Pages: [1] 2
Author Topic: VR6 Turbo - load cut?  (Read 14686 times)
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« on: March 18, 2013, 01:54:55 PM »

I'm tuning Golf IV VR6 Turbo. Siemens 630cc injectors, stock 3'' MAF, t3/t4 turbo.

Moded maps:
KRKTE
A little richer than original in highest loads tuned in ECM software
KFMLDMX (I had "MAF signal is too high" DTC)

I have a problem. When i was running at dyno the load at 4000rpm is about 130% and I have about 0,7bar boost, hold about 11 - 11,5 AFR. At about 4200rpm the load suddenly decrease to 90% and AFR rising to 15-16 and engine sputter. I don't have any DTC but general lambda is switched off in that moment (come down to "0" value on VCDS). What could be wrong?

Best regards
« Last Edit: March 18, 2013, 01:58:53 PM by mbwiejska12 » Logged
nyet
Administrator
Hero Member
*****

Karma: +607/-168
Offline Offline

Posts: 12270


WWW
« Reply #1 on: March 18, 2013, 02:15:26 PM »

no clue. Log.

throttle cut?
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« Reply #2 on: March 18, 2013, 02:40:38 PM »

Tommorow I will post logs. I think this is not throttle cut because engine want to go up. But it's like load cut caused by moving to another map in ECU because afr suddenly escalate to 15-16 in that moment. I don't know why this happens...
Logged
IamwhoIam
Hero Member
*****

Karma: +52/-115
Offline Offline

Posts: 1070


« Reply #3 on: March 19, 2013, 06:13:40 AM »

Have you 100% eliminated hardware as a potential cause for your cuts? Like a dead fuel pump?
Logged

I have no logs because I have a boost gauge (makes things easier)
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« Reply #4 on: March 19, 2013, 11:14:24 PM »

I'm posting logs. Is it possible that stock 3'' maf is too small to this setup and this is the cause of cuts? Other hardware potential causes are not.
Logged
krazydbiker
Full Member
***

Karma: +4/-1
Offline Offline

Posts: 202


« Reply #5 on: April 01, 2013, 09:35:50 AM »

from what i see in your logs, it seems like the maf is hitting over 300g's which is like 4.7 volts? which is probably around maf limit, you sure thats 3 inch?

turn the boost down a little and see if your problem goes away, i have a feeling it will
Logged
IamwhoIam
Hero Member
*****

Karma: +52/-115
Offline Offline

Posts: 1070


« Reply #6 on: April 01, 2013, 12:29:22 PM »

Are you sure your fuel pressure is remaining constant throughout a pull?
Logged

I have no logs because I have a boost gauge (makes things easier)
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« Reply #7 on: April 01, 2013, 03:17:51 PM »

The problem was genuinely with MAF. This was stock VR6 maf and it have 4.7V at about 5000rpm. I changed to S4 B6 3,5 inch and now it's perfect. Smiley
Thanks Smiley
Logged
ddillenger
Hero Member
*****

Karma: +641/-21
Offline Offline

Posts: 5640


« Reply #8 on: April 01, 2013, 03:22:11 PM »

The problem was genuinely with MAF. This was stock VR6 maf and it have 4.7V at about 5000rpm. I changed to S4 B6 3,5 inch and now it's perfect. Smiley
Thanks Smiley

What did you do about mlhfm?
Logged

Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience!

Email/Google chat:
DDillenger84(at)gmail(dot)com

Email>PM
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« Reply #9 on: April 01, 2013, 03:38:45 PM »

What did you do about mlhfm?

I was surprised by this, but I didn't do anything with it. It works fine on stock mlhfm.
Logged
Jrmillsr
Newbie
*

Karma: +0/-0
Offline Offline

Posts: 23


« Reply #10 on: April 05, 2013, 08:25:30 AM »

I'm building a vrt as we speak. I thought with that setup you would want the 4 inch maf?
Logged
Gonzo
Sr. Member
****

Karma: +21/-30
Offline Offline

Posts: 483


« Reply #11 on: June 12, 2013, 09:06:22 PM »

I was surprised by this, but I didn't do anything with it. It works fine on stock mlhfm.
Did you use the stock sensor?
Logged
ddillenger
Hero Member
*****

Karma: +641/-21
Offline Offline

Posts: 5640


« Reply #12 on: June 12, 2013, 09:11:26 PM »

It's underscaled if he's using stock MAF table.
Logged

Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience!

Email/Google chat:
DDillenger84(at)gmail(dot)com

Email>PM
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« Reply #13 on: July 15, 2013, 07:43:49 AM »

Did you use the stock sensor?

Yes, this is stock sensor
Logged
mbwiejska12
Jr. Member
**

Karma: +1/-0
Offline Offline

Posts: 37


« Reply #14 on: July 16, 2013, 02:05:04 AM »

Now I have another problem with that Golf. I don't touch the ignition maybe I done this a little and it always and still retard the ignition by knock sensor on knock corrections. On max load it can retard about 10 degrees. I have external knock sensor and I don't hear a knock. It does not help also if I put 100oct. V-Power fuel. I don't know what it could be... There was only done KRKTE, MLHFM is pull down and fueling map in ECM. Golf has 1,2 bar boost and have about 300hp now, but it should be about 310hp on 0,7 bar.
Logged
Pages: [1] 2
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.022 seconds with 17 queries. (Pretty URLs adds 0s, 0q)