Fuel injector adjustment

Hi Jerry, welcome.

Calibrating injectors is an easy task.

Just follow these simple instructions.

Personally, I'd just take them to a diesel shop, or

you can pick up one of these used for around $8,000.00.

Curious what you percieve to be fuel problems. What were your symptoms prior to your attempted repair?

Hello Jerry, I have the same equipment as you and had a bad injector that caused alot of white smoke while the engine was running due to unburned fuel. I don't think the injector is really meant to be adjusted in the field.

I had a more recent problem that had the same symptoms that you describe. The tractor would idle fine with no smoke but when I tried to increase engine RPM or just move the tractor under idle in a low gear, the engine would quit. I found that I could pump the primer on the side of the injector pump and get the engine RPM's to normal but it would only run at high RPM for about 5 seconds. I could keep it there by continually pumping the primer. I concluded there must be a problem with the primer. So, I replaced the primer and that took care of my problem. That's just my experience. I think we need to know a little more about your situation and symptoms to get a good diagnosis. Thanks.

Hi ,

since yesterday I have the same problem ,at low rpm my 43 hours 2011 JM 254 tractor makes a lot of white smoke who smells unburned fuel and seems to have a little lack of power ,at higher rpm it makes black smoke with white puffs every 10 seconds ,no knocking noises 

Plesae help me if someone know

Stephan

Hi Stephan,

Assuming your air cleaner is ok, it sounds like you have an over-fueling issue caused by sticking/dirty fuel injectors, and possibly fuel injection pumps. Once the problem has come this far there is nothing that preventive maintenance steps can do to eliminate it, like changing fuel filters, etc. You can try running some Diesel Kleen or equivalent through the fuel system – it may or may not help you.

Since fuel injectors for these engines are so inexpensive, it may not be economically feasible to have them cleaned. Just replace them. Don't forget to order the copper sealing washers too.

I cannot over-emphasize how important it is to have clean bug-free fuel.

Thanks Bob,

I will try Diesel clean and replace fuel filter ,hope it will be OK

If it not works ,how to know what injector are concerned ? ,in the past i got a similar problem on another Jinma 254 and somebody on this forum ( maybe you ) told me the temperature of the bad injector will be different if you touch with finger ,at that time the engine has a hard knocking sound .

All 3 injectors seems to have same temperature and no knocking sound

Thanks

Stephan  

Jerry, you need to buy new injectors from your favorite dealer. If you can find an injector shop that will clean and calibrate your old injectors for about the same as new ones cost then have that done and keep them as spares.

Stephan,

I had a problem with a bad injector on my FP 2430(JM304). I was getting white smoke and loss of power. I had to pull all injectors and inspect the tip of each. One of the three injectors was wet with fuel and more black in color while the other two were dry and grey in color. I replace the wet black injector and that fixed the problem. This may help you identify the bad one(assuming it's there is only one bad). Good Luck.

Ray

Injectors sticking is a common problem on many different engines. The easist way to determine, which injector is at fault is to loosen one line at a time with engine idling. As you loosen and then tighten each line, you will hear the engine sound different. If there is no difference, that is the bad injector.

Remove bad injector and replace the tip. You will probably find the center spindle in the tip stuck solid. It should be free and fall out on it's own weight.

The injector should then be tested on a pop tester. Any good diesel shop will have this machine. Pressure setting is 2900 PSI. This is for the 390 or 395 engines. It is set by the adjusting screw on top of injector.

Alway clean hole and replace copper washer in head.

Good Luck,

RayH

RayH wrote:

“As you loosen and then tighten each line, you will hear the engine sound different. If there is no difference, that is the bad injector.”

This is not always the case. You could have a dribbling injector that otherwise appears to perform normally. This issue usually manifests itself during startup with or without tattletale exhaust smoke, and can also be detected on a pyrometer or by checking firing pressures.

“Remove bad injector and replace the tip.”

Replace it with what? Wasn't aware that individual components were available for these injectors, particularly on the retail level. Are they interchangeable with another brand/type?

“You will probably find the center spindle in the tip stuck solid.”

What is a spindle in an injector?

“It is set by the adjusting screw on top of injector.”

Where is this screw?

And for the record, it is not my intention to diminish the value of your contribution, but to just qualify accuracy and ask a couple of legitimate questions.

Injectors and fuel pumps for diesel engines are not something for anyone but a skilled fuel systems mechanic to try to repair. There is no way to ” clean and field adjust” an injector. There are no replacement parts for our injectors or fuel pumps, all we can do is replace them with new. The only way to set injectors and fuel pumps is with the correct test stands and calibration charts.

Since RayH appears to be a dealer, it makes me curious about his assertions.

Hi everybody,

I have removed all three injectors and all have the same shape ,black dust whitout any wet spot , but a little needle point are showing in the center ,none on the brand new injector I bought to replace the bad one , is it normal ?

Stephan

That little “needle point” is the spray orifice. If you look very closely you will see four or five very small holes in it. Are you saying the new injectors don't have this? The black carbon “dust” is kinda normal but suggests that the engine is running on the cool side.

You can clean off the carbon with paint thinner or diesel fuel and a BRASS wire brush GENTLY. Do NOT use a steel wire brush because it can destroy the spray pattern.

in all my days of injectors i not seen or heard of adjusting.

it sounds like to me the fuel pump is pulling in air.

if i was to look at injectors, i would deffo not pull them apart as they dont take much dirt to block them.

if it is a faulty injector then you can renozzle it but the calibration is the tough bit. sometimes you can away just fitting nozzle but would you risk it knowing that a injector thats not working correct will harm your engine.

if your gonna take it out, wrap it to keep clean, send it off to be tested.

that way you know where you stand for sure and not waste time looking at something thats not wrong.

its not that expensive to get nozzles fitted in injectors.

leaving a bad injector that sprays to much is bad and expensive as it washes all your lubrication away, the piston now is in a dry cylinder going up and down, the cylinder half way down goes huge until you hear a knock, thats the piston slap.