Injector removal problem

Sfath · Feb 23, 2023

Hi All,

I got a small Mitsubishi MT372 tractor with the KE70 engine and I'm having trouble removing the injectors for cleaning. The manual says to remove the injector pipe from the nozzle and then remove the mounting bolts from nozzle. It then says to tap nozzle gently with piece of wood to loosen it and this is where I am at. I'm scared that if I tap it any harder I might do damage. It won't budge and now I am wondering if perhaps the nozzle needs to be unscrewed. I don't know if I am missing something here. Does anyone know about the KE70 engine that could help? Below is the photo of whats written in the manual and then photos of my engine with the mounting bolts in and then out.

Sfath

rustred · Feb 24, 2023

Is there a real reason u are removing them. If its just to
clean them leave them alone and add a conditioner, like
howes for example. Explain your cleaning . This is a job
for qualified personal.

Dieseltech · Feb 24, 2023

Injectors WILL be stuck in the head IF the compression sealing washer didn't seal, and then allowed carbon/soot to build up BETWEEN the injector body and cylinder head
bore. If the engine was starting/running OK put the hold down bolts back in and run it. If not running OK, twist/lift injectors to get them out of the head for repair and
testing.

showcrop · Feb 24, 2023

Some Ford model(s) call for a special tool, (pry bar) to pry them straight up. BUT, only if they really need to come out.

Sfath · Feb 24, 2023

(quoted from post at 23:11:36 02/23/23) Is there a real reason u are removing them. If its just to
clean them leave them alone and add a conditioner, like
howes for example. Explain your cleaning . This is a job
for qualified personal.

Hi,

the tractor idles ok but runs very rough when the revs are increased. Almost like it is running on one cylinder. It also won't rev to around 2700 but to about 2200. I bleed air from fuel system, changed fuel filter, adjusted valve clearances and the problem is still there. I now suspect it may be a half blocked injector. I tested them by cracking the fuel line on both injectors and found the engine revs died down so it cannot be a fully blocked injector but only partially. That's what I am guessing anyway.

Sfath · Feb 24, 2023

(quoted from post at 06:01:34 02/24/23) If not running OK, twist/lift injectors to get them out of the head for repair and
testing.

This seems like what I needed to do but will wait for Rustred's reply before continuing. His response got me bit worried now. I thought removing and cleaning the injector was job lay person can do?

Dieseltech · Feb 24, 2023

Single hole injectors won't get partially blocked like that, direct injected engines with multi holes can and that will cause more smoke and low power. I'd still suspect
fuel supply TO the injection pump with what you describe. I'd start at the tank and see how the fuel flow is there into a catch can for four/five minutes. SOMETIMES flow
starts out well, then slows to a trickle that won't show up with a 10/15 second flow test.

Sfath · Feb 24, 2023

(quoted from post at 19:15:21 02/24/23) Single hole injectors won't get partially blocked like that, direct injected engines with multi holes can and that will cause more smoke and low power. I'd still suspect
fuel supply TO the injection pump with what you describe. I'd start at the tank and see how the fuel flow is there into a catch can for four/five minutes. SOMETIMES flow
starts out well, then slows to a trickle that won't show up with a 10/15 second flow test.

Are my injectors single hole or multi? If they are single then I may not bother pulling injectors out if there's little chance single ones could be blocked.

That test sounds like a good idea but I'm not sure how to do it without the engine running? I also don't know how much fuel it should be?

Is there a chance it could also be the injector pump at fault? I'm starting to get little worried now as I was convinced before it was just a blocked injector problem.

rustred · Feb 24, 2023

My internet was down this morning. From what u are
saying it appears like fuel or the pump. Diesel tech has u
covered.

Sfath · Feb 24, 2023

(quoted from post at 20:45:36 02/24/23) My internet was down this morning. From what u are
saying it appears like fuel or the pump. Diesel tech has u
covered.

I'm hoping it's not the pump because that would be expensive. But I'm guessing it should not be a faulty pump because the tractor has only about 300 hours on it. Below is a recent photo of it.

showcrop · Feb 25, 2023

(quoted from post at 21:26:40 02/24/23)

(quoted from post at 20:45:36 02/24/23) My internet was down this morning. From what u are
saying it appears like fuel or the pump. Diesel tech has u
covered.

Click to expand...

I'm hoping it's not the pump because that would be expensive. But I'm guessing it should not be a faulty pump because the tractor has only about 300 hours on it. Below is a recent photo of it.

Pretty tractor! When you reach 3,000 hours it may be advisable to remove the injectors for cleaning.

Fixingfarmer · Mar 1, 2023

Im assuming the hose and nut will pop off might be easier to
disconnect the fuel line at the other end where it clamps and
take it to the vise. Ive never seen a threaded fuel injector like
a spark plug but I believe this is what you have and found a
picture for you

Sfath · Mar 1, 2023

(quoted from post at 05:29:47 03/01/23) Im assuming the hose and nut will pop off might be easier to
disconnect the fuel line at the other end where it clamps and
take it to the vise. Ive never seen a threaded fuel injector like
a spark plug but I believe this is what you have and found a
picture for you
<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto148734.png>

Thanks for that! I'm going to first try Diesel tech's advice about a blockage in the fuel system (before the injector) somewhere being the problem. If that is not the problem then I will pull the injectors out to see if that's the problem. I will leave pulling injectors out as a last resort. I just need to find the time to do it. Hopefully a day next week sometime.

Injector removal problem

Sfath

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rustred

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Dieseltech

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showcrop

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Sfath

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Sfath

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Dieseltech

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Sfath

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rustred

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Sfath

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showcrop

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Fixingfarmer

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Sfath

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