MicroSquirt.com read only forum (Jan.15,2018)

My TPS had been working fine but now it's only changing at a rate of about 1%/second or less. Measuring the TPS input pin directly shows that the TPS is providing a quick varying signal and the min/max TPS settings appear to be correct. Anyone have any ideas what would cause this? Seems like it may have coordinated with my turning on EAE, but I'm back on AE only now. For the sake of making the car run, I've changed to a MAP-based AE and it works but it's not optimal. Any help would be much appreciated.

Any chance you've turned up the TPS lag factor too much? Posting an MSQ may shed more light on things.

Hey Matt-

the TPS delay is set to the default of 50, so I don't think that's it.

I was looking at a log from a track day this past weekend and happen to select TPS as I was checking some data. It's flat at near zero for pretty much the whole time, but at one point the TPS fluctuated for a bit, then went back down near zero. I'll grab the tuning laptop tomorrow and upload the log for reference.

Also, I went back and measured the voltage at pin 13 again with someone running the throttle. I'm seeing about .6V closed and 4.6V at wot, which seems reasonable. This is the same microsquirt module that blew a few diodes on an over-voltage or reverse-voltage spike a few weeks ago (Kevin fixed it). I hadn't paid attention to this issue before, so I'm not sure when the TPS stopped working, but I suppose the TPS circuit may have been susceptible to the same spike?

Thanks for your help-
Dave

It's possible the circuit is damaged; you can try following the signal through the circuit and see if it's getting pulled to ground somewhere.