3320 Stops running

[barrest]

Zetor 3320. 1991 year
Runs for about 20 mins then just quits. Release the bleed nipple and crank and she starts, runs 10-15 mins and quits again. I’ve replace the pump, both fuel filters and all rubber fuel lines. I’m not a diesel mechanic.
Any ideas??

 

[Wagtail]

G'day Mate. Have you put an inspection camera down into the fuel tank to look for any 'crud' (biological growth or debris) that would be blocking or restricting fuel getting to the system?

 

[barrest]

I ran a hose from the filler neck of the tank direct to the filter inlet bypassing the tank feed pipes. Same result, 20 mins of running then quits, bleed the system and it runs for 15-20 mins then quits again.

 

[Wagtail]

Hmmm... well 'something' is blocking, what I suspect, is fuel continuing to reach the injectors. I mean, the whole system 'works' for 15-20 minutes and there's only 3 things that you need for ignition = fuel, air, and spark. If it 'works' for 15-20 minutes there must be sufficient air & spark (compression) for it to operate... that leaves fuel, which sounds like there's enough fuel after 'pausing' for some sort of 'reservoir' of fuel to gather which isn't being regenerated.

Sorry, but someone else is going to have to join the thread to offer an alternative solution.

 

[barrest]

Thanks for your input

 

[K5lwq]

Is the pump you replaced a lift pump? Is it electric or mechanical?

 

[barrest]

It’s mechanical and bolts to the injector pump. Would an electric pump delivering fuel to the injector pump directly, bypassing all the filters work and if so what psi and volume would it need to be? The return line for unused fuel would remain connected. I need to have the filters I know but I need it to run for more than a few minutes to eliminate the injector pump.

 

[K5lwq]

I would not bypass the filters. But I would get a cheap electric pump and put it between the tank and filters to feed the lift pump. At least for a test. Something like this should work.

https://www.amazon.com/Electric-Universal-Pressure-Transfer-Carburetor/dp/B08PY7V2MM/ref=asc_df_B08PY7V2MM/?tag=hyprod-20&linkCode=df0&hvadid=505275470316&hvpos=&hvnetw=g&hvrand=12760362955183704959&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1026339&hvtargid=pla-1196911746648&psc=1

 

[barrest]

I’ll give it a try. I have a spare pump in the barn

 

[barrest]

Should there be foam/small bubbles in the glass bowl on the primary filter?