How to clean injectors

[tnjind]

My 3 cylinder Mitsu starts hard unless the engine is warm and has white smoke while running. I believe the injectors could use some attention. Can I remove them and possibly disassemble to clean?

 

[Bavarian]

Quite likely you're having an issue withe the glow plugs and not the injectors.
In the first VW diesels, the glow plugs could only be tested when installed. Therefore we had to remove the nozzles to get a look on the plugs. But we never touched the nozzles for hard start issues.

Test your glow plug system first. Power to the plugs is the first thing to check.

 

[warment]

My dad's international 234 starts hard too. It has a Mitsubishi 3 as well. I removed the glow plugs and they all worked fine. No smoke when running on his.

 

[tnjind]

Thank you for your response, that was fast.
The glow plugs work I have to use them to get it started unless its already been running, even when its 90 outside. I have put two new glow plugs in it, I can feel them get hot. This poor tractor has seen years of neglect. It doesn't even have a water separator just an inline filter for a small engine.
I have run some cleaner in the fuel but don't have much confidence in it helping much.

 

[the old grind]

Cleaning injectors isn't DIY stuff, and there are indeed far fewer potions that can be added to the tank as with gas burners. Injector services near here get ~$50/unit, but I suggest half of the value is in just knowing if they weren't shooting equally when you took 'em out. Excess valve 'lash' can reduce compression/ignition and scavenging, both detrimental to strong running. This IS usually a quick and easy DIY.

After checking lash, another thing you might do is test compression, but once again .. car stuff won't work unless your gauge can handle the higher pressure. Remove all GPs for this and plumb your rig to each of their holes in turn. (you knew that) I hope 'white smoke' isn't from a head gasket leak that just tightens up when the engine warms, but comp test may hint at that.

btw, you might get lucky without a water separator if your filter bowl is easy to see/drain. I get water in the Case/IH's tank when tree litter plugs the drain tube of the 'spill cup' below the filler cap. Rain, cold, and siphoning from the cup will draw water into the tank. BTDT more than once. Of course, it shows up a minute of so into a warmup when 'Little Red' can't draw fuel through a filter that's encased in a block of ice.

After some heat gun work, melting the filter element out of the ice cube, and bleeding at the injector pump, I get running again. No way to ever tell how well I cleared out all the water, but I'm reassured that it settles out neatly, and that I'd see it in the bowl's glass if I looked first after a weather change. WIMI, YMMV, but after a few k hours on an oldie that still runs, a bit of water getting into the fuel line might not always be the nightmare we fear. t o g

 

[GMIslander]

I used to service a lot of fuel injectors forty years ago. You need an ultrasonic cleaner, a test bench and possibly spare parts.
You would want to replace with new or rebuilt.
Black smoke or misfire would be the indicator of poor fuel injection.

 

[tnjind]

Thanks guys, I assumed it was not a simple task. I more afraid of loosing/damaging parts that cant be sourced if I try to disassemble/clean. I need to find an aftermarket separator, any ideas for source?
I do indeed need to check valve lash and since the valve cover is leaking I had planned to do that soon. Hopefully that will help.
The old tractor is a nightmare to look at as it was in a garage fire before I got it and all plastic, wiring, three tires were gone. It actually runs descent once started although it does have high RPM miss.
I have owned this thing for several years and have been using it often the last two. I just put the FEL back on it after buying all new hydraulics (the aluminum pistons were melted in the cylinders).

Thanks again for the info and help.

 

[Bavarian]

I absolutely agree, taking injectors apart isn't necessarily a DIY.

Usually there are three things to look when bench testing an injector: leak test, injection pressure and spray pattern.

If all three of those criterias are satisfying, there is nothing inside an injector to clean. Any damage or malfunction would show up on one of the three criterias.

 

[Ilikeurtractor]

Also keep in mind it is not unusual to need to operate the glow plugs on in indirect injected diesel, even on warm days. Probably on a "good" engine with no blow-by and proper adjustments this is not required for decent warm-weather starts, but all of my Mitsubishi engines will take a lot of cranking without the glow plugs. And during that cranking the glow plugs are actually active so I wonder how much cranking it would take to get them to run with the plugs completely disconnected. White smoke is a sign of either low compression, coolant in the cylinder, or water condensation or combinations of those. Most of my tractors puff a little bit of white smoke until the engine is working hard (up to proper temp). A lot of these engines don't even come with thermostats so it can take a lot to get them up to the ideal operating temp especially on cold days.

 

[tnjind]

Well I drained the tank, it was a VERY small trickle out of the inline disposable filter. I replaced the filter and fuel, it flows much better with the new filter I had hoped it was the problem. It was not.
I adjusted the valves they were not off very much at all.
The tractor runs and it "surges" and blows black smoke when it does it. It seems worse the higher the RPM.

It also makes a loud diesel sound when it does it. Like spark knock.

I used the ole "screwdriver to the ear method and the noise really seems to come from the rear injector.
My theory is the injector is dropping fuel instead of spraying and the noise is from trying to compress a liquid (not good).

I would like to find another injector, does anyone have any idea where I can find one?