Fuel System Help with Zetor 5211

[CraigPrusansky]

I am posting this on a few different forums, so if you have seen this already, please forgive the duplicate post.

I have a Zetor 5211 (1980's) that recently died in the middle of bushogging the pasture. It acted like it ran out of fuel, but it had over 1/2 a tank full. I had a mechanic come out and the fuel filter, fuel pump, and check valve were all replaced. The bowl is fine. I checked all of the hose clamps that I could see and they are all tight with no signs of leakage or air coming in. I also drained the tank and checked the pickup lines, and I saw no evidence of cracks or damage, or debris plugging them up. The fuel cap was also cleaned and I made sure that the vent holes were clear and the springs in the cap are working. When I prime the fuel system, it runs for about a minute and then dies.

The mechanic seems to have lost interest in troubleshooting any further. Is there anything else I should check, and are there any other connectors or things that should be looked at that I cannot see (hidden behind the engine, etc.)? Any assistance would be greatly appreciated.

 

[hector gemme]

My broder-law have a ZETOR and the same tink hapen and I just prime 10 shutt the small pump and he fire .

 

[Roger in Iowa]

If it has a transfer pump, sounds like it is not working since you can get it to run for a minute by priming. New pumps
can be defective!

 

[Tracy Brown]

I am not a diesel mechanic but something I have done to help find a problem is this. Find a place as close to the tank as possible and
install a low pressure electric fuel pump (4-6 psi) with a loop of clear fuel line on the exit side. Turn it on, prime your fuel system
again, start it and see how long it runs. If it runs, then you probably are getting air in the fuel system. The clear line will show bubbles
if you are getting air in before the electric pump. If you are getting air in below the pump, it should show up as a leak between the
electric pump and the inj pump. If it runs with no bubbles and no leaks, I would question the quality of the factory pump you replaced.

I have installed electric fuel pumps on several older tired diesel machines with good results that would not give good dependable service
otherwise. Yes, I know if everything is perfect, this is not necessary.

 

[David G]

Is there a solenoid in the carburetor?

 

[M-MAN]

Customer of ours years ago had a Zetor
like that. He wanted us to install a low
pressure electric pump on it. Worked
fine after that.

 

[Donald in MN]

i worked at a place that sold Zetors and a few had that problem. the head service tech. called their service department. in pennsylvania and they told
hin to put on an electric fuel pump. the head guy out their said that they were trying to figure out what caused it. it was worse in cold weather

 

[Pycoed]

Zetors with the tank below the prime pump are plagued with air leaks that cause just this problem (I have a 7045 - ask me how I know!)
The prime pump works fine for the earlier models with a tank in front of the dash.
Three cures are available:-
1 Renew every bit of hose between the tank & primer, check the metal lines for leaks, don't forget the return hose & metal line & also the one between the injection pump & the block. replace all the copper washers on the banjos too. (this is what I did)
2 Fit an electric lift pump via tank & primer/bowl (or remove primer/bowl & replace with electric & inline filter) Pump will need to supply about 10psi,
3 Fit a "Tigerloop" as installed to domestic oil boilers (furnaces in US?)where the oil tank is below the boiler pump. Essentially this is a clever design is de-aerator which reportedly completely cures the problem. Can get new for about 40 in UK or S/H half that on Ebay.
Good luck & Merry Christmas

 

[Pycoed]

PS
The bowl gasket is a common source of air leaks too - may be worth a smear of Holdtite on a new one. Don't just screw up the nut harder to fix it - fit a better gasket if you suspect that.
These air leaks can be a bugger to find- diesel doesn't always leak out where the air can get in!
It took me several goes before I got mine airtight & if it ever plays up again, I'll go straight to a Tigerloop, which seems the best solution to me, since it's specifically designed to cure this sort of problem.