Injector hour life

[JS300]

Anybody have an idea on how many hours a set of injectors is good for in a 5.9 cummins? I know that is kind of a loaded question but just looking for a rule of thumb to go by. A friend of mine had the head off his D5C awhile back and thought he would have the injectors tested while he was waiting on some parts. They all tested bad on the spray test even though the dozer seemed to run fine. He ordered new ones and says he can't believe the difference in power. It just got me wondering.

 

[StanRUS]

Anybody have an idea on how many hours a set of injectors is good for in a 5.9 cummins? I know that is kind of a loaded question but just looking for a rule of thumb to go by. A friend of mine had the head off his D5C awhile back and thought he would have the injectors tested while he was waiting on some parts. They all tested bad on the spray test even though the dozer seemed to run fine. He ordered new ones and says he can't believe the difference in power. It just got me wondering.

Mechanical or Electronic? Differences in fuel filtration @ micro level.

 

[JS300]

I should have added that. Both are in a mid 90's model dozer and are mechanical injectors. His dozer had around 6,5000 hrs but engine was replaced at some point in it's life. Mine has about 4,100 hours and everything appears to be stock. Not sure on filtration. I run the fuel filters Case calls for and change them every 250-300 hours. Who know what previous owners did.

 

[DMiller]

Mechanical nozzles wear internally, springs, lapped parts as well tips foul and orifice in the tips erode. Electronic units develop coil degradation leading to declining dwell time or increased resistance where the dwell cannot be maintained for a performance level, can also see delivery tip degradation where the spray pattern is not sufficient to efficiently combust.

 

[JS300]

Maybe I should pull them next time we have a down week and have them tested. I hate to do that and run into a bunch of unexpected problems if not needed though. I've been told they can be hard to pull and have a seal washer under them that can be hard to replace.
Dozer runs good. It never black smokes and is starting to blow a little whitish blue smoke but isn't burning any oil. I really suspected the turbo oil seal but the deal with injectors got me thinking.

 

[thepumpguysc]

All you can do, is have them tested.. no REAL written intervals for replacement..
All depends on filtration.. fuel quality.. pump timing & engine "soundness"..

 

[Scrub Puller]

xxxx

 

[Scrub Puller]

xxxx

 

[Iron@Dirt]

while running a case tractor dealer shop many moons ago, found 8.3 liters self distructing because of bad injectors at around 5000 hours, we recommended replacement at about 4000 hours. most cases engine problems were not noticed by the owner. some tractors went way past that with no trouble. the ones that failed burnt a hole down the side of the piston, with much blowby. price of injectors beats the price of an overhaul big time. would put the 5.9 in about the same time frame, but that is just my .02$ we used factory remaned injectors at first but several leaked fuel externally, new injectors worked right the first time. but remaned quality changes from time to time.

 

[JS300]

Probably time to at least get them tested then. Might be best just to buy a new set and change them out and have old ones tested just for the fun of it. I ran the valves over the winter and the gaps checked good. I've been wanting to do a blowby test with a manometer but just haven't made the time. Definitely want to be proactive and not blow a motor over something that will need to be done anyway.

 

[JS300]

Well I just found out for the last few days I've been searching for these injectors with an old part #. New part # brought up some more options. Brand new aftermarket injectors are 1/2 price of Case branded. What do y'all think? Buy from dealer or go with aftermarket?

 

[thepumpguysc]

Whats the P#> I may be able to steer you in the right direction.

 

[JS300]

Old part # J919323, New part #J919343. The ones I'm looking at have a part #C1703-3412T. I've found them several places but a quick Ebay search will bring them up. Thanks for the help.

 

[Iron@Dirt]

have seen a couple of times in my life injectors test good on the stand and go to sticking or erratic operation in a hot engine. as for case or other brand injectors for a do it your self check into warranty, half price is tempting.

 

[thepumpguysc]

I just saw the post of the P#, so haven't checked prices yet.. BUT.. incase you didn't know..
Sub. a 3 for the J for Cummins #..

 

[thepumpguysc]

I just found the tips for 20.00 on ebay.. new bulk.
BUT it takes a special tool to replace them.. I have that tool..
I don't have any cores to build.. BUT.. if you could be down & send them to me?? your call..

 

[JS300]

That may be worth doing. Let me see how things go tomorrow, found out today I might have a fairly big job to start on Monday.

I talked to a buddy that's got a diesel shop and he says he hasn't had trouble out of aftermarket injectors. Let me see how tomorrow goes.

 

[JS300]

I went ahead and ordered a set of injectors ( thinking the less down time the better) because about 3 weeks worth of work came up and I got a contract to buy some land that connects to me that will need about 100 or so hours of dozer work ASAP. Well as luck would have it we blew a hose Friday, got 1.5" of rain Saturday, and operator can't work Monday. To top it off injectors aren't scheduled to show up this Friday. I guess they bringing them on horse back or something. Anyway thanks for the help and I will update on wether or not any difference was noticed.

 

[JS300]

I finally got time to tackle the injectors and ran into an issue I hope someone can help with. All 5 of the injectors I have tried to pull so far have been stuck to the hold down nut. I was able to get 3 of them free by holding the injector head with a 15mm wrench and turning the hold down nut with an offset box end wrench. Once I got the nut off the injectors actually came out easier than I thought they would. My question is how can I get the other 2 loose? I'm afraid if I just turn the hold down nut and let the injector spin it will break the locating ball off and if I'm not really careful the pieces could fall into the engine when I pull the injector. I've got them soaking in Kroil overnight but really don't think it's going to help. The injector I haven't tried yet is the hardest to get too so I'm saving it for last. On the 3 I got out once I got the hold down nut loose from the injector the nut spun out pretty easy. Please let me know what y'all think on this.

 

[inthedirt]

Make sure you dig out the square-cut o-ring around the hold down nut. It may not look like there is one, but trust me there is. With that out of the way, you get penetrating oil down between the nut and injector body. And yes, you don't want to wipe out the locating ball groove. Also, be careful. I had one do the exact same thing. While trying to "force" the nut loose, the open end of the 15mm Craftsman Professional wrench broke and shot part of the ear all the way across the shop!