Hard starting Kukje (Branson 4220, Century C42, Zetor C42L

[UpLateAgain]

I have a Zetor C42L tractor with the Kukje (South Korean) A20000N2 four cylinder diesel engine. It is the exact same tractor as a Branson 4220 or a Century C42, just rebranded. All parts are interchangeable on all three tractors, but Zetor discontinued the line about five minutes after contracting to have the tractors built, and do not in any way support it that I can find. So I generally have to use Branson branded parts.... which (as I said) are completely interchangeable, but expensive.

Lately I have had extremely hard starting if cold.... even when the ambient temperature is in the low 60s. The tractor will crank for up to a couple of minutes (I try not to crank it more than 15 or 20 seconds at a time) before catching, the whole time producing tons of white smoke. I just replaced the glow plugs with four new ones (made no difference), and the fuel feed pump. I can't seem to get the specs on the operating pressure the fuel feed pump is supposed to maintain, but have over the years just replaced it when it has gone bad with a common 12v 4-7 PSI Diesel/petrol electric pump found on Amazon for about $20.00 and never before had a problem. I also replaced the fuel filter..... a commonly available and inexpensive item.

So I'm sort of coming down to the injector pump ($1700 plus shipping) or the injectors ($110 each plus shipping). The tractor only has about 960 hours on it and has been flawless up to this time. It doesn't use any oil, and once it starts, it doesn't at all smoke (white or black), and seems to have full power.

Any diesel mechanics out there who have seen this before and have a good idea what it might be? What's the best way to test the injectors, and what do I look for? If bad, can they typically be cleaned, or must they be replaced? I can probably rig an in-line fuel pressure tester to find out how much fuel is getting to the injectors...... but don't really have the specs on what it is supposed to be, and can't seem to find it anywhere on the Internet. I can probably order a manual for it from the Kukje, but it will take a month or so to get here from South Korea, and will cost about $400.00.

Any help in this diagnosis is appreciated.

Thanks,

Devon

 

[Kentuckyfarmer]

I think 4 to 7 lbs is enough to feed the ip. I would check and make sure that it didn't loose its prime after sitting for a while. If every thing checks out that there is fuel and you already know you have pressure I sure would start with injectors first. Any diesel shop should be able to check and see if their leaking and pop pressure and spray pattern. There have also been lots say they get parts from cummins instead of ordering thru Branson. Probably be a lot cheaper on the old pocket book. Let us know what you find out and sorry but I don't have any information or spec's on the motor or fuel system.

 

[ericm979]

The fuel injection pump is a Bosch VE, which is or was a common pump on smaller engines. It was used on small VWs among others. You should be able to get it tested or rebuilt.

Bleeding the injector lines might help.

 

[Kentuckyfarmer]

If I may ask op where did you get the glow plugs from? Mine starts fine when warm out but when it's cold it starts ruff. Spits and sputters for like 30 seconds and smokes a little until cylinders get warm the runs fine. I checked glow plugs and they all check fine but have read they came from factory with really cheap made ones. I run it thru a couple cycles for the glow plugs but it makes no difference. The 5.9 cummins in my truck the grid heater goes thru one cycle and you bearly hit the key and it runs like it was warm out.

 

[Ron50]

Check coolant level to make sure that white smoke is smoke and not water vapor.
You can use a hand held hair drier as a substitute for bad glow plugs. Best if you can remove air cleaner and blow directly into air hose while cranking. This can help ok glow plugs in really cold weather as well.
Valves might be getting a bit loose. Does it black smoke more than it used to under full load?
Timming might have slipped. Late will give you white smoke, but no fire. Low injection pressure or dirty nozzels will also produce white smoke and no fire.
Last resort can be a very, very small amount of starting fluid.
If you pull the injectors, test all cylinders for good compression. Good luck.

 

[dfkrug]

The simplest explanation for the symptoms you see, UPLATE, is no signal to the glow
plugs. That means a bad switch, wire, or glow plug controller. Have you checked to see
if you get 12V at the plugs?

 

[Texasmark]

The simplest explanation for the symptoms you see, UPLATE, is no signal to the glow
plugs. That means a bad switch, wire, or glow plug controller. Have you checked to see
if you get 12V at the plugs?

My take too. Glow plugs not illuminating. Next time you go to start, take a volt meter and check to see if they are getting voltage when the glow plug warning light is on in the instrument panel. Check back with your findings and will go from there.

 

[UpLateAgain]

The simplest explanation for the symptoms you see, UPLATE, is no signal to the glow
plugs. That means a bad switch, wire, or glow plug controller. Have you checked to see
if you get 12V at the plugs?

GOOD CALL! Thank you! Now all I have to do is find the open circuit. It hadn't occurred to me that there was no signal to the plugs because the timer on the dash is lighting up and going out after the appropriate 12 seconds..... so I just assumed there was a complete circuit without thinking it through. But obviously the ground from the plug controller doesn't rely on going through the plugs to the block.

Many thanks to those with other suggestions.... and the info on the IP and injectors provided is good to know stuff. But it is now obvious this is an open glow plug circuit. I'll start tracking it down later today.

 

[Kentuckyfarmer]

GOOD CALL! Thank you! Now all I have to do is find the open circuit. It hadn't occurred to me that there was no signal to the plugs because the timer on the dash is lighting up and going out after the appropriate 12 seconds..... so I just assumed there was a complete circuit without thinking it through. But obviously the ground from the plug controller doesn't rely on going through the plugs to the block.

Many thanks to those with other suggestions.... and the info on the IP and injectors provided is good to know stuff. But it is now obvious this is an open glow plug circuit. I'll start tracking it down later today.

Was a good call. I was assuming you checked that before you put in new ones. Reading your post I was seeing myself going thru the process I did. I'm getting voltage but still a spit and sputter starting if cold. I think I have some bad glow plugs but check them and they all ohm out close to the same. Going to pull the plugs and check them on the bench with 12 volts. You didn't say where you got yours.

 

[Dave M7040]

I am seeing many people who replace or do wiring on their GP circuit, make serious mistakes.

Some glow plugs are wired in series and some in parallel. It makes a tremendous difference.

Do you have a wiring diagram in your owners' manual which you could post?

If you are going to do your own troubleshooting you need a few inexpensive tools.

A test light

A multimeter

An infrared temperature measuring gun for less than $20 on Amazon

Amazon.com: Etekcity Lasergrip 774 Non-contact Digital Laser Infrared Thermometer Temperature Gun -58℉~ 716℉ (-5�℃ ~ 38�℃), Yellow and Black: Kitchen & Dining

Post some pictures of your glow plugs on the engine along with their wiring.

White smoke means un-burned fuel.

If you can easily do so, disconnect the air filter assembly from the intake manifold. Direct the hot air from an electric heat gun into the manifold as you crank the engine. A hair dryer will also work although not as well.

If the manifold is metal, even a propane torch can warm the intake air and help starting. Watch this youtube video to allay any concerns with the torch.

This youtube video is just to show you how engines were started before Glow Plugs became common . I am not suggesting you change your tractor but rather realized how much heat is necessary to get things firing.

The correct term is Thermostart also known as a flame heater.

HOW THE FLAME HEATER WORKS ON A PERKINS DIESEL - YouTube


Do NOT test your GP's by connecting them to 12 volts. Sudden death of the GP can be the result.

Dave M7040