That's a good idea but it only does it when the front is down so it won't drain. This is why I'm really thinking it's the lift pump pulling air from somewhere when the front is downhill. The only place I can see where the fuel level changes to possibly expose any part of the system is that return line from the injection pump. I'm thinking it does it too when real low on fuel which would support my thinking but I'm not real sure since I usually keep it above 1/2 tank.
What model Takeuchi is it ? It would be very easy to remove the lift pump supply line and substitute another line temporarily to determine if it is the culprit. You need to start eliminating that kind of possibility until you find the problem.
It's a TL140
Is there any chance the fuel supply line to the transfer pump is not attached to the outlet on the bottom of the fuel tank ? What I'm questioning is, if someone has the injection pump outlet connected to the bottom of the tank and unwittingly has the transfer pump supply line connected higher up on the tank where the overflow line should be.
WHOA! Good thinking, I'll check it out.
One off the wall idea is, how does the air get into the tank when the fuel is drawn out? We had a John Deere back hoe at the quarry that every so often would loose power and the problem was the fuel cap had a small breather filter maybe 1/2 inch around that looked like a bunch of fine brass beads stuck together. It would get plugged with mud or dust and cause fuel starvation problems. Made it a habit of any time I was working on it to spray carb cleaner and air through the breather filter.
Thanks. I've tried it with the fuel cap loose and it didn't fix it so I suspect the vent is working.
On a TL140 is the feed pump ( below radiator)suppose to have constant power or just when starting for 30 seconds I thought I read 30 seconds when starting mine has 12v constant.
Someone say Air Eliminator? This is my big yellow air eliminator. Liquid Controls optic style. It looks for air bubbles and purges when needed. I don’t sell air, only diesel. No mechanical float or reed valves to break. Wait, what? You fellas are talking about something else. My bad. Carry on.
constant
Thank you I will fix that will it is down waiting on parts
I once had a 3inch long piece of black electrical tape floating around in a fuel tank. Took me years to finally find that bit**. It might run a year, or an hour or any combination therein.
I have had my TL for 8 years and it only had power to air out feed pump for 30 seconds before start up run fine unless going up or down hill maybe this will fix the problem with that
think i finally got it. turned separator upside down and was able to bubbles entering separator. Tightened banjos and bubbles stopped.