MEGAsquirt A place to collectively sort out this megasquirt gizmo

MAP behaves oddly during Overrun..

Thread Tools
 
Search this Thread
 
Old 04-01-2008, 07:50 PM
  #1  
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,046
Total Cats: 6,607
Default MAP behaves oddly during Overrun..

I remember a little while ago some people mentioning that they sometimes observed MLV to populate very strange values into certain cells. I myself have seen this occur frequently in the 100kpa area, and I figured out why.

It seems that sometimes, but not always, while I am in overrun (coasting in gear) my MAP value jumps to exactly 100 kpa and stays there for a moment, then reverts back to reality. I have seen this not only in the logs, but also on the gauge display in Megatune. It's never done it while I'm on the throttle, and oddly it does not turn the fuel back on when it happens.

A full log is attached, but here's a screenshot of a typical event:




Has anyone ever seen such a thing before?
Attached Files
File Type: zip
datalog200803271608.zip (366.8 KB, 43 views)
Joe Perez is online now  
Old 04-01-2008, 11:28 PM
  #2  
Senior Member
iTrader: (5)
 
The_Pipefather's Avatar
 
Join Date: Nov 2007
Location: Troy, MI
Posts: 854
Total Cats: 14
Default

You know, I am neither turbocharged, nor at sea level, yet I see this today:

The_Pipefather is offline  
Old 04-02-2008, 12:49 AM
  #3  
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,091
Total Cats: 7
Default

I found 4 similar events.






cjernigan is offline  
Old 04-03-2008, 11:54 AM
  #4  
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,046
Total Cats: 6,607
Default

This morning I turned off Overrun and logged. The exact same thing happened- both in the log and on the gauge display. And again, it seemed not to impact the actual fueling- it's as though this is a display / logging artifact only.

Damned odd. I've started a thread over at MSExtra, which so far has failed to gather much interest. Seems that folks over there don't really care an awful lot about debugging... http://www.msextra.com/viewtopic.php?p=183865#183865
Joe Perez is online now  
Old 04-03-2008, 11:56 AM
  #5  
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,091
Total Cats: 7
Default

Originally Posted by Joe Perez
This morning I turned off Overrun and logged. The exact same thing happened- both in the log and on the gauge display. And again, it seemed not to impact the actual fueling- it's as though this is a display / logging artifact only.

Damned odd. I've started a thread over at MSExtra, which so far has failed to gather much interest. Seems that folks over there don't really care an awful lot about debugging... http://www.msextra.com/viewtopic.php?p=183865#183865
I guess that is why RB26 has jumped up and helped start the DIY EFI project?
cjernigan is offline  
Old 04-03-2008, 12:27 PM
  #6  
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,332
Total Cats: 67
Default

I haven't seen this behavior on our own tests, so I'd encourage the others who have to post their similar logs in Joe's thread on MSExtra.com. The more data the developers have, the more they'll have to go on.
__________________
Matt Cramer
www.diyautotune.com
Matt Cramer is offline  
Old 04-03-2008, 12:42 PM
  #7  
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,091
Total Cats: 7
Default

I'll upload my data as well to msextra.
cjernigan is offline  
Old 04-03-2008, 05:28 PM
  #8  
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,091
Total Cats: 7
Default

Hey guys.
In the meantime until we find a solution to this problem we can use a custom filter in MLV under the advanced options. Just click on "custom filter" and then enter this [MAP] = 100 && [TP] = 0
That will filter out all of the spikes where TP = 0 and MAP = 100. I just tried it out and it works great. Instead of it adding 20 extra VE in my 100 kpa row it made accurate adjustments.
cjernigan is offline  
Old 04-03-2008, 07:38 PM
  #9  
Senior Member
iTrader: (5)
 
The_Pipefather's Avatar
 
Join Date: Nov 2007
Location: Troy, MI
Posts: 854
Total Cats: 14
Default

Or if you dont have a TPS you can say [MAP]=100 and [O2]=4.99 too, isn't that right?
The_Pipefather is offline  
Old 04-04-2008, 01:06 AM
  #10  
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,046
Total Cats: 6,607
Default

Originally Posted by cjernigan
In the meantime until we find a solution to this problem we can use a custom filter in MLV under the advanced options. Just click on "custom filter" and then enter this [MAP] = 100 && [TP] = 0
Genius! At least someone has been reading and paying attention. That works nicely.
Joe Perez is online now  
Old 06-06-2008, 10:55 AM
  #11  
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,046
Total Cats: 6,607
Default

The problem has been properly solved by Keithg: http://www.msextra.com/viewtopic.php...187749#p187749

Short version: it's the kpafactor4250.inc file in the /mtCfg/ directory. The one which comes with MegaTune only has valid values down to 12 kPa, and considers anything below that to be a sensor error. The one which comes in the /hr10x/src/ directory (and is compiled into the bin) has valid data down to 10 kPa. So, every time the MAP voltage drops to ~.05v or less, even though the MS itself is able to interpret this properly, MT considers it an error and throws a 100.

Copy the version of the file that came with the hr distribution into /mtCfg/, and the problem is no more!
Joe Perez is online now  
Old 06-06-2008, 10:58 AM
  #12  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

shoulda gone hydra, son.
hustler is offline  
Old 06-06-2008, 11:58 AM
  #13  
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,338
Total Cats: 573
Default

Originally Posted by hustler
shoulda gone hydra, son.
right because hydra would just say "sorry, we cannot fix your version of the software. do not run below 12kpa"
y8s is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
04-12-2021 04:21 PM
ihiryu
MEGAsquirt
33
10-08-2015 04:56 PM
MiataGarage
Engine Performance
5
09-29-2015 11:04 PM
brandonbkd
MEGAsquirt
0
09-28-2015 11:52 PM



Quick Reply: MAP behaves oddly during Overrun..



All times are GMT -4. The time now is 11:36 AM.