I Have to Bobcat 7753 Continue Squeezing Bulb to Run

1. My bobcat will start fine and run for a minute or 2 before dying out. It doesn't want to restart after this without using the primer bulb. the pickup in the tank is new as well as the filter. I drained the tank and have fresh diesel. I noticed it drained the battery fairly fast while trying to fix it. Any suggestions are appreciated. Thank you

2. Remove the lines going into & out of the filter head if they're banjo bolt style connectors..
   They usually have screens in them..
   If the batteries are weak & not charging, you might be loosing power to the shut-off solenoid on the inj. pump..
   You said, the PICK UP is new.. what about a lift pump/supply pump?? does it have a "helper pump" between the tank & filter or is it gravity fed??

3. Ill test the batteries before trying this again. The only pump is on the back of the motor right before the filter. I replaced it a while ago, but will check it also. The lines t the filter just slip over fittings and have hose clamps on them, is there a screen on the top of the fuel filter holder? Thanks

4. what model machine?
   rectangular or triangular headlights?

   

5. It's a 1999. It has triangle headlights.

6. get the fuel system primed up, and get the engine started, run up to full throttle. keep an eye on the primer bulb as the engine starts to die out.
   is it collapsing? if it is,
   the pickup hose/screen is plugged inside the tank, or the fuel cap vent is plugged
   if it's not,
   start pumping the primer and see if the engine RPM recovers. that indicates a bad fuel lift pump

   

7. Tried the pumping the bulb and that worked. Put a new fuel pump in today. Started it up and it ran for a while. Went to restart it and the battery wouldn't turn it over. Time for a new battery. Any suggestion on a good battery? Bobcat seems a little high on their prices. Thanks.

8. 

   Delmer Senior Member

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   Why do you think the battery is bad and not the charging system? If it starts cold but drains the battery running, that seems like it's not charging to me...

   What's the voltage when it's running?

9. If we are both reading this the way it sounds I would agree that first place to check is the charging system. Along with all the basics like cleaning battery terminals, wiring to starter and ground strap and such. And if it's not a sealed battery check the water/acid level in that.

   As for a battery I would find out what the battery Bobcat suggests, CCA's and so on. Possibly a Group 24, 650CCA and Reserve Cranking at 25A of 115. But this list also shows some 773's using a 31A battery so you need to look into what yours should use.
   http://landing.bobcat.com/parts/static/pdf/Bobcat_batteries.pdf

10. I charged the battery for 2 hours and it started once. When I tried to restart it it wouldn't even turn over. I'm going with the battery being bad. I've got it charging now and I'll have the autoparts store Test it.

11. 

    Delmer Senior Member

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    If "a while" is less than 2 minutes, then maybe. If it was running longer than that, I still say your charging system is the first place to check. Or, charge the battery till full, let it sit 24 hours not hooked up, then see if it will start the engine.

12. definitely need toclean the cable ends, battery posts, and check the charging system. at idle you should see 14.3- 14.6 at idle.

    we sell a lot of bobcat batteries, at least 50% of them to someone who recently bought and installed an aftermarket battery. as mentioned there are 2 different batteries that could be in your machine. a 650CCA (24 series) and a larger 31 series. bobcat's 31 series is now 1000CCA. the larger battery was an option, "std" battery was the 650CCA. there are 2 different battery trays, hold down clamp and bolts are the same.

13. Will try charging the battery again. I've cleaned both ends of the positive and negative cables and where they attach. Not sure what the CCA is on the battery as the label is no longer on it. The water/acid level is good. Thanks for the great advice.

14. Tried running it again and the battery turned it over more than once. It still only ran for a few minutes and wouldn't start again. I noticed that the primer bulb had air in it so I primed the system again. It ran for a bit and died. the bulb had air in it again. its a new primer bulb and pump. Could it be a hole in the fuel line letting air in but not fuel out? possibly the line from the tank to the pump?

15. 

    Delmer Senior Member

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    Yes, the tank to the pump is the most likely place to leak, after the pickup tube in the tank. Yes, if it's under suction it won't leak fuel out, but leak air in.

    You said you drained the tank, did it have any junk come out with the old diesel? and did you flush the old tank out? or vacuum it out while it was empty? You can run it off a temporary tank to see if it keeps running normally, then you'll be pretty sure something is blocking the pickup tube in the tank. Or pressurize the tank with a couple PSI of air pressure and see if that will make the hose leak diesel, or take the hose off and test it under water with higher air pressure.

16. I'll try running off a spare tank. If it runs then I'll replace the the pickup. I'll just replace the line from tank to primer bulb just in case. Will regular fuel line from an auto parts place work or do I need different line for diesel fuel? Thanks

17. 

    Delmer Senior Member

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    Any line for gas should work for diesel as far as I know.

    My guess is the pickup is plugging with something that's causing the line to suck air. I wouldn't replace the pickup again without further testing that narrows it down to the pickup.

18. Honestly if the battery is 5 years or older, I'd just replace it. They are perishable items. If you get 4+ years out of a battery you're doing good. I still would have the charging system checked regardless. No sense trashing a brand new battery because the alternator is on its way out.

19. It turns out it was the fuel line. Replaced it and it running again. Thanks for all the help. I put the battery back in it, it tested good. The glow plug relays seems to be a problem. I get the error light and when I went to take it out the relais was hot to the touch. Getting a new one today. Hanks everybody for all the help.

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Source: https://www.heavyequipmentforums.com/threads/773g-will-not-stay-running.66181/

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