Cus wrote:Red_Bullet wrote:I have 14point7 spartan 2 and Bosch LSU4.9. Running MS3Pro ECU. AFR seems stuck at 16.2
I have exactly the same setup, but with about 10,000km more on it, but I haven't looked at a log or a dashboard in 5000kms or so...
Because it's such a simple device, there's not really much to do in the troubleshooting department;
When you first power up the ECU/Car do you get the AFR at 13ish for 5 seconds, and then AFR of 16ish for another 5 seconds? (in my experience by the time the laptop connects to the ecu and updates the dash the initial reading only lasts a second before it goes to the higher reading)
If you don't get that, it might be the controller. If you do get the swing, I'd say it's possibly the Sensor - did you wire up the tempreature LED as well? (I didn't) It will blink different speeds depending on the temp the WBo2 is reporting, if it's always heating or cooling that could also indicate ... an error, somewhere... I don't know. That was a bad train of thought....
See if someone with a Bosch WBo2 wants to trade for 10 minutes
Cus thanks for your thoughts, I've ordered a new Bosch LSU 4.9 sensor. I pulled the original sensor out today and it is stuffed. Pins 3 to 4 (heater) read meg ohms, should be around 3 to 4 ohms. It does not heat up either, a dead giveaway! So the heater has failed, from the documentation this is bad thing and will cause the sensor to fail pretty quickly. In free air AFR is 16.2, with sensor in brake cleaner soaked rag it should read full rich. The AFR reading does not vary with this test. To answer your question regarding the LED, yes it is hooked up and working, indicating sensor too cold.(fast flash rate)
This is quite a long story, I think with the benefit of hindsight that the sensor has been failing gradually for some time. I was earlier running with AFR safety sensing ON, this causing ECU to cut engine due to an alleged lean condition. So, I did some VE analysis and richened up VE table to fix apparent lean condition. In hindsight I think it was never lean at all, just the failing sensor leading me and the ECU astray. (Garbage In Garbage Out)
One thing that I have since noticed in the 14point7 spartan2 manual is that the 12 volts should not be applied to the controller until the engine is started. I have it powering up with ignition on, so it can incorrectly heat the sensor before the engine starts. Apparently condensation can damage a pre heated hot sensor when the engine starts.
Now I need to figure out the best way to only apply power to the controller only after the engine has started. No obvious outputs are jumping out at me screaming "use me" from the megasquirt manual, Maybe I'm thinking that using a voltage sensing circuit might be the go, something like once the voltage goes over 13.2 V, then pull a self-holding relay in to power up Wide -band controller.
What have other people done? I Gotta pull out the mx5 schematics to see if there is something obvious there, All I need is a signal to say "engine running" something like "sync" from the MS assigned to an output would be good to pull a relay in to power up WB controller.
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