MTX-L readout discrepancy - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MSPNP MSPNP specific Megasquirt related discussion.

Reply
 
 
 
LinkBack Thread Tools
Old 11-11-2015, 01:05 PM   #1
Senior Member
Thread Starter
 
mmmjesse's Avatar
 
Join Date: Aug 2007
Posts: 568
Total Cats: 43
Default MTX-L readout discrepancy

Hey guys. Hoping you could help me figure out what is going on with My GEN2 PNP. I have an MTX-L guage with the 0-5v signal connected to the stock narrowband input. When i open and monitor with Tuner Studio, it is reading at .5 lower than the innovative gauge is. This is with the calibration set to the LC-1 if i recall correctly. If i go custom and manually enter the amounts that were included with the MTX-L instructions, it reads even further off. Has anyone experienced this before? What am i doing wrong here?
mmmjesse is offline   Reply With Quote
Old 11-11-2015, 08:07 PM   #2
Elite Member
iTrader: (7)
 
bahurd's Avatar
 
Join Date: Apr 2013
Location: Ohio
Posts: 2,124
Total Cats: 144
Default

Why do you have it connected to the narrowband input?
bahurd is offline   Reply With Quote
Old 11-11-2015, 09:06 PM   #3
Senior Member
Thread Starter
 
mmmjesse's Avatar
 
Join Date: Aug 2007
Posts: 568
Total Cats: 43
Default

Because that was one of the two options in the megasquirt manual. i have completely eliminated the stock O2 so i used the stock input to the ECU rather than the option port.

"There are two ways of connecting the controller to the MSPNP2. You can either connect the analog output to the pin labeled Oxygen Sensor input of the option connector, or you can cut and splice the oxygen sensor signal wire to the analog output. If you use this pin for wideband input, you must disconnect the stock oxygen sensor. Do not ground the oxygen sensor wire if you disconnect it; leave it completely unconnected and taped off if necessary (make sure it can't short to ground or anything else)."
mmmjesse is offline   Reply With Quote
Old 11-11-2015, 09:12 PM   #4
Ich verstehe nur Bahnhof
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,701
Total Cats: 319
Default

wideband to the MSPNP will be more beneficial in terms of tuning and logging and just general access to more information
psyber_0ptix is offline   Reply With Quote
Old 11-11-2015, 09:17 PM   #5
Goin Innnnn!!!
iTrader: (7)
 
Chooofoojoo's Avatar
 
Join Date: May 2014
Location: Denver, Co.
Posts: 460
Total Cats: 40
Default

I have my MTX-L Wired into the factory O2 input wire (just chopped off the wires off stock narrow band, wired my widebands output into the signal portion). Works without issue.

As far as MS calibration, I too had offset when using supplied data from innovate, as well as the LC-1 defaults. The output of the MTX-L is linear, so you can fiddle with the custom-wideband settings until it matches. If it's consistently off .5 across the whole range then just increase/decrease both the 0v and 5v readings .5 depending on which direction it's off. Should be about dead on then.

ALSO! Make sure your wideband grounds to the same place as the ECU with a dedicated ground wire. That makes sure there is no voltage offset between the MTX-L and the ecu.
Chooofoojoo is offline   Reply With Quote
Old 11-11-2015, 09:40 PM   #6
Elite Member
iTrader: (7)
 
bahurd's Avatar
 
Join Date: Apr 2013
Location: Ohio
Posts: 2,124
Total Cats: 144
Default

OP says "narrowband" so question is are you trying to display the narrowband output from the mtx-l (brown if I recall)?

If so relevant question is why?
bahurd is offline   Reply With Quote
Old 11-11-2015, 09:45 PM   #7
Goin Innnnn!!!
iTrader: (7)
 
Chooofoojoo's Avatar
 
Join Date: May 2014
Location: Denver, Co.
Posts: 460
Total Cats: 40
Default

Quote:
Originally Posted by bahurd View Post
OP says "narrowband" so question is are you trying to display the narrowband output from the mtx-l (brown if I recall)?

If so relevant question is why?
I read that as he has his MTX-L 0-5v wideband output wired through the cars existing O2 'narrowband' wire input. Aka he's feeding the mspnp his wideband signal through the stock O2 harness connector.

Thats exactly what I do and have had no problems once I corrected my offsets via the custom linear wideband option in Tuner Studio.
Chooofoojoo is offline   Reply With Quote
Old 11-11-2015, 09:51 PM   #8
Senior Member
Thread Starter
 
mmmjesse's Avatar
 
Join Date: Aug 2007
Posts: 568
Total Cats: 43
Default

Quote:
Originally Posted by Chooofoojoo View Post
I read that as he has his MTX-L 0-5v wideband output wired through the cars existing O2 'narrowband' wire input. Aka he's feeding the mspnp his wideband signal through the stock O2 harness connector.

Thats exactly what I do and have had no problems once I corrected my offsets via the custom linear wideband option in Tuner Studio.
This is correct. I will play with custom data to see where that gets me. I will also make sure my grounds are the same along with voltage input. Your input is greatly appreciated.
mmmjesse is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
OG Racing: Seats that Fit into a miata. Free shipping, In stock. OGRacing OG Racing 27 08-30-2016 03:35 PM
o2 sensor reading erratic Der_Idiot Hydra 10 12-07-2015 05:18 PM
WTB: 2001 NB Miata ECU Immobilizer and Key matching set. ajay842 WTB 2 11-19-2015 01:44 PM
HiRes 10g - GM IAT reads 300* F .one lane MSPNP 11 11-14-2015 11:09 PM
Pnp2 not seeing variable tps signal Tim18t MEGAsquirt 5 11-09-2015 05:06 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 06:19 PM.