bobcat 743 not fireing

[tooljim1]

this is whats going on i have a 743 bobcat what is going on is that i put in a new starter started up great run it for a few then when i went to go start it today it would not start it turns over and stuff the glow plugs are getting power and everything else is getting power but it wont fire ran yesterday just fine now it wont today it acts like it is not getting any fuel now i never changer the injectors could it be that they are now just to far gone when i took one of the metal fuel lines off just a little fuel came out so i dont no i took the metal line off and i went to turn the engine over to see if fuel would come out and there was no fuel coming out were i took the metal lines off so does this mean the fuel pump is bad

 

[Tazza]

It is very common for the fuel pickup tube to rot off. When this happens, you get no fuel.
There are two lines going into the tank, one is the main pickup, the other is the return line.

 

[mmsllc]

It is very common for the fuel pickup tube to rot off. When this happens, you get no fuel.
There are two lines going into the tank, one is the main pickup, the other is the return line.

Check the fuel system thoroughly. Mainly, check for fuel being present to the injection pump before condemning the injection pump. You also want to check the fuel shut down solenoid as it controls fuel through the injection pump. Fuses are another helpful thing to check. Start by checking all of the fuses. Remove each fuse one at a time. Hold them up to a light to see if they are blown or use a test light to probe both sides of each fuse for power. Then, move on to the fuel shut down solenoid. Have a friend / helper turn the key to the "ON" position while watching for movement. If it does not move, use a test light for proper power to the solenoid. If you have power, the fuel shutdown solenoid should pull inwards. If you have power & it does not pull in, the solenoid is most likely BAD. If it does pull inwards, move on to the fuel supply system to the engine. To do this, remove the rubber fuel line to the fuel filter. Squeeze the primer bulb a few times. Did any thing come out? If not the problem is between the end of the fuel line & the fuel tank AND everything in between. (For instance, I've seen the fuel pick up tube fall off & the fuel supply to the engine was interrupted because of that. I've also seen air leaks at the priming squeeze bulb where the engine ran poorly because it was not getting solid fuel. My point is that the problem is most likely a simple / cheap repair. Try the above steps to better help us understand the issue at hand.

 

[unclebill]

Check the fuel system thoroughly. Mainly, check for fuel being present to the injection pump before condemning the injection pump. You also want to check the fuel shut down solenoid as it controls fuel through the injection pump. Fuses are another helpful thing to check. Start by checking all of the fuses. Remove each fuse one at a time. Hold them up to a light to see if they are blown or use a test light to probe both sides of each fuse for power. Then, move on to the fuel shut down solenoid. Have a friend / helper turn the key to the "ON" position while watching for movement. If it does not move, use a test light for proper power to the solenoid. If you have power, the fuel shutdown solenoid should pull inwards. If you have power & it does not pull in, the solenoid is most likely BAD. If it does pull inwards, move on to the fuel supply system to the engine. To do this, remove the rubber fuel line to the fuel filter. Squeeze the primer bulb a few times. Did any thing come out? If not the problem is between the end of the fuel line & the fuel tank AND everything in between. (For instance, I've seen the fuel pick up tube fall off & the fuel supply to the engine was interrupted because of that. I've also seen air leaks at the priming squeeze bulb where the engine ran poorly because it was not getting solid fuel. My point is that the problem is most likely a simple / cheap repair. Try the above steps to better help us understand the issue at hand.

I had a similar problem last winter, and it was the fuel pickup tube. Here's a link to my post, and what I ended up doing...hope it helps. B http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=84084

 

[mmsllc]

I had a similar problem last winter, and it was the fuel pickup tube. Here's a link to my post, and what I ended up doing...hope it helps. B http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=84084

Yeah. That fuel pick up tube is a huge problem for mist bobcats. Have you ever tried to change one on a 863? They have such limited access that considering pulling the engine becomes a real possibility.

 

[lesgawlik]

Yeah. That fuel pick up tube is a huge problem for mist bobcats. Have you ever tried to change one on a 863? They have such limited access that considering pulling the engine becomes a real possibility.

I saw a fantastic post about how to get around the fuel pickup problem. The filler tube is split and a 1" section is removed. The section is replaced with a section of stainless tubing, and later secured by hose clamps. Before the stainless section is installed, a flat area of about 3/4" diameter is hammered in the middle of the length of the tube, and a hole drilled through the tube. A stainless through-fitting with barbs on both ends is screwed into the hole. A length of fuel line with the pickup is run down the open filler tube into the tank, and the other end is secured to the inner barb of the through fitting. Put the stainless section into the filler tube, and secure with clamps. Press the fuel line to the engine onto the barb fitting on the outside of the stainless section, and you're done. In essence, you're running the fuel line through the filler tube, and daylighting it through a section of stainless tubing spliced into the filler tube. I thought that was absolute genius, and I just wish I had saved the pictures.

 

[rodbuilder]

1. Tie the injector pump fuel shut-off lever to the "run" position (or right) and try starting it. Or, you can also turn on the key and go to the engine room and see if the solenoid is pulling the lever all the way over to the right. 2. If you do #1 and it runs or if the shut off lever isn't going all the way to the right with the solenoid, then you have a bad shut-off solenoid.......and they're NOT cheap! 3. If it doesn't run leave the lever tied like it is and remove the air filter cover and give it a WHISP of ether. Just a tiny bit!!! Then try it again. 4. If it fires you have a fuel problem. Like you suggest - maybe a pickup problem in the tank, or it might be as simple as a fuel filter, so try that first. 5. If it fires with ether it's probably a bad fuel shut-off solenoid and you can convert the troublesome $208 piece of junk over to a cable shutoff for as little as $25. NAPA has all the stuff to do it except for a simple bracket you can make out of a small piece of angle iron. Personally I'd foot for the Nylon-lined Morse cable they sell for $53, like the one I just put on a 773.

 

[SkidRoe]

1. Tie the injector pump fuel shut-off lever to the "run" position (or right) and try starting it. Or, you can also turn on the key and go to the engine room and see if the solenoid is pulling the lever all the way over to the right. 2. If you do #1 and it runs or if the shut off lever isn't going all the way to the right with the solenoid, then you have a bad shut-off solenoid.......and they're NOT cheap! 3. If it doesn't run leave the lever tied like it is and remove the air filter cover and give it a WHISP of ether. Just a tiny bit!!! Then try it again. 4. If it fires you have a fuel problem. Like you suggest - maybe a pickup problem in the tank, or it might be as simple as a fuel filter, so try that first. 5. If it fires with ether it's probably a bad fuel shut-off solenoid and you can convert the troublesome $208 piece of junk over to a cable shutoff for as little as $25. NAPA has all the stuff to do it except for a simple bracket you can make out of a small piece of angle iron. Personally I'd foot for the Nylon-lined Morse cable they sell for $53, like the one I just put on a 773.

Just to expand on rodbuilder's post, is your machine a 743 or a 743b? If it is a 743, it should already have a cable operated shut off. Be sure that the cable isn't binding and that when you push it in that you are moving the shut off lever all the way to the run position, as rb suggests. HTH - SR