Project: PolarXJ (M-TDI XJ)

6_DoF

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Sep 23, 2022
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Black n Gold Territory
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1.9 ALH XJ
well, he's already found issues with my jeep after seeing some logs ... told me the vanes were sticky or the vacuum sucked. sure enough, the brake booster was leaking just enough to effect it!
 

6_DoF

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Joined
Sep 23, 2022
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Black n Gold Territory
TDI
1.9 ALH XJ
you ever get to a point where something is just not right ... you just get pissed off at your junk and start beating it like a rental with the extra coverage?

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!
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
would not surprise me if vanes were a bit sticky. smoky crappy tunes can definitely do a good bit of sooting up in there. and even if the vanes seem to move well enough, i'm fairly certain they can still get sticky under boost/load because of the little bit of free play in there, could possibly cause vanes to be "pushed out" to one side and be more susceptible to binding on hardened soot chunks on the machined surfaces. and with it vacuum actuated it doesn't always take that much of a hangup to cause it to "stick". just my theory. hopefully it's just a matter of perhaps another minor hardware "issue" or two (or maybe even none) + just the right tweaks in the tune to get the fueling (and thus timing, boost) right on :)
 

J_dude

Veteran Member
Joined
Jan 9, 2020
Location
SK Canada
TDI
2003 1.9l “Jedi”
you ever get to a point where something is just not right ... you just get pissed off at your junk and start beating it like a rental with the extra coverage?

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!
I think they call that the good old Italian tune-up 😁
 

6_DoF

Veteran Member
Joined
Sep 23, 2022
Location
Black n Gold Territory
TDI
1.9 ALH XJ
finding some oddities and unexpected operation between my engine and Mr. Burpod's. Mine is requiring a good bit more timing than he expected. Mine responded well to the more advanced timing of the Malone tune, where his hates it. similar physical timing per VCDS, only real difference is his cam that we know of so far. hopefully we can sort it out for easier tuning for anyone else who might end up similar later.

right now my old tune only modified to account for the big injectors runs quite a bit better than what he was shooting for with me ... and i know it's KILLING him to know why :lol:

his tune idled smoother though

new trials to hopefully run this weekend ... stay tuned.
 

dieseldonato

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Joined
Mar 10, 2023
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Us
TDI
2001 jetta
Different applications dictate different tunes. You're moving a heavier vehicle, so the tune will need tweaked accordingly. Just like with my car, seems to require very low n75 values to make boost. He's (burpod) has mentioned it several times, that it's an oddity, since my set up is very similar to others he's tuned. 🤷 it happens. I've been playing with timing in adaption settings (on burpods reccomendation.) I'd assume you could do the same and nite your results. May help him to get it dialed in better/faster. For example (0 is where burpods tune is set.) -50 made the egts higher, and +2k rpm (2.5k really) got hotter yet. But the bottom end sub 2k rpm was great. +50 sub 2k rpm was decent, but noted it felt a little sluggish. +2-2.5k rpm responded better. +100 noticeable loss of low rpm power, but egts were lower and power over 2.5k rpm seemed to increase. I think that was some valuable information. Id think you could do the same.
Question, where is your iq at hot idle?
 

6_DoF

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Joined
Sep 23, 2022
Location
Black n Gold Territory
TDI
1.9 ALH XJ
I maxed out the timing adaptation at +500, i was still seeing lower EGT and running better ... it needed more.

i didn't get a chance to load his most recent tune this weekend, worked on another truck.
 

dieseldonato

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Mar 10, 2023
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Us
TDI
2001 jetta
I maxed out the timing adaptation at +500, i was still seeing lower EGT and running better ... it needed more.

i didn't get a chance to load his most recent tune this weekend, worked on another truck.
Interesting, how much bottom end did you lose?
 

6_DoF

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Joined
Sep 23, 2022
Location
Black n Gold Territory
TDI
1.9 ALH XJ
Interesting, how much bottom end did you lose?
the opposite, it was getting better. i feel like something weird was off in the base tune we started with and we should probably delete the earlier trials and just start fresh. a typo, something loaded wrong, something corrupted, but unexpected.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
been thinking about this and it's really screwing with my head lol... i've done enough of these 11mm/.260s that run very well (several of these cars have EGT gauges too and all good there too), as well as 11mm/.230s (not quite as big, but still pretty comparable in size) that something has to be really off, because +500 to the timing maps i gave you initially (the near same tune i run daily in my mk1 for this fueling) is completely off the charts. that's running wayyyy more advance than any tune i've done for 10mm/small nozzles with the longest injection durations, wayyy more advance than a stock 11mm/auto nozzle (~.158) for lower/mid IQ amounts even. and i've messed around with all kinds of advance and tune versions on multiple cars, that amount of advance (especially given the crazy short injection times of 11mm/.260s) should be causing the car to run like total poo with all that pre-tdc combustion, it should be shuddering and have zero power and feel completely strained and undrivable. zero torque.

i'm leaning towards there must simply be a sensor/wiring issue and that the timing being reported by the ecu has to be off by a substantial amount. but oddly, i've seen a very similar issue on 2 other cars (both with .260s coincidentally, with injectors setup by someone different than almost all the others have used. *shrug* very very strange....
 
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burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
the opposite, it was getting better. i feel like something weird was off in the base tune we started with and we should probably delete the earlier trials and just start fresh. a typo, something loaded wrong, something corrupted, but unexpected.
i've gone over it multiple, multiple times. there's always room for a typo, but this is beyond typo territory, and i haven't made any typo/glitch mistakes in quite a long time... aside from sometimes an initial mixup of which map sensor is being used, or forgetting to change the upper limit of the drver wish fuel request map, and i have enough well-running "base tunes" that to make a new, slightly different tune, the chance of that type of error has become very very small. like for your tune, since i hadn't done a BD ecu file tune for 11mm/.260s yet, but have done 11m/.230s (dieseldonato, my brothers alh), so i copy that tune over to a new file, and then plug in the fuel/timing related maps from my mk1 11mm/.260 tune + the vnt17 boost related maps . since dieseldonato/mybrother both have larger 18xx turbos. those maps are mostly the same except your top end fueling is limited to a lower amount, as well as the very top end of boost.

the log data of timing values also "doesn't lie". and apparently the more "advance" is helping. but i think the timing values must be wrong. i've seen another car that was getting very wrong (actual) timing values. that car had some wiring problems with the crank sensor or 3rd injector iirc. but that was a little different, it was showing, at one point, ATDC (Actual, not spec) timing even when at WOT @ 3500 rpm!! and it wasn't smoking!! those values were obvioulsy bogus, as there's no way you could be injecting such a alrge amount of fuel @ 3500 and it be running right with almost zero smoke. gotta be a wiring/sensor issue such that what the ecu thinks is 3.0BTDC is actually 0.0BTDC..... that would make the most sense. other issues like variations in compression and whatnot i don't think could possibly add up to this large of a discrepancy in timing.
 

6_DoF

Veteran Member
Joined
Sep 23, 2022
Location
Black n Gold Territory
TDI
1.9 ALH XJ
how does +500 to your tune compare to the malone stage-3? the fact that this "canned" tune (burpod modified it for the 260's) rips is what made me think some unexpected change happened. it wasn't a small change either, it was like going from NA to boost.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
how does +500 to your tune compare to the malone stage-3? the fact that this "canned" tune (burpod modified it for the 260's) rips is what made me think some unexpected change happened. it wasn't a small change either, it was like going from NA to boost.
to clarify what i did here for others who might be reading - all i did to the malone tune was "hammer mod it in the software" to account for the new QA position. my tunes, i try to get the QA in a more correct position for the injectors. 11mm/.158 (stock auto fueling) idles with pump voltage ~1.54v to get ~4mg hot idle IQ. the larger nozzle you put in, that pump voltage would drop (like how you see if you install larger injectors you'll see your IQ drop). my estimation of .260s would be pumpV of around 1.25v or something like that. the malone tune uses the virtual same pump map for every fueling, which puts you at a pump voltage of ~1.7v for IQ of ~4mg (like a 10mm/.184 stock manual nozzle tune), which isn't correct at all. so i basically just subtracted ~400 (.4v) from the malone pump map so you can run it with where you've hammer modded (down) the pump to run on my tune.

that simply is allowing you to run the malone tune for the current QA position. except for the physical max limit being different (which you're not getting close to anyway, so doesn't matter), it's the same as if you had reloaded the malone tune and then hammer modded the pump back UP by ~.4v - but easier to just reflash a tune than mess around hammering again.
 
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dieseldonato

Veteran Member
Joined
Mar 10, 2023
Location
Us
TDI
2001 jetta
been thinking about this and it's really screwing with my head lol... i've done enough of these 11mm/.260s that run very well (several of these cars have EGT gauges too and all good there too), as well as 11mm/.230s (not quite as big, but still pretty comparable in size) that something has to be really off, because +500 to the timing maps i gave you initially (the near same tune i run daily in my mk1 for this fueling) is completely off the charts. that's running wayyyy more advance than any tune i've done for 10mm/small nozzles with the longest injection durations, wayyy more advance than a stock 11mm/auto nozzle (~.158) for lower/mid IQ amounts even. and i've messed around with all kinds of advance and tune versions on multiple cars, that amount of advance (especially given the crazy short injection times of 11mm/.260s) should be causing the car to run like total poo with all that pre-tdc combustion, it should be shuddering and have zero power and feel completely strained and undrivable. zero torque.

i'm leaning towards there must simply be a sensor/wiring issue and that the timing being reported by the ecu has to be off by a substantial amount. but oddly, i've seen a very similar issue on 2 other cars (both with .260s coincidentally, with injectors setup by someone different than almost all the others have used. *shrug* very very strange....
Pop pressure plays a role in timing as well, we're just assuming everything is right, or close and the spec does have some allowable variance. So of the pop pressure it at the high end of spec or just over the injection pump has to overcome that pressure to lift the needle and start the injecrion event. Thus throwing timing off. I would think with the lift sensor in the injector the ecuwould be able to compensate for wear and adjust, but idk if it's something it does.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
Pop pressure plays a role in timing as well, we're just assuming everything is right, or close and the spec does have some allowable variance. So of the pop pressure it at the high end of spec or just over the injection pump has to overcome that pressure to lift the needle and start the injecrion event. Thus throwing timing off. I would think with the lift sensor in the injector the ecuwould be able to compensate for wear and adjust, but idk if it's something it does.
yes, i've been thinking of pop pressure too, but that also doesn't make sense, because the ecu adapts to that. the ACTUAL timing it's reporting *is* (or should be) the timing - it's using the crank sensor + needle lift sensor from 3rd injector. so in the tune, when you specify you want 1.0BTDC, if it's reporting ACTUAL timing of 1.0BTDC also, that's what it's doing, unless the sensors aren't reading correctly. i think the pop pressure could affect the pump voltage/duration to get the same amount of fueling tho. need to re-read the bosch pump doc and try and see if perhaps there's something i'm misunderstanding on that.

but supposedly (i asked the person who set up these nozzles) they are set to factory pop pressures. the other cars i've not had any problems with .260s are all injectors from xman/powertdi who set the pop pressures to factory, or very close. i think he does 230/310 if you specify 11mm pump. jarod march, i talked to him, i know he's set some large injectors to much higher pop pressures - 260/340 - now thats a pretty substantial difference that i wonder how that affects required pumpV to get the same amount of fuel flow...

edit - i should mention, the person the injectors came from i believe doesn't actually set them up himself, so always a chance he could be mistaken as to what the pop pressure are set at....
 
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dieseldonato

Veteran Member
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Mar 10, 2023
Location
Us
TDI
2001 jetta
yes, i've been thinking of pop pressure too, but that also doesn't make sense, because the ecu adapts to that. the ACTUAL timing it's reporting *is* (or should be) the timing - it's using the crank sensor + needle lift sensor from 3rd injector. so in the tune, when you specify you want 1.0BTDC, if it's reporting ACTUAL timing of 1.0BTDC also, that's what it's doing, unless the sensors aren't reading correctly. i think the pop pressure could affect the pump voltage/duration to get the same amount of fueling tho. need to re-read the bosch pump doc and try and see if perhaps there's something i'm misunderstanding on that.

but supposedly (i asked the person who set up these nozzles) they are set to factory pop pressures. the other cars i've not had any problems with .260s are all injectors from xman/powertdi who set the pop pressures to factory, or very close. i think he does 230/310 if you specify 11mm pump. jarod march, i talked to him, i know he's set some large injectors to much higher pop pressures - 260/340 - now thats a pretty substantial difference that i wonder how that affects required pumpV to get the same amount of fuel flow...
Higher pressure also leads to better fuel atomization, my guess is head trying to make up for bigger injectors haveing atomization issues. I'd be a bit worried about cam plate wear in the ve...may be it's not an issue.
 

6_DoF

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Joined
Sep 23, 2022
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Black n Gold Territory
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1.9 ALH XJ
power steering:
the VW pump is externally identical to the XJ pump ... but what about internally?

now that the roads are getting slick and i'm screwing around drifting this thing, the steering is too slow. it actually feels held back by the hydro's. any thoughts if this pump might just be junk, or if the VW runs way less psi/flow to their rack steering than the jeep needs in the box?
 

PickleRick

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Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
While I've not had any experience with jeep boxes my ifs yota has zero issues with the VW ps pump on tires that are @33"x11.5".

The steering is tighter and more responsive than my factory excursion on 35s on 4 inch lift as well as a factory disco 2 on a 3 inch lift running same size tires as my yota.

I don't know how new your front end is. When I did my build it was nearly a full restoration. upgraded idler arm assembly with bronze bushings, all new tie rod ends, pitman arm, steering box, steering damper, A arm bushings upgrade to polyurethane, OEM wheel bearings, and ball joints. So everything new from either MOOG or OEM supplier. Even new sway bar end links, drop brackets and bushings.

Much like the xj, the yota ifs can reveal lots of underbuilt/worn parts once it's lifted and larger tires tossed on it. The xj is a little more famous for death wobble than the ifs yota.
 
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6_DoF

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Sep 23, 2022
Location
Black n Gold Territory
TDI
1.9 ALH XJ
i've been lucky to have zero death wobble hints at all, but it is like you said mostly new now. everything is really smooth, it's just when i try and whip the wheel really fast that it's all lame duck.

i guess it could be the steering box too ... i'll have to swap something and see what happens i guess.
 

03Golfer

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Joined
Apr 8, 2020
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Canada
TDI
03 Golf, 92 Toyota swap (ongoing)
I seem to recall reading about people actually decreasing pressure on the VW pumps in Toyota applications. However it could be a lack of volume causing a dynamic pressure drop in your case. Are there faster ratio steering boxes available?
 

PickleRick

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Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
Do you remember what size bearing jaw clamp you used? There's a 4" one at harbor freight and then a kit with both a small 2" ish one and 3" one.
 

6_DoF

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Sep 23, 2022
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Black n Gold Territory
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1.9 ALH XJ
well, after a TON more work on this thing it's in way way better shape now. but now I'm building a shop out back this spring and should really entertain selling it again. this batch of work was a lot more time than cash though, i'm still just over $10k invested.

- completely rebuilt ax-15 with a few new gears
- vnt-17
- front/rear bumpers built out
- rear locker
- completely new headliner
- proper alignment
- tune mostly fixed up

Burpod has been helping with the tune and i'll include all the programming cables with the jeep. he re-did the fueling on the tune i had and it's much better. something with this build though it's playing nice with his from-scratch tune and we've not been able to figure out why yet. in the mean time though, she's a ripper. he did diagnose a vac leak and i got it fixed up, but something else is not as expected. i've also been REALLY bad at getting logs for him to look over though.
 
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6_DoF

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Sep 23, 2022
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Black n Gold Territory
TDI
1.9 ALH XJ
so recently, as i start driving from a cold start, I'm having a stalling issue. just as the power starts to come in the engine stalls and barks the crap out of the turbo. sometimes i just need to let the clutch out and bump-start it back to life ... but occasionally after the re-start it's only running on like 1.5 cylinders. get it to rev and it clears up then runs totally normal.

it has always started pretty hard unless up to temp.

you think this pump just needs rebuilt?
 
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