Got another one! Project: PolarXJ

[xj_man_646]

I can't recall that far back...did you do any fueling upgrades to support that turbo?

[6DoF]

yup!

running 11psi into the injection pump vs letting it draw for itself, plus i went from 0.190 injectors to 0.260's

right now trying to dial in the fueling is what's giving him trouble, like there's too much or something

[6DoF]

so i was getting mad at the XJ for being a little jerk ... i couldn't get a decent datalog cuz it would go into limp mode on the highway occasionally, but never just around. well yesterday i got mad and started beating it like it owed me money up n down the freeway. got it hot, countless cycles of mid RPM coast to full boost back n forth, up and down gears. well something cleaned up or broke loose! could be i blew out some carbon buildup, broke in the new injectors, unstuck something from it sitting so long, who knows.

it runs noticeably smoother and i'll see about limp mode this afternoon when i go for a basic drive. cross your fingers for me we're on the up-n-up now!

[xj_man_646]

Did you pull the intake and give that a good cleaning before the transplant?

[6DoF]

Originally Posted by xj_man_646

Did you pull the intake and give that a good cleaning before the transplant?

i did! but maybe not as detailed as it could have been cuz i was hoping to get a "better" intake.

on the other hand, i also tried to clean out the head as best i could too. i wonder if i had some buildup get stuck to a valve and keep it from seating fully ... finally cooked it off with the 1350deg EGT pull i did.

[xj_man_646]

Sounds plausible for sure. Gotta blow out the carbon every once in awhile.

[6DoF]

he's still convinced that my "new" turbo has sticky vanes from the logs ... and i can't disagree. i'll have to take it apart and clean everything out really well. maybe i can find a rebuild kit while i'm in there

[xj_man_646]

What did that turbo come from? I didn't realize it was VGT.

[6DoF]

VNT-17 from an 04-05 Passat. bigger and more efficient than the old VNT-15 i had. plus it's a totally different location that's higher and more forward ... gave me more clearance for better engine mounts.

VNT is the VW name for VGT

[xj_man_646]

Ahhh. Interesting. I wonder how the ECU software is different between the two engine models. Could be something with that, but I'm also assuming you weren't the first one to attempt such a swap and the subsequent tuning.

[nblehm]

I’ve work on a tdi where the intake was basically packed solid with carbon build up. That was an interesting find.

[xj_man_646]

Yep it is quite common in the TDI world, I assume due to heavier EGR usage than other diesel applications. The diesel soot and oil material that forms due to crank case vent and EGR in diesels is nasty stuff.

[6DoF]

whoever thought it was a good idea to put EGR and a crappy PCV on a smokey diesel was a doooooouuuuccchhe. lets just mist the intake with oil and carbon dust, that'll work great!

[6DoF]

you can kinda see in this pic what my intake was to start with ... i cleaned it like 3/4-ass'd

[6DoF]

so i asked the tuner to take my original Malone Stage-3 tune and just scale only the fueling for my larger injectors. even down 5psi peak boost from his prior tune, i'm probably 2x the power n torque now!

everything is better across the board. power comes in sooner, harder, has more, and then pulls longer. starts better, lower EGT's across the board ... and he's still arguing that Malone doesn't know what they are doing. now, he's got some theories and wants me to try another tune. it's entirely possible if he figures something out that his tune could be better MPG and maybe idle a tiny bit smoother, but i don't see any possible that i gain power anywhere. he's a super nice guy and has helped a ton by finding other issues i had too. he totally deserves the help when he wants to learn what's up.

now i want to figure out what program he's using to write the tune ... i have everything else now to tune any engine.

[6DoF]

#towrig

[wrath]

Is there a trailer underneath it or are you hillbilly like me and just lag bolt a tongue to the building and deck screw the axle to the building?

[6DoF]

-4 2x4's scabbed together for a tongue
-2 trailer stub axles welded to plates and bolted to the bottom of the shed.

i build the set-up before we build the house to move and use this shed then, but now it's in the way again, so i just jacked it back up and threw tires back on it. if you notice, they are the OE XJ wheels n tires bolted on backwards for better spacing

[Cobound]

Tiny home tow rig