Did I just have an injector stick?

BrianX128

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So my 6.9 I just got that stranded me on the highway last night I put a facet electric pump and bypassed the water separator and life was good today. No more air intrusion and ran like a dream.

On my way to run errands tonight I was going up a steep hill in third at 2800 rpms I had it wound up good. When I shifted into 4th I got a pronounced clatter that sounded like videos I've seen of a stuck injector and I had a giant and I mean giant cloud of pure black smoke behind me. Power stayed about the same.

When I got to the top of the hill and let off the throttle it went away totally. Idled normal and drove normal for another 20 minutes. Engine bay looks fine no blown off return cap or anything. What was that?
 

Thewespaul

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That’s what it sounds like, how long was it spewing black smoke? Injector hanging open will make some toasty egts
 

Thewespaul

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No unusual sounds afterwards? Should be fine then, 15 seconds is enough to get pretty hot, but these are forgiving engines.
 

BrianX128

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No it sounds totally normal. Anything suggestion wise to help not do that again? I'm for sure staying away from 2800+ rpm. Maybe a giant shot of fuel additives?
 

Thewespaul

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Sounds like you have run a good bit of atf already through it so I would step up to stanadyne performance additive, or your preference to the equivalent. Something is contaminated or not getting properly lubricated.
 

BrianX128

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I usually run the optilube xpd stuff but I haven't put any in this engine yet. It's been pure diesel so far outside of putting the atf in the fuel filter. I don't think it's helping that the truck sat for a year before it's journey home a couple days ago. I think I may have broken some crud loose in the ip with all the atf I was using to top of the fuel filter.
 

BrianX128

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Honestly I didn't notice one. I'll look again tonight when I get it back to the garage.
 

snicklas

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Trust me, if you had a melted cap, you would know. On the 88, the #7 injector has a standard through cap on it, but the PO capped he firewall side port. I happened to pop that makeshift cap off the while idling in the cul-de-sac. In less that 2 minutes, I probably pumped 2+ gallons of fuel out on the ground..... Since I was moving the truck, you could track exactly where I had driven, and the puddle that was at least 6 foot around where I stopped and was trying to figure out what had happened
 

BrianX128

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The ******* did it again on the way home. I'm attempting to upload a video on my garbage internet but it sounded like a Detroit for 20 seconds and I pulled over and let it idle for 30 seconds the sound goes away immediately when I let it idle and then it just drove home like nothing ever happened.

This truck is quickly becoming a discouraging investment. Now I believe I'm gonna be up the creek for 8 new injectors.

When I got home cylinder 7s return cap was hot. 2 and 4 were warmer then the rest but not as hot as 7. Everything else felt normal.
 

BrianX128

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It just doesn't make sense it didn't do any of this injector knock for a 2 hour drive when I bought it three days ago.

Can some sort of air intrusion from the return lines be causing the injector knock? That's gotta be it's own thing just caused by garbage injectors right.
 

Thewespaul

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I don’t see how air intrusion can cause you to billow black smoke. I’ve had injectors hang open and they get hot but don’t melt the cap down.
 

Macrobb

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I don’t see how air intrusion can cause you to billow black smoke. I’ve had injectors hang open and they get hot but don’t melt the cap down.
I've had lots of black smoke on running out of fuel along with surging - you get air in with the fuel, the engine output drops for a fraction of a second, the governor cranks the metering valve wide open to try to compensate; it then gets fuel instead of air and overfuels until the revs come up and the governor compensates again.
That being said, you would get some decent surging there too, as the IP compensates back and forth.
This is what you get with air intrusion while running.

In your case... I think you are on the right track with the injector being an issue.
You might try the ATF trick and see if it clears them up, assuming the injectors were new at one point.
(If you have a set of "remanufactured" injectors in there... you have a set of injectors each with it's own wear on it, and there is no way to balance them for long.
Injectors can easily be "remanufactured" correctly, just by replacing the nozzle and re-shimming it... but this just isn't done due to the cost of new nozzles).

I'd really recommend that you get your injectors from either R&D IDI Performance or Conestoga diesel. You can also check with Typ4 and see if he has a set.
R&Ds injectors come with new nozzles and matched pressures, and they /work/.
 
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