Actual Boost vs Request boost problem

makos101 · Sep 11, 2011

Ive just got a Malone stage 3 tune. I was having under boost problems putting my car into limp mode. So I adjusted my new actuator and its now running at optimal boost. Now my problem is that i'm not building boost early enough.

Please check out this log of Actual vs Requested boost and let me know what you think the problem is. Could it be my n75 valve being faulty and it doesn't produce the vacuum needed to close the actuator and make boost? when testing my actuator with a mity vac the vein arm and actuator moved at the right vacuum pressure.

Thanks for all the help

JFettig · Sep 11, 2011

Have you talked to Malone about this at all?

Define the right pressure - where it moved, what did it lift at and stop? Did it move smoothly or did it jump?

You can test your N75 by swapping it with your N18(EGR solenoid).

makos101 · Sep 11, 2011

JFettig said:
Have you talked to Malone about this at all?

Define the right pressure - where it moved, what did it lift at and stop? Did it move smoothly or did it jump?

You can test your N75 by swapping it with your N18(EGR solenoid).

Yes ive talked to Malone.

My tdi guru in nj mike tested it. It first moved at 2-3 and was fully open by 17. I think it was smoothly. Its in a hard place for two people to see.

So i can just swap the n75 and the n18?

VDUB TECH · Sep 12, 2011

is your maf ok?check maf in 2nd WOT if it doesnt reach atleast 800 its junk.Is the actuator new? , it might be binding/or the veins might be sticky.Id remove the actuator to verify that the veins are ok ,kinda hard to tell with the actuator installed.

dieselfuel · Sep 12, 2011

Before you adjusted the actuator to move at 2-3, where did it start to move?

The optimal setting is 5. Try it there.

What is your IQ set at? I would set the IQ to the default number in the adaption channel (VCDS). If it's not 5, I would hammer mod. it to 5. If you're running the stock VNT-15 turbo, the optimium setting will be some where between 4-6, imo.

Try it at 5. If it lacks power, lower the IQ number til it smokes., then raise the IQ a little til it stops smoking.

If at 5 you have a lot of smoke, do the opposite of above.

Let us know how it works out for you,

df

makos101 · Sep 12, 2011

dieselfuel said:
Before you adjusted the actuator to move at 2-3, where did it start to move?

The optimal setting is 5. Try it there.

What is your IQ set at? I would set the IQ to the default number in the adaption channel (VCDS). If it's not 5, I would hammer mod. it to 5. If you're running the stock VNT-15 turbo, the optimium setting will be some where between 4-6, imo.

Try it at 5. If it lacks power, lower the IQ number til it smokes., then raise the IQ a little til it stops smoking.

If at 5 you have a lot of smoke, do the opposite of above.

Let us know how it works out for you,

df

is your maf ok?check maf in 2nd WOT if it doesnt reach atleast 800 its junk.Is the actuator new? , it might be binding/or the veins might be sticky.Id remove the actuator to verify that the veins are ok ,kinda hard to tell with the actuator installed.

Before the arm was to long and it required to much vacuum to move it a little bit. What is IQ? I have a vag com but I dont know how or what IQ is.

What block do I log to see if the MAF is ok?

Thanks for all the help guys.

JFettig · Sep 12, 2011

skip the IQ stuff.

unplug your maf and take it for a spin and see what it does

MAF is block 3 I believe.

Jon

makos101 · Sep 12, 2011

JFettig said:
skip the IQ stuff.

unplug your maf and take it for a spin and see what it does

MAF is block 3 I believe.

Jon

I would but I my boost Gage is not tapped at the moment. Saturday night when I adjusted the actuator. I got alot of boost and it blew my upper intercooler pipe into a pulley on the way back home(big leak in the pipe

. I just got a new pipe but I have yet to tap the pipe. Should I wait till i have my gauge hooked up so i can see if the boost actual boost is closer to requested with my maf unplugged? Im planning on tapping it Thursday night.

Thanks

JFettig · Sep 12, 2011

graph it in VCDS and use hose clamps

makos101 · Sep 18, 2011

Just did a log with the MAF off. It went into limp mode. I sent the log to malone too. He says my maf is good.

Should I try swapping my n75 valves next? Thanks for all the help guys.

JFettig · Sep 18, 2011

It wouldn't hurt to swap N75 valves, you can use your N18 too.
You should also check for vacuum leaks - check all your vacuum lines.

makos101 · Sep 27, 2011

http://www.youtube.com/watch?v=2dIU0HYD8WY my actuator being tested through vagcom let me know what you guys think

robnitro · Sep 27, 2011

Looks kind of slow to go down, you see it drop fast and then take some more time to do the last bit of travel.
With a vacuum gauge, check how much vac is getting to the vac side of the n75. It should be able to climb to around 30" Hg or more. If it is low, you may have a vacuum leak, or the N18, or N239 (one for ASV) might be leaky even when not in use. To test that, connect the vac gauge directly to the T that comes after the check valve and splits to the vac ball. If it is much better there, then you connect N18 N239 one at a time.

Also, you can check at engine idle vac line that goes out to turbo, mine is around 20" Hg, not sure what other tunes use.

If all else fails check out what I found out about my vacuum pump output :
http://forums.tdiclub.com/showthread.php?p=3530483#post3530483

azibi_130 · Sep 28, 2011

i also think that the actuator is closing slow for my opinion...maybe geometry is dirty??

dieseleux · Sep 28, 2011

Put full vacuum on actuator, with hot engine at neutral, run at 2000rpm and see if turbo pressure rise to 2-4psi range.
I think the vane a too open to make good spool, exemple: on 17VB, 39mil before the vane touch the stop screw make +500rpm on spool!

Dieseleux

Actual Boost vs Request boost problem

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