NefMoto

Hi Guys,

I've compared my Tune with some other 1.8t... It seems that my enginge is struggling at higher RPM with mass air flow.

I get about 165g/s maximum mass air flow with stock AND tuned file. I've seen up to 250g/s mass air flow at other 1.8t engines...

So there must be a hardware problem, but I don't know what... Maybe you can help me.

Today i checked the cats and it looks fine to me, they are not clogged. What should i check next? N75? Air Filter?

Attached log files of a Stock and a tuned WOT-run.

Many thanks in advance.

Here the files...

Make sure your inlet isn't collapsing

Hey there!

I'm still struggling with this issue...

What I did so far:

1. spent some money on new ccv hoses underneath the intake manifold. one of them was broken.

It was the one between the manifold and the one-way valve. So i lost some boost there.
Now the engine has about 0,2 bar (3 psi) more pressure around Pmax. Second effect was, that i "lost" some mass air flow -> delta of about 10g/s.
This makes sense so far, the MAF Sensor is reading now a little less, because the air isn't escaping through this hose.
If I do a leak test up to 2,5 bar (36 psi) there is no fluctuation of air. The air is slowly blowing by the pistons. You can hear it, if you take out the dipstick for the oil. I put on pressure at the first hose after the pressure pipe. So it still could be, that i lose some air between charger and this spot (hose to dv or to n75). I tried to check this both hoses by dismounting them and do a pressure check. They also seem to be ok.


2. bought a new DV and installed it. I heard some strange noise when the charger was boosting. thought the membrane could be torn. the noise is still there sometimes...

One thing with the DV which I don't understand completely: The charge pressure is "controlling" the DV? So for example, if the engine has 1 bar (14 psi) boost pressure, this pressure is "closing" the DV? This 1 bar is on the little pipe on the top of the DV to hold it closed? So what is this N249 for? Maybe there is something broken and the pressure is not closing the DV correctly?
If YES, this could be an explanation for the low mass air flow? It wold be an open circuit from "after charger" to "front of charger".

3. installed a gopro to see if the inlet is collapsing at WOT.

There was no collapsing visible. I ended up buying the SAMCO inlet hose. Still no effect. Same MAF as before.

4. new air filter and removing the inlet before the airbox.

no effect.


Attached i have an actual log. There you can see the still low mass air flow, although the engine should be able to do ~200g/s. The second issue is that the actual boost pressure at high rpm is also really low. This issues are the same with stock software! I'm pretty sure it's still a hardware problem.

Do some of you have some ideas? Maybe the MAF Sensor is broken? The values below 3000 rpm seem to be ok if I compare it to other 1.8t BAM engines. If I buy a new MAF-Sensor it wouldn't solve the problem with the "low" boost at high rpm?

one more thing for information the idle is a bit oscilating...

Thanks in advance.

log...

What turbo do you have?

stock! k04-23

For the boost, weak actuator? I had issues with mine and had to change it.

Maf readings... I guess try a new maf, they tend to under read when they die don't they?

Looks fine to me. Turbos are struggling to keep up, could be going out. Might need to increase Ilimit until your req meets actual, but odds are that is 95% dc.

Also, you should be logging ps_w

I checked the actuator by applying negative positive pressure with a syringe... it held it's position for more than five minutes...

The WGDC looks also fine to me if i compare it to similar engines. until rpms > than 3500 rpms... it looks like there is a bottleneck somewhere (for me). (intake or exhaus system)

consequences of this bottleneck is stagnating mass air flow --> and the effect of this is low boost, since the turbine is not getting enough exhaust mass air flow.

I also calculated mass air flow with the AFR values and the injector on time... it also seems to fit that the maf readings are right...

this above is all just thinking! maybe I'm wrong...

I tried to increase I Limit so that i had 95% WGDC above 4500 rpm all the time... no difference in boost!
Like i said, i think it's not enough exhaust mass flow through the turbine...

next time i will log ps_w

That means your turbo is done or your wg is leaking

he is most likely correct. i have ran into a leaking wastegate a few times before on 1.8t, very difficult at times to diagnose.   pull the downpipe off and feel the wastegate flap. If it can rotate or move about then either adjust your wastegate preload or replace the turbo.

i will take a look at the wg when I find time...

Today I did a log with ps_w.

msdk is oscillating really weird above 4000 rpm... hardware wasn't touched.

Hi again!

Today i did some logging with disconnected (electrically) N75. I've read, that the boost pressure should be ~0.5...0.6 bar (~8...9 PSI) with k04-23.
Can someone confirm this values?

Take a look at the log and the screenshot. The boost is about 0.3 bar (5.5 PSI).

Yesterday i dismounted the downpipe and had a look at the turbine-wheel ant the wastegate. Looks pretty fine to me!

@ spacey3: it seems that the actuator is really weak. the membrane seems to be ok (it holds its position). But the spring seems to be to weak...

Is it a good idea to increase the spring preload? Has someone experience with that? Otherwise the best idea would be to buy a new actuator...

That is VERY low... i'd get a new actuator.

1. New actuator, same pressure (unplugged N75)... see screenshot. Should I increase the preload of the spring?

2. After installing a third MAF... the values seem to be ok -> up to 220 g/s.

3. Attached a screenshot and log of 5th gear. above 5500 RPM the engine begins to struggle to hold the desired boost pressure (I don't have any experience with 1.8t k04 engines... maybe it's not possible to get more pressure, but it's just slightly above stock). Maybe the low preload of the actuator spring has also affect on this?
(I know I have to work on fueling)

correct me if im wrong but if this is a BAM with stock K04 the airmass of 220g
with this little boost doesnt make sense

you hitting bts because of very high egt

thatswhy your fueling and timing is off most if the time

where is your nmax?

correct!


OK, maybe it's because it is a Eberspächer MAF and not a Bosch. It has the same OE-Partnumber.
You say "little boost", so this engine should be able to do more? in which RPM areas?


Yep, that's why I wrote I have to work on fueling.


Stock -> 6800 rpm.

Its 120€ to get a genuine bosch maf in germany.

1.8t K04 stage1 should see 1,4bar at least.

I dont understand why your EGT is 900+ °C in the mid rpm range.

The log is in 5th gear, full boost (18psi) for 1k rpm at 14.0 afr I would think is the reason why it gets so hot so quickly

Ah, better do 3rd gear Logs.

As it's been brought up though, I think it should be resolved.

Shouldn't we generally be decreasing the afr as boost rises and then hitting rich peak at peak boost?

Something for you to look at !nfern0.

Yes of course, I'm aware of that. The next time I flash the ECU there will be more fuel. ;)

But this will not solve the problem, that the car isn't reaching it's requested boost above 5000 RPM, although it's just a little bit above stock.

Same question again: Is the pressure of about 0.3 bar with disconnected N75 too low?

Should be 0,5bar

...

It's just had one?

He replaced his Wastegate Actuator against a new one already.
How did you replace it or which values did you adjust it to?

If you did it right and it still builds no boost of 0,5bar without N75 connector i would say turbo is dead.
Would recommend to unplug the pressure line to the wg actuator and do a test drive very very careful.

It should build massive boost without line connected.

I mounted the WG-lever at the same position on the actuator-rod where it was with the old actuator. Could be that someone in the past of the car has misplaced it...

I will disconnect the N75 again and will increase the spring preload, until i get about 0,5 bar. OK?

I dont know whats the right way to do it on a stock k04.
Is the WG actuator a genuine borg warner part or eberspächer :P

according to the internet: mount the actuator in place to the wg is shut. give it another 360 degree on the nut to tighten it a bit more.

3-5mm preload I got told and is what my k04 is set to.

If you have to add a bunch of preload just to get cracking pressure above .3 bar you are in BIG trouble.

Hey guys,

it's been a while. Had a lot to do with work and stuff, but I've reactivated my project.

The problem is/was I think for 99% the following --> see picture 444.jpg.

There was some "oil coal" building up under the heat shield under the turbine wheel. As you can see the turbine wheel was grinded by the shield.

Brought the turbocharger to the guys from TTE. they are about 10km away from the place I live. :)

Now I've got the TTE300 installed in the car. First run was yesterday. Unfortunately one of the coils died and it had misfires under high load.

I posted this, because maybe some of the new useres have some similar issues.

OK!

Did my first Log yesterday. Hardware should be OK now. Had the engine out in winter and did a lot of stuff to it. Now everything should be finde hardware-wise.

Finally I can start tuning... :D

So, after the first log it seems that I have to work on the PID-Controller. The I-Value seems too high, so the boost is overshooting even out of the sensors range...

After having a look at the FR I understand it that way:

lditv_w is in between the ranges of ldimn and ldimx.
ldimx is determined by KFLDIMX.
ldimn = ldimx - value out of LDDIMXN

so I would reduce the values of KFLDIMX, is this correct?