Wideband never reading lean

[festy]

Had a strange problem today, not sure yet if it's a hardware fault or not at this point so wondering if anyone had seen something like this before?

A first gen 14point7 Spartan for some reason is now only reading AFRs < 14.7 with OSE 12P 1.1.2
The cal is correct (0v=10, 5v=20) and I was using the bundled 3 bar Petrol ADX, but all the logs looked like this:

The simulated NB doesn't appear to be doing much in the logs, so I'm leaning more towards a hardware fault than a software glitch. Could this a sign of a failing or dirty sensor?

[Jayme]

good question, but my spartan2 has a similar problem brand new out of the box. it calibrates correctly during bootup sequence but when its running it pegs at 10.3:1 and only ever goes a little bit leaner than that during decel.... emailed alan, waiting on a response still.

[Dylan]

First thing I thought was how's the start up sequence look?
Jayme is ok but how's your's Festy? I have spartan and it's been trouble free.

[festy]

What is the startup sequence meant to look like?
I can't see any reference to it in the Spartan user guide (http://cdn.shopify.com/s/files/1/0189/1 ... l.pdf?2057) but I looked through some of the logs I collected yesterday and found this - it tops out at 14.6:

spartan_start.jpg (34.29 KiB) Viewed 7124 times

After that sequence, with the engine off the indicated AFR stayed at 14.6 for 90 seconds then slowly dropped by 0.1 every 10 seconds down to 12.5 over the next 5 minutes.

The NB goes pretty much straight to 0.45v and stays there regardless of the AFR with only a tiny ripple here and there, no cross counts even when the AFR jumps from 11 to the 14.6 ceiling so from that I think it's not a problem with the ECU analogue input (i.e. the ECU is seeing a max 2.5v when the Spartan is outputting higher) because if that was the case there should still be cross counts on the NB so I think it's most likely a fault with the Spartan?

I've found *one* instance of a higher than 14.6 AFR in the logs - a stall due to a faulty MAP sensor logged a momentary 19 AFR, which I guess rules out it being an issue with the logging but not much more.

[vlad01]

confirm what the output voltage is with WB in the air and not connected to anything , then check again with it connected tot he ECU. it should sit at 5.00V in open air whilst operating with nothing connected to the output.

[festy]

The car is an hour's drive away, otherwise I'd be checking the voltage readings etc but the dodgy NB output makes me think it's probably not an ECU issue.
And with it appearing to work in the 0v-2.5v range but not at all in the 2.5v-5v range, I'm leaning more towards a controller issue than a faulty sensor.
I've fired off an email to Alan @ 14point7, hopefully he can shed some light on the matter...

[Dylan]

Once the controller is first powered up it outputs 13.3 then 16.6 afr.
I use that to calibrate the 0v and 5v settings in the wideband scalars.

I ended up with some big offsets with mine. Something like 9afr for 0v and 22afr for 5v.
The narrow band output on mine is useless.

[festy]

Thanks, I plotted the proper startup sequence against the log.
There doesn't appear to be a linear offset:

plots.jpg (12.8 KiB) Viewed 7107 times

This Spartan didn't need any significant offsets previously, and the simulated NB used to look good with plenty of cross counts.
It's been installed (and powered) in the car for about a year since I last logged it, but don't think any logs were taken between then and yesterday.
I upgraded from 12P 1.1.1 to 1.1.2 by migrating the cal yesterday, and afterwards I confirmed that the wideband 0v and 5v scalars were still 10 and 20 AFR as they previously were.

[delcowizzid]

sensor is probably just cactus

[vlad01]

Once the controller is first powered up it outputs 13.3 then 16.6 afr.
I use that to calibrate the 0v and 5v settings in the wideband scalars.

I ended up with some big offsets with mine. Something like 9afr for 0v and 22afr for 5v.
The narrow band output on mine is useless.

mine ended up at 10.1 and 21.something. the NB on mine works excellent! Not sure why yours wouldn't be working?

actually the sequence goes 10, 13.3, 16.66 then actual readings.