Pages: [1] 2
Author Topic: WTF is wrong with my MAF  (Read 13650 times)
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« on: April 09, 2013, 05:41:58 PM »

So against the general opinion of this here forum, I've been running MAFless for the past year or so. My car is Wideband 4B0906018CH so it's closed loop all the time.

I've decided I've had enough of the MAFless game, as I'm not sure how to go about removing it the "right" way. I zero'd a few codewords and FF'd a few pressure ratio maps, and it runs great when its warm and at WOT. Cold starts is another issue though, with AFRs dipping to 10.5-11ish for no reason and then slowly climbing back to a reasonable 12-14. I'd rather go back to MAF now.

Problem is when I plug my MAF in, the AFRs go >18 and it idles like shit, obviously. I logged it at idle, and have attached the logs here. MAF airflow is ~6 g/s with TTQS's fully defined TT225 MLHFM, and ~4 g/s with another MLHFM I got from an OTS tune that calls for the TT225 housing.

No boost leaks or leaks between MAF and turbo. Intake consists of a 3 in U-bend off the turbo to the TT225 MAF housing with a AEM air filter on the end. KRKTE and TVUB also attached for my shitty deka 630s.
« Last Edit: April 09, 2013, 05:46:05 PM by catbed » Logged
nyet
Administrator
Hero Member
*****

Karma: +607/-168
Offline Offline

Posts: 12268


WWW
« Reply #1 on: April 09, 2013, 07:36:55 PM »

Should be trivial to fix by only watching short term fuel trims.



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
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #2 on: April 09, 2013, 07:55:02 PM »

Should be trivial to fix by only watching short term fuel trims.

I will go check. TVUB too low?
Logged
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #3 on: April 10, 2013, 01:29:03 PM »

Should be trivial to fix by only watching short term fuel trims.

Care to clarify?

I adjusted TVUB to the values located in this thread


Now it starts nice, and holds an acceptable AFR for about 5 seconds. Then it just sweeps slowly to 18. What bothers me is that the logged wideband o2 voltage stays at ~1.49 volts, and the logged current AFR is 14.7, even when my UEGO says -- from being too lean. I have had a B1S1 Malfunction in circuit DTC since I coded out my secondary o2s via ESKONF, but is it possible my primary o2 is actually dead?

Block 99 in VAGCOM says o2 control is off. Attached is a log with the changed TVUB.
« Last Edit: April 10, 2013, 01:30:38 PM by catbed » Logged
nyet
Administrator
Hero Member
*****

Karma: +607/-168
Offline Offline

Posts: 12268


WWW
« Reply #4 on: April 10, 2013, 01:31:44 PM »

I'd definitely check or replace your primary o2 sensor. That doesn't sound right.
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
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #5 on: April 10, 2013, 02:01:22 PM »

I'd definitely check or replace your primary o2 sensor. That doesn't sound right.

Thing is, with the MAF unplugged, o2 regulation turns on and it holds a consistent AFR. I did some logging the other day for KFLDRL calib, and logged current AFR matched requested. The o2 voltage matched as well.
Logged
nyet
Administrator
Hero Member
*****

Karma: +607/-168
Offline Offline

Posts: 12268


WWW
« Reply #6 on: April 10, 2013, 03:12:54 PM »

There really isn't much to MAF based fueling.

KRKTE, TVUB, KFWWL and the various MAF maps...
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
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #7 on: April 10, 2013, 09:07:15 PM »

I believe I have it figured out. And it has to do with another piece of hardware that is a big no-no on this forum. Ughhhh I guess it's time to redo my hot side piping again.

BTW, The car drives fine, just doesn't idle well. And when it warms up, o2 reg kicks back on at the STFTs are +25% at idle.
Logged
ddillenger
Hero Member
*****

Karma: +641/-21
Offline Offline

Posts: 5640


« Reply #8 on: April 10, 2013, 09:11:35 PM »

I believe I have it figured out. And it has to do with another piece of hardware that is a big no-no on this forum.

Does it make WHOOOOOOSSSSHHHHH noises?
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
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #9 on: April 10, 2013, 09:12:13 PM »

Does it make WHOOOOOOSSSSHHHHH noises?

DING DING DING

Maybe I should say fuck the DV and go all out with a blow through MAF
Logged
ddillenger
Hero Member
*****

Karma: +641/-21
Offline Offline

Posts: 5640


« Reply #10 on: April 10, 2013, 10:28:06 PM »

Meh.

How much power are you planning on? I wouldn't bother blow through unless it was necessary. Too much of a PITA. Keep it simple is my motto.
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
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #11 on: April 10, 2013, 10:32:00 PM »

Meh.

How much power are you planning on? I wouldn't bother blow through unless it was necessary. Too much of a PITA. Keep it simple is my motto.

Hoping for ~450whp this summer after I build my stroker engine. Shouldn't be too hard to plumb in my DV again though.
Logged
ddillenger
Hero Member
*****

Karma: +641/-21
Offline Offline

Posts: 5640


« Reply #12 on: April 10, 2013, 10:47:27 PM »

I have an AEG crank sitting in my garage. Just sayin'.
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
catbed
Sr. Member
****

Karma: +8/-2
Offline Offline

Posts: 300


« Reply #13 on: April 10, 2013, 10:54:39 PM »

I have an AEG crank sitting in my garage. Just sayin'.

I'll keep it in mind. I was just gonna snag one from a junkyard for cheap. Not tryin to lowball ya.
Logged
ddillenger
Hero Member
*****

Karma: +641/-21
Offline Offline

Posts: 5640


« Reply #14 on: April 10, 2013, 10:58:08 PM »

If you're local, you can have it. It's still in the shortblock so no damage.
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
Pages: [1] 2
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.021 seconds with 16 queries. (Pretty URLs adds 0.001s, 0q)