Hard starting Jinma 224 with 90 hrs

[TractorGuy1]

I have a Jinma 224 with 90 hrs and have experienced the following:

First off I like the tractor over all with the exception of the following quirks

1. Leaking hoses and valve on the ZL20 loader and boy are those metric fittings expensive once you can find them. It is almost chepaer to find a used 2 spool controller with joystick and use common fittings.

2. Blown fuses. I am so tired of replacing the 30 amp fuse. I have gone over the wiring so many times but have never found the culprit. I even changed the ignition switch to the ford style with no luck.

3. Starter issues. The starter continues to engage only when it wants to. I have taken it to a starter shop and they bench tested it and everything checked out OK. But have not changed out the selenoid. I t seems to be worse in colder weather.


The two parts I was wanting to test out were the Injectors and glow plugs. What is the correct method of determining if any are faulty as I have been experiencing harder starting lately and suspect one or both of these.

Any help is apprecited on how to test these two parts.

 

[Ranch_Hand_Supp]

There are a lot of variables to your questions....

1, Here is my fix for the ZL20 loader. I have many happy customers.

http://ranchhandsupply.com/replacementparts/zl20zl30loadervalve.html


2, Make sure the glow plug buss bar is not gounded out.

3, I think the starter needs to be taken apart, all china grease removed and cleaned, starter bendix throw adjusted, armature and brush contact inspected, re-lubed and assemble.


Ronald
Ranch Hand Supply

 

[greg_g]

Fuse problem sounds like a bad glow plug. To test them properly, they should be removed from the tractor and cleaned up - then resistance checked at room temperature. There's a field expedient shortcut though. Not as accurate, but sometimes can point to a problem plug. Can you use a digital multimeter?

And if you've got a bad glow plug, it will definitely make cold starting more difficult.

One half of the typical QD100C3 starter engagement problem is usually thick and dirty starter lube. As indicated by Ronald, nothing you can do about that ON the tractor. If you're confident about that kind of work, it's not difficult - just time consuming. Alternatively, you can take it to an auto electric shop. If neither of those options appeal to you, a Kats magnetic heater on the starter housing will thin out the grease that otherwise binds when cold.

The other half however, is again often electrical. Poor battery ground is one reason, insufficient voltage at the solenoid is another. But again, you need to be able to use a digital multimeter to check on the 2nd reason. If you can, I'll be glad to talk you through both procedures.

//greg//

 

[greg_g]

Sorry, forgot about the injector question. As with glow plugs, the most accurate method is bench testing. Alternatively, you can remove them - reconnect the fuel lines - crank the starter - observe for any abnormal spray patterns.

But the field expedient test is simply to disable them one at a time. You do that by loosening the individual hardlines that feed them. This is done with the engine running, one hardline at a time. If there is a perceptible change in the engine sound when you crack a hardline, the injector is working. How good? Well, that's what the bench test is for. But anyway - tighten the fuel line and move on to the next hardline. If/when you loosen one that does NOT cause a perceptable change in the way the engine sounds/runs - you've probably found a bad injector.

//greg//

 

[Bob Rooks]

A diesel shop shouldn't charge much to pop test these injectors.

 

[RonMar]

Sorry, forgot about the injector question. As with glow plugs, the most accurate method is bench testing. Alternatively, you can remove them - reconnect the fuel lines - crank the starter - observe for any abnormal spray patterns.

But the field expedient test is simply to disable them one at a time. You do that by loosening the individual hardlines that feed them. This is done with the engine running, one hardline at a time. If there is a perceptible change in the engine sound when you crack a hardline, the injector is working. How good? Well, that's what the bench test is for. But anyway - tighten the fuel line and move on to the next hardline. If/when you loosen one that does NOT cause a perceptable change in the way the engine sounds/runs - you've probably found a bad injector.

//greg//

You can also sometimes hear differences in the injectors using a mechanics stethescope. A solid bar touching the injector and placed against the bone behind your ear(with earplugs in) or held against the cup of ear muff type hearing protectors can also give you an idea what the injectors are sounding like. But like Greg says, this tells you nothing about what it's spray patern is like.

 

[TractorGuy1]

Thanks for the great tips. I did not know you could field test the injectors this way. I am really curious to try it this week.

One thing I forgot to mention is that I had removed the bus bar on the glow plugs , polished it and applied dielectric grease, then moved the power lead to the center plug. This did not seem to make any difference in the starting.

Greg, I would like to take you up on testing the electrical. I have a multimeter so all I need is your instructions for the meter settings and what and how to test on the tractor.

Thanks

 

[Bob Rooks]

But like Greg says, this tells you nothing about what it's spray patern is like.

Or it's release (popping) pressure, or if there's dribbling, which can lead to lube oil dilution if not corrected. That's why bench tests are done at a diesel shop. The simple tests Greg described should not be construed as the final word, and should be used only as basic diagnostic tools for minor issues.

 

[greg_g]

I had removed the bus bar on the glow plugs , polished it and applied dielectric grease, then moved the power lead to the center plug. This did not seem to make any difference in the starting.

Understandable, the two biggest glow plug problems are (a) actual bad plugs, and (b) not getting enough voltage to the bussbar.

a) This works best if the glow plugs are already at room temperature - a heated garage, if you have the luxury. Otherwise, consider performing the test on a warm engine (not running of course).

First remove the supply wire and bussbar. Then set DMM to measure resistance. It's important you use a DMM, because analogs aren't accurate enough for this test. Put one DMM lead on the negative battery post. Put the other lead on the center conductor of the glow plug. Record the reading. Do this for each glow plug. I can't give you a specific number to look for, because resistance varies with temperature. But they all should measure to within a few tenths of an ohm from each other. Let me know what the 3 readings are, and we can go from there.

b) set DMM for DC volts. Measure voltage between the + and - battery post (engine off). Move to bussbar; put the red lead on the bussbar and ground the black lead on the engine block. Turn the keyswitch to HEAT. Observe voltage, release keyswitch.

In a perfect world, the two readings should be identical. But these wiring systems are unfortunately inefficient, I've seen as low as 7.8v at the bussbar. The lower the voltage at the bussbar, the less heat you'll get out of the glow plugs. It's a fixable problem, but measure first. Yours may not need fixin'

//greg//

 

[TractorGuy1]

I was able to test the glow plugs tonight and here are the results:

1. Battery voltage 12.9 volts

2. voltage at the lead going to the bus bar (with lead removed off bus bar) 12.7 volts

3. Voltage to lead when attached to bus bar begins at 7.9 volts and rises to 9.8 volts

4. resistance of each glow plugs from firewall out 20.5, 20.4, 20.3 with the ohm scale on 20.

5. no resistance across the bus bar.


How come there is such a difference in the voltage depending on if the lead is attached to the bus bar or not. Is this a concern


Next is checking the injectors.