Changing my injectors.New ones ready to use out of the box???

[knightrider955]

I decided to put new injectors on my diesel tractor. I was wondering if I need to have the new ones adjusted or do I just put them on and Im good? Im not a diesel mechanic. The new ones came filled with some kind of oil. Im hoping my tractor will run a little better. It sounds like its got a slight miss. It smokes a little too unless I rev it up to operating RPM,then it clears up. Im hoping these new injectors will do the trick even though Ive been using my tractor in its current condition without any problems.

 

[nspec]

I would think the little injectors in our small tractors should be bench tested and calibrated ready to go out of the box. I've seen large ones for much larger engines that failed a bench test with the customer. Not practical to retest these small ones. I'd put 'em in and go.

 

[Raspy]

If you seem to have a miss at low speed light load, and a bit of smoke at the same time, you might just loosen the injector lines at the injectors one at a time, with the engine idling, until you isolate the one that's the problem cylinder. It's the one that changes the least with a loose injector line. Just crack the nuts a 1/4 turn or so, one at a time and then re-tighten before doing the next.

You might also listen to it crank without starting it to see if if turns over one compression stroke easier than the rest. This is a crude compression check looking for one bad cylinder.

You might have an injector that is not atomizing properly and causing smoke at idle, but running fine under load. You might also have low compression on one cylinder causing incomplete combustion at idle and a miss.

If you suspect compression, first check your valve adjustments. If you suspect an injector, after your testing, replace that one and see if it runs better before doing the rest. But if you replace one, do them all.

If the injectors are new, they should be ready to go. But if they are used, you will need to get them tested for pop point and spray pattern. You could also do that with the old ones. On mechanical injection engines, the test is very simple and easy at a diesel shop.

 

[jonyyuma]

When I bought my injectors, i put them in and primed them up , sprayed wd40 into air cleaner and fired it off. The oil in them is okay, it was for testing and keeping down rusting. Good luck, be certain to have a good or new fuel filter ahead of them, for longivity and insurance againest contamination..

 

[knightrider955]

If you seem to have a miss at low speed light load, and a bit of smoke at the same time, you might just loosen the injector lines at the injectors one at a time, with the engine idling, until you isolate the one that's the problem cylinder. It's the one that changes the least with a loose injector line. Just crack the nuts a 1/4 turn or so, one at a time and then re-tighten before doing the next.

You might also listen to it crank without starting it to see if if turns over one compression stroke easier than the rest. This is a crude compression check looking for one bad cylinder.

You might have an injector that is not atomizing properly and causing smoke at idle, but running fine under load. You might also have low compression on one cylinder causing incomplete combustion at idle and a miss.

If you suspect compression, first check your valve adjustments. If you suspect an injector, after your testing, replace that one and see if it runs better before doing the rest. But if you replace one, do them all.

If the injectors are new, they should be ready to go. But if they are used, you will need to get them tested for pop point and spray pattern. You could also do that with the old ones. On mechanical injection engines, the test is very simple and easy at a diesel shop.

Well when I bought the tractor it had a rebuilt engine in it with receipts. It only has maybe 5 hours on it. Also theres a return line hooked to each injector and all four injectors leak at the return connection. Also one injector has diesel bubbling up around it where it goes into the head. Would that cause an issue with how it runs? The new injectors came with new seals for the return lines and for the head so I figured I would change all the injectors and see what it does with no leaks. Im just not sure if those leaks would make much of a differance in how it runs. I just wanted to make sure those injectors were ready to throw in out of the box.

 

[mf2640man]

from a DIY aproche put em all on but do not put them in spin her over stand well back and do not get in contact with atomized disel see wether they all atomize roughly the same and none have a dribble or drop afect if they look ok bung em in and you sould be of

do all of the above cross fingerd it duzent help but at least u can say you tryed everything if it duzent work

 

[knightrider955]

from a DIY aproche put em all on but do not put them in spin her over stand well back and do not get in contact with atomized disel see wether they all atomize roughly the same and none have a dribble or drop afect if they look ok bung em in and you sould be of

do all of the above cross fingerd it duzent help but at least u can say you tryed everything if it duzent work

That actually doesnt sound like a bad idea. I might have to try that.

 

[Raspy]

The return line leaks should no affect how it runs. I don't know what brand of engine or injection style you have, but most return lines just send back what bypasses internally in the injectors. No big deal there. The "bubbling up" you mentioned is a problem. If it's coming from the injector itself that could definitely be the reason for a miss at idle. The fuel would be leaking out instead of being injected and that cylinder would not fire at idle. Or, it's leaking compression there and will get steadily worse.

With only 5 hours on a rebuild and a couple of fueling problems, you need to give the engine a once over. The leaking return lines are more of an annoyance than the cause of poor running. Check your valve clearances.

I don't agree with shooting in the dark and bending your fuel supply lines around to "check" the injectors by spraying them while cranking. Or "bunging" the new ones in. They need to be torqued correctly. The kind of problems you are describing are the direct result of a casual and poor approach to engine work. Do better. Have some respect for your engine, do some careful analysis and careful wrenching. Then you'll know where you stand and will get years of good service from it.

 

[mf2640man]

The return line leaks should no affect how it runs. I don't know what brand of engine or injection style you have, but most return lines just send back what bypasses internally in the injectors.

yes from what i know and have been toled in coleg and such like the return pipe is just for the exes disel wich is syplyed by the pump this isent a problem

 

[crashz]

I'm with Raspy on this one. Please do not pull the injectors to watch the spray pattern. Atomized fuel will easily penetrate your skin and does nasty things. If the injectors are hanging from the fuel lines, there is no telling where that fuel will go, and if you are close enough to inspect the spray pattern, you are close enough to get the fuel injected into you skin.

The fuel line returns are an annoyance. But the bubbling injector may have a cracked body, which will not allow full pop pressure at low speed.

Since you have the injectors, why not try replacing that one first, button it up and see how she runs? Since these are new, I'd replace all of them, as one new injector and three old ones may throw the balance off in the injection system and each cyclinder. But its a good test to see if you "cured" your problem.