Cyl 7&8 Issues

HobbyStock62

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So this started this winter. Started off with my truck jelling up, it was like -10 for a week, and I was heading into work going 65, then just fell on its face and i was doing 30 until i could hit an exit, then in stalled out on me. Got it fired back up and drove it a mile or so back home and parked it. Then it warmed up, everything was fine for a couple weeks, then it started missing really bad to the point where it would stall. Cyl 7 and 8 contribution balance codes. So I put injectors in. The injector body in cyl 7 was kind of scratched up for some reason, couldnt see any issues, but thought it was strange. Runs great for two weeks, then it starts missing again. Cyl 7, so i pull the injector out, and the copper crush washer is blown off of it and o rings are burnt up. Put an injector in, again great for two weeks. Starts to miss again, this time 8. Same thing...So im really butthurt at this point and pull the cab, get all the injectors out and check the cups. The cups were pitted up at the bottom, but I couldnt see any cracks. I put a couple cups in 7 and 8 just in case. Get it all back together, runs great for about a month and now cyl 8 again...what in the actual **** guys.
OEM injectors, torqued to spec, bolt holes blown out, and the cups cleaned out before injectors stuck back in each time. Am i looking at heads now?
 

ghohouston

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Are you getting the injectors fully seated? O rings lubed good? If yes, then my guess would be you need to tighten the bolts a bit more. I have literally never used a torque wrench on a 6.0 injector (done probably north or 1,000 at this point), and never had a problem/come back from my good and tight method.
 

HobbyStock62

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Fully seated, I have done plenty of injectors as well, and never used a torque wrench, up until this happened and I figured I had to have left them loose, but I just cant believe that. And I mean this time, the cab was off and everything was 100% cleaned out and dry, ran the bolt down each hole, always lube the o-rings...I just dont get it. And I had all the injectors out to check cups, and cylinders 7 and 8 are still the only ones giving me issues.
 

6.0 Tech

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Is it possibly an electrical issue this time? Have you pulled the injector to see if it is the copper washer that failed again?
 

HobbyStock62

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I am going to pull the injector this afternoon if we slow down some or tomorrow. Webb, do you think the bolt would have stretched some?
 

HobbyStock62

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I got the injector out, the copper washer is perfect, but the body of the injector that sits in the cup is all black and the white o-ring was starting to get burned up. So I would think that the head has to be cracked, compression is coming up around the cup, and torching the o-ring? I can text a picture of the injectors if wanted, not smart enough to put them on here.
 

webb06

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I got the injector out, the copper washer is perfect, but the body of the injector that sits in the cup is all black and the white o-ring was starting to get burned up. So I would think that the head has to be cracked, compression is coming up around the cup, and torching the o-ring? I can text a picture of the injectors if wanted, not smart enough to put them on here.



You replaced 7&8 cups right? Did you apply loctite when installing?


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HobbyStock62

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Im just at a loss here, I put new o-rings and washer on the injector, checked the cup and hole (as good as you can with the head in the truck) didnt see any issues, replaced the injector hold down and bolt and its now a constant miss in 8, from the second I started it. Checked the FICM, and injector harness, all is good there. I dont want to say it, but I think I got to pull the head. I mean, I dont know what the next step other than that would be?
 

webb06

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Im just at a loss here, I put new o-rings and washer on the injector, checked the cup and hole (as good as you can with the head in the truck) didnt see any issues, replaced the injector hold down and bolt and its now a constant miss in 8, from the second I started it. Checked the FICM, and injector harness, all is good there. I dont want to say it, but I think I got to pull the head. I mean, I dont know what the next step other than that would be?



Do you have a way to check compression on 8 first? To rule out anything electrical


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