Question regarding Bobcat 743

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KSsteve

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Joined
Dec 26, 2006
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27
I have posted here about a hard starting 743. Well, I was working at getting it started yesterday and found a way to get it started. While someone was cranking the engine, I was pumping the primer bulb on the fuel line and it started. (It was still stubborn, but it worked. What do you think would cause this? Injection pump? Fuel pump if there is one? Once it's started it runs good and can sit for a few hours and no problems. Let it sit overnight and you have to pump the bulb again. Thanks, Steve
 

Tazza

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Dec 7, 2004
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The first thing i would check would be the bleed valve on the injector pump. Have a look where the main fuel line goes into the pump, there should be a valve on top that goes to the tap off lines to the injectors. Make sure this valve is fully closed, turn it clockwise. If its not fully closed, the lift pump will not be able to supply enough pressure to the pump at cranking speed. But when running it would probably get enough fuel.
I would start there, if that fails i would check for leaks in the fuel lines. It may be drawing in air, maybe even in the fuel tank pickup tube.
You can easily check fuel pressure from the lift pump which is located on the left near the coolant drain plug. Just un-hook the hose at the injector ans see if you get a bit of pressure when you hold your finger over it and crank the engine.
You way also want to check the fuel filter.
 

Butters

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Joined
Jan 23, 2007
Messages
72
The first thing i would check would be the bleed valve on the injector pump. Have a look where the main fuel line goes into the pump, there should be a valve on top that goes to the tap off lines to the injectors. Make sure this valve is fully closed, turn it clockwise. If its not fully closed, the lift pump will not be able to supply enough pressure to the pump at cranking speed. But when running it would probably get enough fuel.
I would start there, if that fails i would check for leaks in the fuel lines. It may be drawing in air, maybe even in the fuel tank pickup tube.
You can easily check fuel pressure from the lift pump which is located on the left near the coolant drain plug. Just un-hook the hose at the injector ans see if you get a bit of pressure when you hold your finger over it and crank the engine.
You way also want to check the fuel filter.
My 751-C just started doing the same thing. I will look at this. Thanks.
 
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