MSPNP not reading AEM failsafe WB - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MSPNP MSPNP specific Megasquirt related discussion.

Reply
 
 
 
LinkBack Thread Tools
Old 04-03-2013, 04:10 PM   #1
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default MSPNP not reading AEM failsafe WB

I installed a 1st gen MSPNP 9093 in a friend's '90 (intercooled greddy with RX-8 425s, if that makes a difference) using an AEM failsafe WB/boost gauge combo, cause he liked the idea of less gauges.

AEM Electronics Wideband Failsafe Gauges 30-4900 - SummitRacing.com

It's reading correctly on the gauge, and it is kinda cool, cause the outer ring can display in LEDs either boost or AFR, and the inner readout can display either boost or AFR. Neat!

However, we CANNOT get the MSPNP to read ANYTHING. Both Tunerstudios and Megatune are configured to be reading a AEM uego, and both are stuck on 9.72 afr (gauge 2 is stuck on 8.84 if that matters). We have tried using both the center connector pin 10 WB input, and using the stock NB for WB input. Either way, the gauge NEVER budges.

Note: the gauge also has a 0-5v MAP output.

I've used my multimeter and confirmed that the white wire delivers a 0-5v signal, so does the yellow MAP output wire. Neither have made the gauges in TS or MT budge.

I recently took it apart to replace the transistor that blew when the PO left the ST fuse in. The fuel pump now briefly primes upon powering up as it should. I did notice the ECU was modified to accept a VTPS. These modifications were made:


What am I missing?
Attached Thumbnails
MSPNP not reading AEM failsafe WB-jumper_mods.jpg  
curly is offline   Reply With Quote
Old 04-03-2013, 04:16 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,823
Total Cats: 1,781
Default

are you using the correct pin 10?

I'm suggesting you counted from the wrong side/row.
Braineack is online now   Reply With Quote
Old 04-03-2013, 04:17 PM   #3
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Here are the gauge's wiring instructions. As you can see, the brown wire is setup to output a NEGATIVE 0-5v, and according to the instructions, it appears that an AEM ECU uses both the -5-0v signal (brown) and 0-5v signal (white) in combination to get a clear signal. Perhaps to filter out noise?

According to the instructions, "The brown wire should be connected to an analog ground input for best results. If the [MS] does not have an analog ground input, the brown wire should be connected to a sensor ground. If no sensor ground is available, the brown wire should be connected to a power ground."

So, since the MS doesn't have a analog ground input, I take that as saying the brown wire should be grounded. During our testing the brown wire was at one point hooked into the MS, would this blow anything up?

Our final testing had the brown wire grounded to the chassis, and we were trying everywhere to get the white wire to send a signal to the MS. Wasn't happening.


Attached Thumbnails
MSPNP not reading AEM failsafe WB-33524a59-2388-4ef3-aada-13b55f0941b7-15280-000007c931dad0ed_zps27c52d50.jpg   MSPNP not reading AEM failsafe WB-bb6b2d7a-6a3a-4723-bc51-fac146fee953-15280-000007c93403ecc8_zps3a9b846d.jpg  
curly is offline   Reply With Quote
Old 04-03-2013, 04:22 PM   #4
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

In this photo, it is the bottom row, 2nd one from the left, correctly? Top row is 1-8, bottom row is 9-16?

And, even if I were using the incorrect wire, why would the stock NB wire not work? Is that why there is a AFR and AFR2 gauge? We were looking at both during all the testing.

Attached Thumbnails
MSPNP not reading AEM failsafe WB-f6c2f688-f42b-4a6e-86b1-051d78b7a8c4-15280-000007cb4d25d711_zps2293a1be.jpg  
curly is offline   Reply With Quote
Old 04-03-2013, 04:23 PM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,823
Total Cats: 1,781
Default

brown wire should go to a black/lt green wire.
Braineack is online now   Reply With Quote
Old 04-03-2013, 04:48 PM   #6
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,823
Total Cats: 1,781
Default

Quote:

The top pins are numbered 1 through 8, left to right, and the bottom pins are
numbered 9 through 16.
I'm acutally not sure if that's looking at the connector as pictured, or from the backside at the wires. Easiest check would be to check with a multimeter, but less smarter people than you have figured it out.
Braineack is online now   Reply With Quote
Old 04-03-2013, 05:01 PM   #7
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Quote:
Originally Posted by Braineack View Post
brown wire should go to a black/lt green wire.
So the negative output signal should go to the black/lt green wire of the MS? Is it easier to just vampire tap into the connector by the MS, or go through the firewall to the NB o2 wire?

Quote:
Originally Posted by Braineack View Post
I'm acutally not sure if that's looking at the connector as pictured, or from the backside at the wires. Easiest check would be to check with a multimeter, but less smarter people than you have figured it out.
Actually, I looked at the back of the connector, and grabbed the 2nd from the left of the bottom row.

Using the description I typed in post #4, that would be pin 15.
curly is offline   Reply With Quote
Old 04-03-2013, 05:15 PM   #8
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Oh, and a log showing the stoic 9.72 AFR.
Attached Files
File Type: msl adamsfirstdatalog.msl (867.4 KB, 88 views)
curly is offline   Reply With Quote
Old 04-04-2013, 12:55 PM   #9
Junior Member
iTrader: (2)
 
Join Date: Oct 2011
Location: Chicago Il
Posts: 111
Total Cats: 2
Default

check out this diagram for how to count the pins. I _think_ you're doing it backwards. Try counting from the back of the plug.

Attached Thumbnails
MSPNP not reading AEM failsafe WB-image027.jpg  
akbloom is offline   Reply With Quote
Old 04-04-2013, 12:59 PM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,823
Total Cats: 1,781
Default

Quote:
Originally Posted by akbloom View Post
check out this diagram for how to count the pins. I _think_ you're doing it backwards. Try counting from the back of the plug.

if that's the case then:





Quote:
So the negative output signal should go to the black/lt green wire of the MS? Is it easier to just vampire tap into the connector by the MS, or go through the firewall to the NB o2 wire?
It's not a "negative output," as much as it's a sensor ground. The Black/Lt green wires are sensor grounds, meaning all the sensors (TPS, CAS, ETC) are grounded THROUGH the ECU and not directly to the frame/chassis/block. It must be connected in order to recieve data through the two, white and yellow, outputs.
Attached Thumbnails
MSPNP not reading AEM failsafe WB-16pinconnector.jpg  
Braineack is online now   Reply With Quote
Old 04-04-2013, 03:51 PM   #11
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Ok, so I'll tap the brown into the black/green wires, and according to your expertly drawn wiring diagram above, I was using the correct pin 10. I still feel like the gauge should have budged.

Any other ideas?
curly is offline   Reply With Quote
Old 04-04-2013, 03:53 PM   #12
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,823
Total Cats: 1,781
Default

the controller is displaying the correct but MS is not showing correct, correct?
Braineack is online now   Reply With Quote
Old 04-04-2013, 04:26 PM   #13
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Yes, controller is reading awesome AFRs for a turbo car, smoothly from mid 15s to mid 11s in boost. Car feels amazing.

MS reads 9.72 and not a .0000000001ths change in all our testing.
curly is offline   Reply With Quote
Old 04-04-2013, 04:28 PM   #14
Cpt. Slow
Thread Starter
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Here's the current .msq if that helps.

I've changed the TS project properties to AEM's wideband, and the Exhaust Gas Settings to wideband. In MegaTune I used the configurator to set it to AEM's gauge, and changed the same settings in Exhaust Gas Settings as above. AFAIK, those are the only software related changes required.
Attached Files
File Type: msq no blip.msq (39.4 KB, 97 views)
curly is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 05:11 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
1996 Turbo Build Goldwar DIY Turbo Discussion 2 09-29-2015 10:20 AM


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 02:58 PM.