Hey Y'all, new member here and I'm desperate to find an answer on this. I have been searching the internet for weeks trying to figure this out. Long story short I "rebuilt" a gen 3 5.3 that had gotten water in it. I honed the cylinders and installed all new bearings, gaskets, rings, etc.. This is a 7875 turbo, DEKA 80's, sloppy copy build. I'm also trying to learn tuning as well. So i get the truck running, seems to run good. Keep tuning on the truck, its going ok. Change the oil and it smells of fuel. I had a rich tune at that time, I fixed that and drove the truck a little bit (100 miles), checked the oil and its smells of fuel on the stick. Drain the oil and its dark and smells strongly of fuel. So I thought i messed up on the build and rings didn't seat or something. I let the fuel rail with injectors hang for two days to see if they were leaking, nothing leaked. So i was convinced I messed up on the build. I pull a junk yard 5.3 and install that in my truck with the same turbo, injectors, and cam setup (ss2). Truck runs good, changed the oil after maybe 200 miles to flush out whatever junkyard stuff maybe in there, and guess what, it looks and smell identical to the other motor. dark and smells heavily of fuel. I feel like it has to be the tune. I entered the injector data into my tune. I feel like the injector timing is off or something I really don't know at this point. Like I said I'm learning HPtuners and it easily could be something so easy and I look like a moron. Thanks for any and all help.

 

What is the AFR at idle and cruising?

 

It varies because im still trying to dial in the ve table. But between 13.5 to 15 idle and cruise. Thank you for the reply. I can attach a log file.

 

recent log from today

 

Pull your spark plugs and lay them out in order. Compare them to see if one or 2 look darker color than the others.

 

will do tomorrow if rain holds off, thank you

 

What fuel pressure are you running though?

If my memory is right those Deka 80's are rated at 43.5psi, so if you are running 58psi that would incorrect. Also are you running a return or returnless fuel system, because that matters in how the flow rate is setup too. I've never used Deka injectors because they are so many better options out there is proven data sheets that have 100% correct data for HP Tuners.

Cut your minimum fuel milligrams in half or more as well, that will help with rich idling and won't cause you to remove a ton of fuel from the VE table.

Get a wideband working and start logging the commanded AFR vs the actual AFR to tune the VE table.

 

I am running stock truck intake with a return style rail and stock fuel pressure regulator. I have a wideband and am logging afr error. I realize now there are better options out there for injectors, at the time I thought these were going to be fine. This is my first build, first ls swap, first turbo build so I'm learning some things the hard way. I will cut the minimum fuel like you said. Also its right around 58 psi at idle.

 

So the second engine you didn't even opened it up and it's doing the same?

I'm not familiar at all with tuning, but how could that be causing fuel to get into crankcase? Too rich condition under certain conditions?

What about other things like pcv tube sucking fuel vapors from the intake? But not too likely because crankcase shouldn't be under vacuum, right? 🤔

 

I put a cam in the new engine and valve springs. I did not pull the heads. breathers on valve covers vent to atmosphere. I thought maybe the tune had something to do with it as far spraying too much at some point. I am at a loss here. I don't want to wreck these bearings...