92 KW 3406 3ZJ issues

I've got a new to me 92 Kenworth c500 with a 3406 3zj09501 425hp. The previous owner had an inframe done, currently about 200 hours on it, IPD 15.2 pistons according to the kit number. It's had 6 reman cat OR3587 injectors, one replaced under warranty already. Still seems low on power, not as smooth as I'd expect. Makes 25-27psi boost. Can't get the pyro above 750. Governor was supposedly rebuilt during the inframe. I've maxed the afrc, and turned the screws on the pump out 5 turns. Hasn't made much difference. Just a hint of smoke on the shift and immediately clears up. Added a fuel pressure gauge and found I could draw it down to 20 psi, I added an electric fass pump to supply the mechanical as a test, now 55-60 at idle and always above 40, zero change in performance.

Plan now is to pull all 6 nozzles and get them tested and replace them as a set of any fail with something other than cat. Then inspect timing advance. I suspect a possible issue with barrels and plungers? Waiting on the tool to remove.

I guess my question is if I'm on the right track, and if there are other things I should do. Ive been around a few older 3406b and this is definitely the weakest I've seen.

Ive tried to do as much reading as I could but just need some direction. Reading all posts from guys that seemed to live and breathe these old motors gives me hope. As long as they are still around and active.

 

It didn't have any oil when I pulled the cover,.I was gonna get a new one just because. I've read a few posts about a different governor spring and spacer too so I wanted to try that. It won't rev past 2k in gear.

 

Finally got my parts in from Cat, and some other projects done.

Got a 8m9141 governor spring and extra washer, gonna pull plungers and barrels and inspect, from all the reading I've done I should lap them, or should a guy just replace all 6. How does a person tell when they should be replaced?

One thing I've noticed which isn't scientific, when I touch each injector line, they all pulse with different strength I guess, a couple really hit but some are barely there. I've kinda went down the rabbit hole reading and trying to learn what's going on in there, I think it points to plunger and barrels either weak or leaking, or possibly a pump cam going flat.

Sound like I'm on the right track?

 

Thanks for the heads up, I've been reading about it for weeks and found a few excellent videos on it. I feel pretty comfortable but I was gonna have a kill board ready regardless.

 

Thanks @wore out. I was hoping you were still active on here. Any advice or experience is greatly appreciated, I'm trying to soak up as much knowledge as I can. I plan on keeping this truck around for a long time if I can get it to perform better and I'll be the guy working on it. Hard to find people that know anything about or want to work on these old girls. I'm in Alberta and there hasn't been any places I've talked to that inspired any confidence.

Im 90% sure I'm gonna put a different set of nozzles in it. Heard too many terrible stories of the Cat remans failing quickly. I've had one go out already with under 100hrs on it and I don't think it's worth the risk. Is there a different nozzle that would be better for me? I have an OR-6689 turbo on there now.

Thanks
Zac

 

Ive got the nozzles out and sent off to get tested, found a shop that has some seemingly knowledgable older guys at it, and has the meter timing tool for when I get it back assembled.

Is there a different nozzle I can use to get a bump in power?

@wore out where do you suspect my power loss problems are at if not in the pump?

Thanks
Zac