763 - goes Blam - Tango uniform?

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carl johansson

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Nov 5, 2007
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So I'm working away on my 763 - it has been flawless in the 10 hours since I swapped in a used 2203. temps look great - stays below 1/2, pressures look good, no warning lights, starts up immediately, the thing is running like a champ! all of a sudden - in the middle of the road - bang - it goes dead - not like it sputters and dies - it goes from running perfectly at 2/3 throttle - to dead - in 1/10th of a second. I try the key - nothing - so I'm assuming it must be electrical? anybody have some wisdom or experience they can share to help me out? Lucky the road was muddy - I skidded it out of the road using my 3/4 ton pickup - otherwise the wife would have had a 1/2 mile walk to the house! Carl Johansson
 
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carl johansson

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I can't seem to edit my post - sorry. 2 pieces of info that might help. 1. No BOSS sysytem - pre boss electronics 2. I replaced the seat with a new one about 3 hours ago
 

TriHonu

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Apr 15, 2007
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I can't seem to edit my post - sorry. 2 pieces of info that might help. 1. No BOSS sysytem - pre boss electronics 2. I replaced the seat with a new one about 3 hours ago
Did the engine make any noises as it died?
Did you check all the fuses and voltages at battery, starter, fuel solenoid?
Did you carefully check the main harness around engine and belts/moving parts?
To kill a diesel, you either have to have a mechanical problem or no fuel. Loss of power to the fuel solenoid will stop the engine as you describe.
Since you seem to have lost some electrical, you need to check the basics and try to narrow the possible problems. Let us know.
 
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carl johansson

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Did the engine make any noises as it died?
Did you check all the fuses and voltages at battery, starter, fuel solenoid?
Did you carefully check the main harness around engine and belts/moving parts?
To kill a diesel, you either have to have a mechanical problem or no fuel. Loss of power to the fuel solenoid will stop the engine as you describe.
Since you seem to have lost some electrical, you need to check the basics and try to narrow the possible problems. Let us know.
Haven't checked anything, it just quit - and now it's dark. I guess I will start diagnosing tommorrow. I heard like a metalic bang - but I think that was from the hydraulics locking up - it died quicker than if you turned the key off. fuel bulb is hard as a rock and fuel guage read 1/2 full - I will check the solenoid! Doubt if it's the battery - no drag on in starting at all - and it holds a charge just fine. carl Johansson
 

Tazza

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Haven't checked anything, it just quit - and now it's dark. I guess I will start diagnosing tommorrow. I heard like a metalic bang - but I think that was from the hydraulics locking up - it died quicker than if you turned the key off. fuel bulb is hard as a rock and fuel guage read 1/2 full - I will check the solenoid! Doubt if it's the battery - no drag on in starting at all - and it holds a charge just fine. carl Johansson
A metalic bang as you said sounds like it could even be the park brake kicking in.
I would start by holding the fuel cut off solenoid back and jump the starter to the solenoid and make sure the engine starts, or at least cranks and puffs smoke. If it does it sounds like its not the engine. Loosing power would let the brake snap on and it would make a bad noise!.
 
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carl johansson

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A metalic bang as you said sounds like it could even be the park brake kicking in.
I would start by holding the fuel cut off solenoid back and jump the starter to the solenoid and make sure the engine starts, or at least cranks and puffs smoke. If it does it sounds like its not the engine. Loosing power would let the brake snap on and it would make a bad noise!.
I was thinking about this last night. If it was a fuel problem solenoid or other - wouldn't the engine try to crank when I turned the key? turn the key gets exactly nothing - no clicks no grings no lurches - nothing. i know very little about diesels - but if that happened in a gasoline engine I would be looking at ignition switch and ignition. I think Tarzas probably right - I would guess the bang I heard was the parking brake locking down. If for some reason the parking brake locked down while it was running - and moving - I guess that would kill the engine- right - but It wouldn't stop it from firing back up - right? Thanks for all the help so far! Carl Johansson
 

mllud

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Jun 29, 2007
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I was thinking about this last night. If it was a fuel problem solenoid or other - wouldn't the engine try to crank when I turned the key? turn the key gets exactly nothing - no clicks no grings no lurches - nothing. i know very little about diesels - but if that happened in a gasoline engine I would be looking at ignition switch and ignition. I think Tarzas probably right - I would guess the bang I heard was the parking brake locking down. If for some reason the parking brake locked down while it was running - and moving - I guess that would kill the engine- right - but It wouldn't stop it from firing back up - right? Thanks for all the help so far! Carl Johansson
Carl: You recently replaced your seat . Maybe something with safety switches in the seat? Mike
 

skidsteer.ca

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Jan 20, 2006
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I was thinking about this last night. If it was a fuel problem solenoid or other - wouldn't the engine try to crank when I turned the key? turn the key gets exactly nothing - no clicks no grings no lurches - nothing. i know very little about diesels - but if that happened in a gasoline engine I would be looking at ignition switch and ignition. I think Tarzas probably right - I would guess the bang I heard was the parking brake locking down. If for some reason the parking brake locked down while it was running - and moving - I guess that would kill the engine- right - but It wouldn't stop it from firing back up - right? Thanks for all the help so far! Carl Johansson
If you lose you main power, the park brake and fuel soliniods would both release , shuing off the fuel and slamming the park pin on.
Try turning the engine by hand a couple turns. The tie on the fuel solinoid and jump the starter. If it sounds ok, then lift the cab and remove the park brake solinoid and the rod from under it so you can drive it home.
Sure sounds like a wiring failure to me to
Ken
 

Butters

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Jan 23, 2007
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If you lose you main power, the park brake and fuel soliniods would both release , shuing off the fuel and slamming the park pin on.
Try turning the engine by hand a couple turns. The tie on the fuel solinoid and jump the starter. If it sounds ok, then lift the cab and remove the park brake solinoid and the rod from under it so you can drive it home.
Sure sounds like a wiring failure to me to
Ken
My 751 C did the exact same thing last year. It blew one of the main fuses. I replace the fuse and soon as I turned the key it popped the fuse again, at least the fuse was doing what it was supposed to.
I didn't have time, patience, or know how, so I calle bobcat and they came out and traced it to the hour meter causing the short. It had about 350 hours on the origional meter and they replaced it with a new one and everything has worked perfectly since then.
 
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carl johansson

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My 751 C did the exact same thing last year. It blew one of the main fuses. I replace the fuse and soon as I turned the key it popped the fuse again, at least the fuse was doing what it was supposed to.
I didn't have time, patience, or know how, so I calle bobcat and they came out and traced it to the hour meter causing the short. It had about 350 hours on the origional meter and they replaced it with a new one and everything has worked perfectly since then.
Bingo - we have a winner! The 15 amp fuse blew. but if the fuse blew - that would not stop the loader from running would it? at least not the immediate stop. So heres how I think it came down. I start the loader and get to work - the fuse blows sometime during my work expedition, loader keeps working like a champ - I eventually overload the hydraulics and it dies due to the overload, Now when I try to start it - nothing - birds singing, frogs chirping - nothing - not even a click is heard. So I replace the fuse - and it immediiately fires up - and runs perfect again. So now my question is - what caused the fuse to blow - and why hasen't it blown again? is it just a matter of time. On farm tractors and other equipment sometimes the fuses blow for no reason - probably vibration, but usually the blown fuse says I've got an electrical issue somewhere! I'll keep running it itll it blows again - then I guess I have to start looking! Butters - thanks - first place I will look is the hobbs meter - which BTW quit at exactly 2200 hours when it stalled - i figured it was preprogrammed into the machine by Bobcat - to make me take it in for an expensive service call and start thinking about a new machine! (OK so the conspiracy parts a bit of a strech!) Thanks again guys Carl Johansson
 

skidsteer.ca

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Bingo - we have a winner! The 15 amp fuse blew. but if the fuse blew - that would not stop the loader from running would it? at least not the immediate stop. So heres how I think it came down. I start the loader and get to work - the fuse blows sometime during my work expedition, loader keeps working like a champ - I eventually overload the hydraulics and it dies due to the overload, Now when I try to start it - nothing - birds singing, frogs chirping - nothing - not even a click is heard. So I replace the fuse - and it immediiately fires up - and runs perfect again. So now my question is - what caused the fuse to blow - and why hasen't it blown again? is it just a matter of time. On farm tractors and other equipment sometimes the fuses blow for no reason - probably vibration, but usually the blown fuse says I've got an electrical issue somewhere! I'll keep running it itll it blows again - then I guess I have to start looking! Butters - thanks - first place I will look is the hobbs meter - which BTW quit at exactly 2200 hours when it stalled - i figured it was preprogrammed into the machine by Bobcat - to make me take it in for an expensive service call and start thinking about a new machine! (OK so the conspiracy parts a bit of a strech!) Thanks again guys Carl Johansson
Usually there is a reason but sometimes a popped fuse just happens too.
Unless it happens again, likely just forget it.
You could search your entire wire harness for exposed wires, or test the dead hour meter to see if it shorted to ground But if that was the case the problem should still exist.
My vote is keep a couple 15 amps handy, leavn how to disable your park brake, tie the fuel shut off lever on and start it by crossing the starter. Then if it happens again you will be able to get it back home at least. All this can all be done in 15 minutes with a few hand tools.
Ken
 
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