Lean spike on tip-on, not due to lack of AE - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 10-06-2015, 12:09 PM   #1
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default Lean spike on tip-on, not due to lack of AE

*tip-in, not tip-on

I've had trouble finding anyone else with this same problem, but I'm hoping it a setting I've overlooked in TS. This problem is worst when shifting under high boost, theres a pretty significant lean spike that can last a good half a second in some cases. I've tried increasing AE, all it does is make it go even richer AFTER the spike. Its almost as if there is a significant lag coming from the AFR gauge. Additionally, the car will (sometimes) peg out lean but (always) fall on its face when you try to rev it from idle with anything but super gentle throttle applictaion (low tpsdot). I feel these two issues could be related. Datalog/Tune attached

I've tried:
-Increasing AE
-Richening lower right of VE table where shifting occurs
-using 25% mapdot instead of 100% TPSdot
-Changing the rpm range for AE

The car:
1990 miata with '96 1.8 swap
homeade log mani with ebay t3/t4
DIYPNP
1000cc deatchwerks
stock fp, fuel rail, etc
stock ignition
E85
1.8 vtps

Heres a screenshot of the lean spikes during an 1/8 mile pass


Heres it coughing/falling on its face when tip in from idle
Attached Thumbnails
Lean spike on tip-on, not due to lack of AE-leanspikes_zpstnrkbvbp.jpg   Lean spike on tip-on, not due to lack of AE-cough_zps1vlwluc3.jpg  
rmonheim is offline   Reply With Quote
Old 10-06-2015, 01:06 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,842
Total Cats: 1,787
Default




Attached Thumbnails
Lean spike on tip-on, not due to lack of AE-80-not_enough_19adbbe160ef1eacb7b74c683247e5a44b589859.png   Lean spike on tip-on, not due to lack of AE-80-too_much_e78aa1ef24af490ccdf92ce1eddb455b3e5e6187.png  
Braineack is offline   Reply With Quote
Old 10-06-2015, 01:42 PM   #3
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default

So does this mean I need to mess with the rpm scaling moreso than the AE table? Rpm scaling reduces AE at high Rpms, so if I turn up AE to compensate, it will make off idle worse, correct?
rmonheim is offline   Reply With Quote
Old 10-06-2015, 01:50 PM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,842
Total Cats: 1,787
Default

on the first log it looks like your AE enrichments barely added any fuel, this made it spike lean. (spiking lean isn't so "bad" as long as you dont feel it).

the second log it looks like your AE enrichments DUMPED in fuel, and made the motor bog down, then it looks like you blew out spark or something.


what do your AE settings look like?
Braineack is offline   Reply With Quote
Old 10-06-2015, 01:59 PM   #5
Senior Member
iTrader: (1)
 
Join Date: Dec 2010
Location: Farmington Hills, MI
Posts: 873
Total Cats: 93
Default

Increase AE at 770 tpsdot, decrease AE at 502 tps dot. Repeat. Hit those values at high rpm, hit those values at low rpm. Is the issue still there? Is the issue only at high rpms or low rpms? This is what data is for..
acedeuce802 is online now   Reply With Quote
Old 10-06-2015, 02:12 PM   #6
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default

I cannot feel the lean spike while shifting, I was curious if it was dangerous or not. This hesitation happens at all tpsdot off idle. The only time you can really feel anything is when you are blipping the throttle at lower rpms (below 4500 or so). I've tried playing the AE values in the table quite a bit, maybe I just need to do it more. If a small lean spike during shifting isnt an issue, I suppose I could just tune it to feel right while hitting the throttle under no load.

Attached Thumbnails
Lean spike on tip-on, not due to lack of AE-ae%2520settings_zpsyxl4etsa.jpg  
rmonheim is offline   Reply With Quote
Old 10-06-2015, 02:20 PM   #7
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,842
Total Cats: 1,787
Default

your TPS threshold is 300 %/sec...

your TPS log also shows it going into negative values. Unsure how one can achieve a -71% Throttle Position...
Braineack is offline   Reply With Quote
Old 10-06-2015, 02:25 PM   #8
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default

Ok, should I try raising it?
rmonheim is offline   Reply With Quote
Old 10-06-2015, 02:25 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,842
Total Cats: 1,787
Default

lol.
Braineack is offline   Reply With Quote
Old 10-06-2015, 02:27 PM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,842
Total Cats: 1,787
Default

also what firmware are you using? I thought they got rid of "added ms" for "added %" like 5 years ago.
Braineack is offline   Reply With Quote
Old 10-06-2015, 03:02 PM   #11
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default

I'm fairly sure the DIYPNP is running 3.3.3. I believe this was the most up to date version when I put it together like 6 months ago. %/s would make things a lot easier. It looks like they've come out with 3.4.0 since then.

We've had issues with tps being noisy, going negative, etc. Didn't think it was really an issue as long as TPSdot works when you tip in

I'll go ahead and mess with tpsdot threshold since apparently it's way off (base map has 200%?). You sure don't want to make this easy
rmonheim is offline   Reply With Quote
Old 10-06-2015, 03:06 PM   #12
Senior Member
iTrader: (1)
 
Join Date: Dec 2010
Location: Farmington Hills, MI
Posts: 873
Total Cats: 93
Default

You want the tpsdot threshold as low as possible. As long as you don't get noise above the threshold. I think mine is around 5, if I remember correctly.
acedeuce802 is online now   Reply With Quote
Old 10-06-2015, 03:11 PM   #13
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default

Thank you. It seems that's unrelated to the stumbling issue that happens above 300%/s

This is not a street car in any way, so I really don't care what it feels like at low tpsdot. Just trying to get it to rev up (usually 500%/s +) to the launch control limiter without it coughing


Edit: this is off the diyautotune site: "Note that MS3 has a slightly different PW adder - the MS3 uses a percentage of Required Fuel instead of an absolute number, making the AE stay the same when you change injectors. More about this later"

I have DIYPNP which is MS2...

Last edited by rmonheim; 10-06-2015 at 03:52 PM.
rmonheim is offline   Reply With Quote
Old 10-06-2015, 05:59 PM   #14
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

I bet the VE table isn't tuned properly either.


You need to tune it in the higher load areas at idle speeds, (I drive around manipulating the throttle whilst left foot braking to keep the rpms low. if those aren't right you'll never get crisp throttle response off idle irrespective of what you do with AE
richyvrlimited is offline   Reply With Quote
Old 10-06-2015, 06:49 PM   #15
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,660
Total Cats: 1,559
Default

Did you calibrate the TPS?
sixshooter is offline   Reply With Quote
Old 10-06-2015, 07:32 PM   #16
Newb
Thread Starter
 
Join Date: Apr 2012
Posts: 15
Total Cats: 1
Default

TPS has been calibrated, although it has been awhile. I recall it was still occasionally giving negative values right after calibration.
rmonheim is offline   Reply With Quote
Old 10-07-2015, 12:23 AM   #17
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,660
Total Cats: 1,559
Default

It is possible to rotate the TPS to change the base numbers for open and closed.
sixshooter is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
DIYPNP problem PA0 VICS output spidy MEGAsquirt 7 09-24-2015 04:14 PM
Miata Limo! ennjay General Miata Chat 2 09-17-2015 08:04 AM
DIYPNP Won't Stay Running huesmann MEGAsquirt 19 09-16-2015 08:11 PM
using 2002 ECU on 1990 Miata btabor ECUs and Tuning 12 09-14-2015 04:45 PM
AFR Not showing anything eunosgippa MEGAsquirt 0 09-09-2015 06:19 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:10 PM.