Case 680K odd starting issue

[chrisdvorak]

I have an 89 case 680K backhoe with a 6 cyl cummins in it. when starting the machine it will fire right up but then instantly dies every time then you have to crank for maybe 5 seconds then will start again and run fine all day long with no issue, I assume its bleeding off fuel pressure internally but don't know where to look or how to test that theory? Ive also noticed it starts a little easier/faster if machine is parked downhill. filters are new. any ideas would be appreciated

-thanks

 

[Dave M7040]

Even in the winter?
Sounds like the fuel is evaporating out of the carb due to heat.
Could you temporarily install an outboard motor squeeze bulb to fully fill the carb before starting to confirm that is the source of the problem?
Dave M7040

 

[skyhook]

I don't think this has a carb, it's a diesel engine.
Yes it does sound like its loosing prime, check your fuel lines for leakage etc. Also check around fuel filter and around fuel tank for small leakage.

 

[chrisdvorak]

Yup no carb, i will look closely around the lines again

 

[aircommuter]

I have had trouble like that, I found that the hoses will let air through the hose and on some applications where the tank is high enough the hoses will seep through the wall. I would replace all the hoses especially the suction and return ones. It started when they changed fuel and reduced the lubricity.

 

[crazyal]

My 580k did something similar. There's a metal inline fuel filter (not the screw on filter/ water separator ones) that looks like a generic filter you would see on a garden tractor. It looks like it's two halves crimped together in the middle. The back of the filter crimp was rubbing against something and developed a very small hole. Just enough to let a little air into the system but not enough to leak a noticeable amount of diesel. It's real cheap and you should be able to pick one up almost any auto parts store.