Stop Screw Adjustment 1749VC Hybrid

[Dan FR]

What rpm/gear are you hitting how much boost? Logs?

Are you getting any black smoke on spool? Did we ever get to see decent N75 data along with the boost spec vs actual?

 

[S10EAT]

Dan,

24-25 PSI Boost is being requested from 2100 RPM. I'm logging runs until around 4500 RPM+.

This is the odd thing, I have no smoke whatsoever, could a poor lift pump cause lag up till a certain RPM?

I did post several logs but they weren't high res, please see below for link to log I did this morning.

http://i1181.photobucket.com/albums... FR/BoostLog30102014_zps0847550b.png~original

Thanks,

S10EAT

 

[Dan FR]

Just had a quick look at the link on my phone as can't access PB in work.

Does look very laggy, and the boost control isn't great. The N75 graph looks horrid, up and down with a nasty boost spike between 3.5 and 3.8k. More could be done with the N75 to get the boost in sooner too.

Actuator rod looks to be slightly too long but hard to say without knowing what's going on with the fuelling and the rest of the map

What exhaust do you have? No smoke at all, especially on a poor spooling turbo, is a good indication that you dont have enough fuel in there. Can't say for sure as i haven't seen the fuelling side

Can you repeat the log you've done, exactly the same way, but log fuelling (008 and theres one other for start of injection and injection duration).

Sounds like now would be a good time to send these logs to the guy mapping it and get an updated map too?

 

[S10EAT]

Just had a quick look at the link on my phone as can't access PB in work.

Does look very laggy, and the boost control isn't great. The N75 graph looks horrid, up and down with a nasty boost spike between 3.5 and 3.8k. More could be done with the N75 to get the boost in sooner too.

Actuator rod looks to be slightly too long but hard to say without knowing what's going on with the fuelling and the rest of the map

What exhaust do you have? No smoke at all, especially on a poor spooling turbo, is a good indication that you dont have enough fuel in there. Can't say for sure as i haven't seen the fuelling side

Can you repeat the log you've done, exactly the same way, but log fuelling (008 and theres one other for start of injection and injection duration).

Sounds like now would be a good time to send these logs to the guy mapping it and get an updated map too?

Dan,

Thanks for that.

What would normally cause duty cycle to fluctuate so much? Just one day it started doing this and hasn't been the same since no matter how the actuator arm is adjusted.

Should it not start from 25% ish and rise to 70-80% at around 4000 rpm? Mine as you can see does not increase in this normal way, any ideas why N75 would go up and down on it's way up the rev range?

As for the lag I'm going to attack the stop screw again as there's probably some more adjustment on that, currently at 192 so perhaps make it just past 200-215?

I have standard downpipe, cut has been cut out and replaced with straight pipe and a aftermarket muffler at the back.

I'll ask John for another map but didn't want to waste his time if something is mechanically incorrect still.

I shortened the actuator so that it hits the stop at 18hg but think that might be too far (more overboost), please see below.

http://i1181.photobucket.com/albums/x439/DLSPS2011/actuator18hg_zpsa3fe3f8e.png~original

Thanks,

S10EAT

 

[S10EAT]

Group A: '011
Engine speed Spec. intake press. Actual intake press. D.cycle MAP
TIME 2850-3150 2300-2600 2200-2800 35-80%
MARKER STAMP /min %
0.01 1911 996 1356 35.1
0.83 2079 2640 1548 29.1
1.63 2289 2700 2076 41.8
2.43 2562 2712 2520 53.4
3.23 2856 2712 2772 61
4.03 3129 2712 2892 57.8
4.83 3402 2712 2892 45.4
5.63 3675 2712 2952 59.4
6.43 3927 2712 2916 64.9
7.23 4158 2712 2688 57
8.03 4347 2664 2640 55.8
8.83 4536 2520 2580 59.4
9.63 4284 1116 2244 50.2
10.43 3381 1056 1404 46.2

 

[S10EAT]

Group B: '008
Engine speed IQ driver's req IQ via rpm(Torq) IQ via MAF
TIME 2850-3150 65-70 52-54 52-60
STAMP /min mg/R mg/R mg/R
0.42 1827 70 57.6 40.4
1.23 2184 70 62.4 56.8
2.03 2415 70 65.6 74.4
2.83 2709 70 67.6 85.2
3.63 3003 70 67.2 90.4
4.43 3276 70 65.6 90
5.23 3549 70 64 89.6
6.03 3801 70 62.8 88.4
6.83 4032 70 61.2 81.6
7.63 4263 70 60 76.8
8.43 4452 70 58.4 75.2
9.23 4620 70 55.6 72.4
10.03 3360 0 65.2 51.2
10.83 3339 0 65.2 40.8

 

[S10EAT]

Might need to lengthen the actuator...whoops

 

[Dan FR]

Dan,

Thanks for that.

What would normally cause duty cycle to fluctuate so much? Just one day it started doing this and hasn't been the same since no matter how the actuator arm is adjusted.

Should it not start from 25% ish and rise to 70-80% at around 4000 rpm? Mine as you can see does not increase in this normal way, any ideas why N75 would go up and down on it's way up the rev range?

As for the lag I'm going to attack the stop screw again as there's probably some more adjustment on that, currently at 192 so perhaps make it just past 200-215?

I have standard downpipe, cut has been cut out and replaced with straight pipe and a aftermarket muffler at the back.

I'll ask John for another map but didn't want to waste his time if something is mechanically incorrect still.

I shortened the actuator so that it hits the stop at 18hg but think that might be too far (more overboost), please see below.

http://i1181.photobucket.com/albums/x439/DLSPS2011/actuator18hg_zpsa3fe3f8e.png~original

Thanks,

S10EAT

Duty cycle is caused by the N75 map being out, totally out, and the ECU having to step in once boost control deviates too much from what it wants and is expecting to see by following the N75 map

It will start from 25%, or even 20% at very low rpm, by 2K RPM its normal for it to be in the 40's, or 50's, even higher on a quick spooling turbo. It all depends on the setup - every one is different. It should hit around 75-80% at 4000 once we have enough fuel going through. The more fuel you add the more N75 you will need.

Stop screw is fine, don't adjust it any further

So your exhaust should flow fairly well aside from the restrictive downpipe. No black smoke means nowhere near enough fuel

You definitely need a new map. I really dont like how the map is done, not using the MAF sensor for fuelling at all, all reliant on the Torque Limiter which doesnt take in to account the actual airflow. Different way of tuning i guess.

Did you not log the other fuelling i requested? The one that shows injection duration and start of injection? To be honest without seeing how the map is calibrated, the 008 log isn't that helpful, all it displays is what it 'thinks' it is injecting, based on the mpa your tuner has written

Don't touch the actuator any further, you really need to work on the map that's on there in my honest opinion, it look's to be a long way off

 

[S10EAT]

Duty cycle is caused by the N75 map being out, totally out, and the ECU having to step in once boost control deviates too much from what it wants and is expecting to see by following the N75 map

It will start from 25%, or even 20% at very low rpm, by 2K RPM its normal for it to be in the 40's, or 50's, even higher on a quick spooling turbo. It all depends on the setup - every one is different. It should hit around 75-80% at 4000 once we have enough fuel going through. The more fuel you add the more N75 you will need.

Stop screw is fine, don't adjust it any further

So your exhaust should flow fairly well aside from the restrictive downpipe. No black smoke means nowhere near enough fuel

You definitely need a new map. I really dont like how the map is done, not using the MAF sensor for fuelling at all, all reliant on the Torque Limiter which doesnt take in to account the actual airflow. Different way of tuning i guess.

Did you not log the other fuelling i requested? The one that shows injection duration and start of injection? To be honest without seeing how the map is calibrated, the 008 log isn't that helpful, all it displays is what it 'thinks' it is injecting, based on the mpa your tuner has written

Don't touch the actuator any further, you really need to work on the map that's on there in my honest opinion, it look's to be a long way off

Thanks Dan, I was going to try going back to the standard map and see if duty cycle goes back to normal, may have to start from scratch on the map.

I'll get the injection duration logs on the way home tonight, do you want me to record 008 and that together?

I had a milltek downpipe on my previous 110 tdi and that helped spooling no end even on a 1749V turbo, do you reckon I should invest in a downpipe?

Thanks,

S10EAT

 

[Adam4D]

Log 004 for duration, 008 shows nothing if decalibrated

Not got time to look over logs tonight or tomorrow as busy servicing and mapping a 225 1.8t

Stop screw can ruin a turbo very quickly be careful, Go too tight and the car will drive worse,choke itself at full throttle and pressure in the manifold will sky rocket.

If you wish, you can send me the file and I'll have a look over it and correct where needed for free but as said not free till Sunday

 

[Dan FR]

Did you make any progress with this?

 

[S10EAT]

Ok I thought it was time for an update.

I have performed a mr muscle turbo clean on the turbo vanes and just last night did a diesel purge with liqui moly.

The results are much smoother boost curve and controlled boost as opposed to lots of overboost.

<a href="http://s1181.photobucket.com/user/DLSPS2011/media/PD150-64act_zps4c6ceefc.png.html" target="_blank"><img src="http://i1181.photobucket.com/albums/x439/DLSPS2011/PD150-64act_zps4c6ceefc.png~original" border="0" alt=" photo PD150-64act_zps4c6ceefc.png"/></a>

Duty cycle is set at 64% @ 4000 RPM, I realise this isn't where it's meant to be but at the moment it's ok how it is.

I checked the basic settings 011 again and I have a 190-204 mbar difference.

No matter what has been changed on the turbo, ie length of the actuator, length adjusted on the stop screw (Has been between 144-204 mbar throughout my testing at some point). This has had NO effect on the spool which has always come in to meet specified boost at a lousy 27-2800 rpm.

What else am I missing that could cause this poor spool? clearly nothing I have adjusted on the turbo has made this any better?

Ideas? I'd rather the car had a good spool than loads of power, pulling away from junctions at the moment is a nightmare unless I hold the revs close to 2500 rpm and release.

Thanks guys.

S10EAT

 

[S10EAT]

http://i1181.photobucket.com/albums/x439/DLSPS2011/PD150-64act_zps4c6ceefc.png~original

 

[Adam4D]

Had this before on a vc hybrid on a pd140. Nothing you do the actuator/stop screw improves the spool.

Turbo is built with shite tolerances

 

[S10EAT]

Thanks Adam.

I should just go back to a bog standard PD150 turbo?

Tbh I wish I had never gone down the hybrid route now, very put off.

How much do the 1756vk turbos go for now?

 

[Adam4D]

1756vk on welded manifold would be good but need downpipe etc

Or just fit a new pd150/160 turbo and a good remap too suit it.

 

[S10EAT]

Thanks, any idea where the cheapest place for a new pd150 turbo would be?

Thanks,

S10eat

 

[Adam4D]

Cheapest would be finding a broken one with good unmarked housings and chucking a new core in from melett

 

[S10EAT]

Adam,

Who is Melett and where can I purchase?

Thanks,

S10EAT

 

[S10EAT]

I thought for the hell of it I would buy a torque wrench today and attempt to adjust the syncro angle as it was fluctuating around -1.1 to -1.7, not a massively out of spec but wanted to get it as close to -0.5 to 0.0 as possible.

So following the guide from myturbodiesel.com I proceeded to dismantle the intercooler piping and remove the cambelt cover.

I loosened the three 13mm bolts and then put a 18mm socket on the centre bolt and tapped it in the clockwise direction to advance the timing. So at this point I thought I was doing this correctly.

However, upon tightening the bolts up to 18 ft/lbs and putting everything back together I found that vag-com was displaying that the timing had become more retarded! now sitting at -2.2 to -2.8?

Can someone please explain why moving the pulley in the clockwise direction would retard it? As I thought it was anti-clockwise for retarding and clockwise for advancing??

Any thoughts?

Thanks,