38r might be toast, looking at KC center section

psduser1 · Nov 7, 2020

Big Bore said:
Yea, theres no haze at all, even at startup now that I'm at sea level and warm climate. I have Swamps 170/30's with about 100k on them, I think, I left the service records in CO so cant check. Truck is at 187k currently. I just don't see any indicators that there's an injector problem.

Here's a question, can/does the computer compensate for the extra "fuel" from all that oil? By that I mean would it adjust how much fuel is being injected thus preventing a haze from the extra oil coming in the intake?

No, the computer doesn't compensate for "extra" fuel.

Petro said:
Not that I've noticed. In 10 years of working on these engines, I've only ran into it a handful of times. Like was mentioned previously, I would think it would be leaving a nice blue trail of smoke if it was the turbo. The thing about the injectors issue that I find the most strange, is they act almost perfectly normal. No weird smoke, start fine and look good on a scanner. Its very strange, and if I hadn't seen it with my own eyes on several different occasions, I wouldn't believe it myself. I wish I had a better understanding of the inner workings of the injectors to help understand how this can happen. Better just be safe and swap in some 250/200s and an S468 T4 kit to be safe, its the only way to really know for sure.

Dont be shy, 300/200s, and compounds.

No really, that would be a snotty tow rig, lol.
All bs aside, I've ran a 38r with 100% nozzles for several years-around 200k miles on two trucks, and while the garret charger is an excellent setup, there is definitely room for improvement, and kc offers that. How well it actually does, no idea. For the money, itll be my next try, since the truck it's going on is a dedicated tow rig.

fastersteve said:
Your 7.3 doesn't have an O2 sensor like a gas engine, so no way to monitor mixture much less a way to compensate it. Diesels are not as mixture sensitive as gas engines, so the PCM injects (this much) fuel following (these) parameters.

As above. The computer gives no f**** about the tailpipe.

KBMKVIII · Nov 7, 2020

I have heard many great reviews about KC turbos.
I would not hesitate to give them a try especially if just replacing the center section.

Big Bore · Nov 7, 2020

psduser1 said:
Dont be shy, 300/200s, and compounds.

No really, that would be a snotty tow rig, lol.

I've always liked compounds. Never found a clean way I liked to do the atmo.

Petro · Nov 8, 2020

Big Bore said:
My wife hates that idea. So I won't show her.

Did you try new o rings first on those injectors you mention before replacing them? I just don't see how they could pass that much oil internally and it not show a symptom other than oil consumption. I would think it would definitely show in duty cycle.

On the last set I want to say the o rings were in very good shape when the injectors were removed. Ive never seen a set bad injector o ring that didn't cause either a hard start problem or that didn't push motor oil into the diesel fuel, where it was seen in the fuel filter.

Big Bore · Nov 8, 2020

Petro said:
On the last set I want to say the o rings were in very good shape when the injectors were removed. Ive never seen a set bad injector o ring that didn't cause either a hard start problem or that didn't push motor oil into the diesel fuel, where it was seen in the fuel filter.

If the injector was internally consuming oil somehow, it would have to go into the fuel and would show in the filter. Otherwise, where is it going? If it was just being returned to the oil system, it wouldn't be a consumption issue.

Petro · Nov 8, 2020

Big Bore said:
If the injector was internally consuming oil somehow, it would have to go into the fuel and would show in the filter. Otherwise, where is it going? If it was just being returned to the oil system, it wouldn't be a consumption issue.

Look I'm not saying this is for sure your issue, I'm just telling you it is a possibility because I have seen it myself more than once. I know its also happened to others because I've read about it on multiple occasions. Do what you want with the info.

Big Bore · Nov 8, 2020

Petro said:
Look I'm not saying this is for sure your issue, I'm just telling you it is a possibility because I have seen it myself more than once. I know its also happened to others because I've read about it on multiple occasions. Do what you want with the info.

I know you're not saying it's my issue, I'm really not trying to have a pissing match here. I'm just asking a logical question to see if I'm missing something, or if you are, or both, and making sure I'm understanding where your line of thinking is going. I appreciate the input very much. I've been working on these things in 2 trucks for almost 20 years, including building an engine, and I am still baffled by some of the issues they will have.

Petro · Nov 8, 2020

Big Bore said:
I know you're not saying it's my issue, I'm really not trying to have a pissing match here. I'm just asking a logical question to see if I'm missing something, or if you are, or both, and making sure I'm understanding where your line of thinking is going. I appreciate the input very much. I've been working on these things in 2 trucks for almost 20 years, including building an engine, and I am still baffled by some of the issues they will have.

I wish I was more familiar with the inner workings of the injectors. I was under the impression, that some how oil was basically getting injected into the combustion chamber. Im also not 100% positive on how its possible. Im not working on pickups full time anymore, I bought a Peterbilt and bull rack and have been over the road for the last couple years so I'm not nearly as sharp as I used to be. Just got burned out pulling wrenches everyday of my life. But you're right, even when I was doing it daily, there were several that were a complete mind f*ck. They are definitely unique.