763 Bobcat---keeps dying HELP please

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farmslave

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Nov 30, 2013
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GOT troubles. Was having issues with it dying, inspected and replaced the brokeoff pickup tube, grommet and filter inside tank--(and have rechecked it and its still attached now). Replaced fuel filter. inspected and replaced fuel line to hand pump. inspected and replaced one fuel line to filter. replaced the lift pump for the fuel. Still dies. it will run perfect for about 15 minutes or so. then it acts like u shut the fuel off. it slowly just runs out of fuel and dies. the black hand pump is not sucked shut (I read to check that) and let it sit. come back, and fires up. 15 minutes or so later..it dies. I read about a coil heating up on another guys loader but it was a gasoline model. my diesel doesn't have one, ive been told. so it got me to thinking about maybe some other particular electronic item that is heating up and then fails. cools off, and I can restart. BUT I DONT KNOW. can I get sum advice please? thanks, amy
 

lfutrell

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May 29, 2011
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144
Sounds like you got a good start on this thing. Here is a couple things to check. The fuel lines run in a groove behind the fuel tank sometimes they get out of the groove and become pinched, check for water in the fuel, if conditions are right algae will grow in the fuel tank and that will plug filters as fast as you can put them on,could be a piece of something floating around in the tank that gets sucked over the pickup tube when it shuts down it floats away again, I would suggest you pull the tank and clean it thoroughly and put in new fuel and another new filter. check that the bleader screw on the inj. pump is closed.
 
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farmslave

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Nov 30, 2013
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Sounds like you got a good start on this thing. Here is a couple things to check. The fuel lines run in a groove behind the fuel tank sometimes they get out of the groove and become pinched, check for water in the fuel, if conditions are right algae will grow in the fuel tank and that will plug filters as fast as you can put them on,could be a piece of something floating around in the tank that gets sucked over the pickup tube when it shuts down it floats away again, I would suggest you pull the tank and clean it thoroughly and put in new fuel and another new filter. check that the bleader screw on the inj. pump is closed.
okay, when it warms up today or tomorrow, I will check on those fuel lines. Got a question....wud gasoline accidently being pumped into the thing cause this? wudnt it smoke, or run rough or something even at the beginning of start up? it wud not run perfect for 15 to 20 minutes if this was so? right? Becuz it does. Runs perfect and then it just slows down to a stop and dies. Not hydraulicly, im talking about it simply running then just as if u are throttling it down....and dies. So, if water or gas mixed into the diesel, I wud think it wud run rough at the start. Any ideas on that? cuz pulling the tank is not a five minute project.....
 

jerry

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May 3, 2007
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okay, when it warms up today or tomorrow, I will check on those fuel lines. Got a question....wud gasoline accidently being pumped into the thing cause this? wudnt it smoke, or run rough or something even at the beginning of start up? it wud not run perfect for 15 to 20 minutes if this was so? right? Becuz it does. Runs perfect and then it just slows down to a stop and dies. Not hydraulicly, im talking about it simply running then just as if u are throttling it down....and dies. So, if water or gas mixed into the diesel, I wud think it wud run rough at the start. Any ideas on that? cuz pulling the tank is not a five minute project.....
If you put a piece of tubing on the line just after the primer bulb does it flow freely when held lower than the tank level?
Next time it stops take the fuel cap off quickly and try to listen for suction in case the cap vent is bad. Or take it off and try to restart it right away.
 
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farmslave

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Nov 30, 2013
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If you put a piece of tubing on the line just after the primer bulb does it flow freely when held lower than the tank level?
Next time it stops take the fuel cap off quickly and try to listen for suction in case the cap vent is bad. Or take it off and try to restart it right away.
update>>I really needed to use it feed hay..so I took the chance. Got the chore done quickly..parked it. But thot lets c if it dies again, after about 15 minutes like all the times in recent past. Left it running wide open. Yup, it starts to die. I open back door, notice hand pump is not sucked shut. so, I twisted the shut off valve ( I think that's what its called) to closed position. and the engine RECOVERS!!!?! Runs perfect for bout a minute, then dies quick (runs out of fuel I determined) So, I open valve back up...it sits right above the lift pump. And try to restart. No luck. Squeeze black hand pump bulb several times, and notice that it never gets hard and completely full of fuel. I thot it shud gotten to point I cud not push fuel thru, but never did. maybe im wrong. repeated trying to start it, turnedover strong, never fired. took off hose coming out of valve, hand pumping made fuel flow out. reconnected. tried priming again. noluck. left it I bet, if I went and try, it wud start..its been several hours. usually will. then use 20 mins and hope it dies inside shop or barn---out of weather. ha the other day during an episode, I removed fuel and hydraulic caps, and air filters. no change. I really appreciate both replies and ALL help. I am not a know it all, and hope I can figure this out. its on my shoulders cuz husband health aint good
 

antfarmer2

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Oct 28, 2013
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update>>I really needed to use it feed hay..so I took the chance. Got the chore done quickly..parked it. But thot lets c if it dies again, after about 15 minutes like all the times in recent past. Left it running wide open. Yup, it starts to die. I open back door, notice hand pump is not sucked shut. so, I twisted the shut off valve ( I think that's what its called) to closed position. and the engine RECOVERS!!!?! Runs perfect for bout a minute, then dies quick (runs out of fuel I determined) So, I open valve back up...it sits right above the lift pump. And try to restart. No luck. Squeeze black hand pump bulb several times, and notice that it never gets hard and completely full of fuel. I thot it shud gotten to point I cud not push fuel thru, but never did. maybe im wrong. repeated trying to start it, turnedover strong, never fired. took off hose coming out of valve, hand pumping made fuel flow out. reconnected. tried priming again. noluck. left it I bet, if I went and try, it wud start..its been several hours. usually will. then use 20 mins and hope it dies inside shop or barn---out of weather. ha the other day during an episode, I removed fuel and hydraulic caps, and air filters. no change. I really appreciate both replies and ALL help. I am not a know it all, and hope I can figure this out. its on my shoulders cuz husband health aint good
That valve is to bleed the air out open to bleed sqush the ball then off to run may take a time or two to get the air out and check all lines for sucking air
 

Tazza

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update>>I really needed to use it feed hay..so I took the chance. Got the chore done quickly..parked it. But thot lets c if it dies again, after about 15 minutes like all the times in recent past. Left it running wide open. Yup, it starts to die. I open back door, notice hand pump is not sucked shut. so, I twisted the shut off valve ( I think that's what its called) to closed position. and the engine RECOVERS!!!?! Runs perfect for bout a minute, then dies quick (runs out of fuel I determined) So, I open valve back up...it sits right above the lift pump. And try to restart. No luck. Squeeze black hand pump bulb several times, and notice that it never gets hard and completely full of fuel. I thot it shud gotten to point I cud not push fuel thru, but never did. maybe im wrong. repeated trying to start it, turnedover strong, never fired. took off hose coming out of valve, hand pumping made fuel flow out. reconnected. tried priming again. noluck. left it I bet, if I went and try, it wud start..its been several hours. usually will. then use 20 mins and hope it dies inside shop or barn---out of weather. ha the other day during an episode, I removed fuel and hydraulic caps, and air filters. no change. I really appreciate both replies and ALL help. I am not a know it all, and hope I can figure this out. its on my shoulders cuz husband health aint good
That bleed screw should be fully closed.
The hand primer shoudl get hardwhen the system has been bled of all air, i wonder if there may be an issue with your lift pump too.
The odd thing is, it runs for quite a while before dying. Generally it happens faster than that if it's a pump or pickup tube.
 
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farmslave

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Nov 30, 2013
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That bleed screw should be fully closed.
The hand primer shoudl get hardwhen the system has been bled of all air, i wonder if there may be an issue with your lift pump too.
The odd thing is, it runs for quite a while before dying. Generally it happens faster than that if it's a pump or pickup tube.
yes, the fact it will run every time for about 15-20 minutes then die...is odd. The screw valve im talking about is located above the liftpump. there is a line going into the lift pump, and then coming out and going to this valve, then upwards to the injectors. screw it down, and its closed and no fuel passes thru. I took the lines loose to verify this. I am wondering how come it recovered when I closed it, then run out of fuel and died. so I reopended it and tried starting, no luck. But I was thinking, if it recovered when I shut off the fuel supply there then it must be sucking air before that, and then when I shut the valve, it stopped pulling air and had just fuel in the line AFTER it, and boom, it run fine until that amount of fuel was run out. There is no where for the air to go if it was just an air valve. there is a bleeder valve on the filter but im not talking about that valve. help someone has suggested a relay or other electrical component is heating up, and failing. then when it dies, cools off, then it will restart. I read to check the coil...if it was gasoline. but it aint so, what to check? any ideas there? becuz, like Tazza says, its odd for it to run perfect for that long then just die. The pickup tube has been replaced.
 
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farmslave

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Nov 30, 2013
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yes, the fact it will run every time for about 15-20 minutes then die...is odd. The screw valve im talking about is located above the liftpump. there is a line going into the lift pump, and then coming out and going to this valve, then upwards to the injectors. screw it down, and its closed and no fuel passes thru. I took the lines loose to verify this. I am wondering how come it recovered when I closed it, then run out of fuel and died. so I reopended it and tried starting, no luck. But I was thinking, if it recovered when I shut off the fuel supply there then it must be sucking air before that, and then when I shut the valve, it stopped pulling air and had just fuel in the line AFTER it, and boom, it run fine until that amount of fuel was run out. There is no where for the air to go if it was just an air valve. there is a bleeder valve on the filter but im not talking about that valve. help someone has suggested a relay or other electrical component is heating up, and failing. then when it dies, cools off, then it will restart. I read to check the coil...if it was gasoline. but it aint so, what to check? any ideas there? becuz, like Tazza says, its odd for it to run perfect for that long then just die. The pickup tube has been replaced.
just read something....does both valves need to be closed? then nothing will be able to flow from lift pump to it ...I took the line off, and when I hand squeeze pump, it flows out. Shut the valve and nothing flows. like I said...im not talking about the lower valve located on fuel filter.
 

antfarmer2

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just read something....does both valves need to be closed? then nothing will be able to flow from lift pump to it ...I took the line off, and when I hand squeeze pump, it flows out. Shut the valve and nothing flows. like I said...im not talking about the lower valve located on fuel filter.
No the one by the tank or filter needs to be open the one by the pump is to bleed out the air and needs to be shut after bleeding might take a few times to bleed to shut off turn to the right I would drain all the fuel and change the filter since your not sure about the fuel
 

antfarmer2

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Oct 28, 2013
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No the one by the tank or filter needs to be open the one by the pump is to bleed out the air and needs to be shut after bleeding might take a few times to bleed to shut off turn to the right I would drain all the fuel and change the filter since your not sure about the fuel
Also make sure you did not engage aux hydro
 

Tazza

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Is there a cup on the bottom of the fuel filter to empty?
I don;t know what other valve you have on your machine, there should be only one on the injector pump where the fuel comes in. There is a smaller hose running from this valve to the first injector on the head.
The idea is to open this valve, pump the hand primer, the fuel goes from the tank, through the hand primer, filter, lift pump, injector pump then to the tap off lines, back to the tank. With this valve open, you don't produce enough fuel pressure to keep the injector pump working happily. But the way you are talking, there is another valve that has been installed.
Can you get a picture of the valves?
Another thing you can try is to get a small jerry can of fuel, new hand primer from a boating or auto store, some fuel line. Remove the hose to the lift pump and install the new hose, put the hand primer in line and the other end in the fuel tank. Prime it and give it a run, see if it plays up. If so, it's your fuel line between the lift pump and tank, this included the filter.
 

flathead

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Dec 19, 2013
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I don;t know what other valve you have on your machine, there should be only one on the injector pump where the fuel comes in. There is a smaller hose running from this valve to the first injector on the head.
The idea is to open this valve, pump the hand primer, the fuel goes from the tank, through the hand primer, filter, lift pump, injector pump then to the tap off lines, back to the tank. With this valve open, you don't produce enough fuel pressure to keep the injector pump working happily. But the way you are talking, there is another valve that has been installed.
Can you get a picture of the valves?
Another thing you can try is to get a small jerry can of fuel, new hand primer from a boating or auto store, some fuel line. Remove the hose to the lift pump and install the new hose, put the hand primer in line and the other end in the fuel tank. Prime it and give it a run, see if it plays up. If so, it's your fuel line between the lift pump and tank, this included the filter.
Tazza there is a bleed valve in the fuel filter housing. And yes by all means gasoline mixed in with the diesel fuel will cause this same symptom, ive seen it happen many times, like tazza said bypass the fuel in the tank and try runnin it off of fresh fuel from a jerry can :)
 

TriHonu

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Tazza there is a bleed valve in the fuel filter housing. And yes by all means gasoline mixed in with the diesel fuel will cause this same symptom, ive seen it happen many times, like tazza said bypass the fuel in the tank and try runnin it off of fresh fuel from a jerry can :)
After it dies, did you check the fuel shut-off solenoid? The next time it dies, leave the key in the run position and check the fuel shut off valve. If the valve is closed you may have a solenoid that is failing. The solenoid has two coils, one to pull the valve open the second to hold the valve open. The hold coil may be heating up and opening. You can twist the shut-off valve open with your hand and jam a wedge or stick in behind it to hold it open then attempt to restart the engine. Just another possible cause of your problem.
 

Rodger

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Oct 30, 2012
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After it dies, did you check the fuel shut-off solenoid? The next time it dies, leave the key in the run position and check the fuel shut off valve. If the valve is closed you may have a solenoid that is failing. The solenoid has two coils, one to pull the valve open the second to hold the valve open. The hold coil may be heating up and opening. You can twist the shut-off valve open with your hand and jam a wedge or stick in behind it to hold it open then attempt to restart the engine. Just another possible cause of your problem.
I had a 555 New Holland do that several years ago . Turned out to be rad rags in the fuel tank .. actually about 6 . It would run fine , then die off . Previous owner etc must have lost a fuel cap and used red rags to cover . Even after taking the tank out ( what a pia ) , it did it . I fished another rag out with wire and it ran fine after that . I added an electric pump anyway . Sounds like a restriction that is not allowing the fuel to flow as fast as it is being used . If you run it slow , does it take longer to act up >
 

Tazza

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I had a 555 New Holland do that several years ago . Turned out to be rad rags in the fuel tank .. actually about 6 . It would run fine , then die off . Previous owner etc must have lost a fuel cap and used red rags to cover . Even after taking the tank out ( what a pia ) , it did it . I fished another rag out with wire and it ran fine after that . I added an electric pump anyway . Sounds like a restriction that is not allowing the fuel to flow as fast as it is being used . If you run it slow , does it take longer to act up >
I had a mchine that had no less than 3 filler necks from fuel drums in the fuel tank. Had a piece of hose in an oil tank..... No matter how random, there is always something out there that may supprise you.
 
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