Wideband read differently on your MS? This might be why. - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 04-21-2011, 06:15 PM   #21
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hmm my AEM is off by .1-.2 from MS to the AEM, currently its grounded to ECU adapter harness, but I'm gonna try firewall and parrlel wire running with it as well
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Old 04-21-2011, 06:20 PM   #22
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Originally Posted by Techsalvager View Post
hmm my AEM is off by .1-.2 from MS to the AEM, currently its grounded to ECU adapter harness, but I'm gonna try firewall and parrlel wire running with it as well
My AEM is off by this same amount
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Old 05-05-2011, 05:24 PM   #23
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Originally Posted by JasonC SBB View Post
I shake my head whenever I see newbie-engineer errors such as what AEM has done to their gauge and what I found when hacking their miata ECU.
What did you find by hacking their miata ECU? Anything that should/could easily be "fixed" by the end user?
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Old 05-05-2011, 06:01 PM   #24
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I've tried several times to resolve the problem with my car; by changing grounds, adjusting the MS's AFR calibration, and even bought a 2nd wideband that did the same thing. My gauge is reading almost a 1 point discrepancy, gauge reads richer than MS.

I just wanted to clarify... In the event that there is a discrepancy between the AEM gauge and MS, it is assumed that the AEM gauge face is correct. Is that right?

I finally gave up on actually fixing the issue and adjusted my target tables a point leaner than they should be. I'd hate to think I'm tuning to a 12.5 afr at wot.
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Old 05-05-2011, 06:22 PM   #25
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A multimeter tells the tale. MS has an offset.
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Old 05-05-2011, 09:12 PM   #26
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Originally Posted by TurboTim View Post
What did you find by hacking their miata ECU? Anything that should/could easily be "fixed" by the end user?
Bunch of wimpy confused ground connections between the various ground pins on the connectors and the circuitry. I beefed em up with some 20 gauge wire. Fixed a problem where there was a 0.2V offset on the MAP sensor reading, which was worth almost a 10 kPa error (lame!).
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Old 01-25-2012, 10:16 AM   #27
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Pulling a Jesus on this thread, but I now have the same issue. The discrepancy in my readings is of ~1.3 points. Which gauge reads correct? I dont see an answer for Pdexta. My WB is a PLX300 btw.
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Old 01-25-2012, 10:48 AM   #28
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Originally Posted by buffon01 View Post
Pulling a Jesus on this thread, but I now have the same issue. The discrepancy in my readings is of ~1.3 points. Which gauge reads correct? I dont see an answer for Pdexta. My WB is a PLX300 btw.
I solved my problem by running the ground to the same source as my ECU. It still wasn't perfect but it was damn close. I also suggest compensating for the reading in your AFR target table.
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Old 01-25-2012, 11:03 AM   #29
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DMM's solve all voltage offset problems...
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Old 01-25-2012, 11:22 AM   #30
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I recently soldered all ground wires to ring connectors (rather than crimping only) and suddenly, the old offset in my WBO2 is gone. :wiggle:
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Old 01-25-2012, 12:26 PM   #31
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I solved my problem by running the ground to the same source as my ECU. It still wasn't perfect but it was damn close. I also suggest compensating for the reading in your AFR target table.
Well, then who is the correct reading? TS or WB?

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Originally Posted by Braineack View Post
DMM's solve all voltage offset problems...
WBO2 101 here, how do I measure voltage differences. Also how to I "offset"... is there a table for this. I just went throught TS and I couldn't find such thing. My WB does not have the calibration software LC-1s have.

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I recently soldered all ground wires to ring connectors (rather than crimping only) and suddenly, the old offset in my WBO2 is gone. :wiggle:
You're so gangsta

Thanks
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Old 01-25-2012, 12:47 PM   #32
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WB is the correct reading
if there is different reading in TS thats because of a voltage difference from the output of the wideband to the megasquirt.
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Old 01-25-2012, 12:54 PM   #33
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Originally Posted by Techsalvager View Post
WB is the correct reading
if there is different reading in TS thats because of a voltage difference from the output of the wideband to the megasquirt.
Okay, thanks. I now remembered that when I had the ground to a chassi port the difference was minimal. This time I kept the cable in the cabin. Time to re-ground.
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Old 01-25-2012, 01:09 PM   #34
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You need to measure the voltage input into the MS. But you need to reference it against what the PLX is sending.

for exmaple, if you know the PLX should be at 5v and the MS is only getting 4.5v, you can recalibrate the MS to properly read and interperate the signal.
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Old 01-25-2012, 01:29 PM   #35
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Quote:
Originally Posted by Braineack View Post
You need to measure the voltage input into the MS. But you need to reference it against what the PLX is sending.

for exmaple, if you know the PLX should be at 5v and the MS is only getting 4.5v, you can recalibrate the MS to properly read and interperate the signal.
How? is there a voltage/afr table somewhere that I overlooked?

Me is a
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Old 01-25-2012, 01:35 PM   #36
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oh youre still on one of those acient msI machines.
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Old 01-25-2012, 01:40 PM   #37
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Originally Posted by buffon01 View Post
Which gauge reads correct?
When there is a conflict between what is seen on the gauge itself and what is displayed by the ECU, always trust the gauge, and assume that there is a calibration or ground offset problem.

All else being equal, the analog ground for the wideband controller should always be connected to the same ground as the ECU uses for its analog sensors. Ideally, the wideband ground will actually be connected directly to a ground pin at the ECU.

Why not give it the "best" ground possible? Because if the ECU itself is experiencing any kind of ground offset, you want the wideband controller to experience the same offset. That way, the two devices are "in sync" with one another. On my cars, I have always either spliced into an ECU ground wire, or double-crimped the wideband analog ground directly into one of the ECU's own ground pins.

In cases where the wideband system has a seperate ground for the heater, this can be run directly to the engine. This is contrary to Innovate's instructions, however as Ben stated earlier, I believe they state this only to make the instructions simpler for people.
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Old 01-27-2012, 02:00 PM   #38
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Originally Posted by Braineack View Post
oh youre still on one of those acient msI machines.
No, I have MSII.

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Originally Posted by Joe Perez View Post
When there is a conflict between what is seen on the gauge itself and what is displayed by the ECU, always trust the gauge, and assume that there is a calibration or ground offset problem.

All else being equal, the analog ground for the wideband controller should always be connected to the same ground as the ECU uses for its analog sensors. Ideally, the wideband ground will actually be connected directly to a ground pin at the ECU.

Why not give it the "best" ground possible? Because if the ECU itself is experiencing any kind of ground offset, you want the wideband controller to experience the same offset. That way, the two devices are "in sync" with one another. On my cars, I have always either spliced into an ECU ground wire, or double-crimped the wideband analog ground directly into one of the ECU's own ground pins.

In cases where the wideband system has a seperate ground for the heater, this can be run directly to the engine. This is contrary to Innovate's instructions, however as Ben stated earlier, I believe they state this only to make the instructions simpler for people.
Thank Joe
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Old 02-22-2012, 11:30 PM   #39
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Logworks is the most accurate correct? I have TunerStudio and LogWorks displaying within 0.1 of each other, but my analog gauge is reading ~0.3/0.4 off. My grounding is superb. Thanks WB gurus.
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Old 02-23-2012, 09:46 AM   #40
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so alter the output voltge range on that channel until it matches better.
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