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Throttle Position Issue

PostPosted: Sun Sep 29, 2019 6:15 pm
by cameron
Hi All,
Have an issue with a contact less hall effect TPS sensor on a cable throttle carburetor Formula Ford. Image of setup as attached. Issue is that the throttle position will read a negative % valve when off throttle (as pictured) and gives an inaccurate throttle pickup trace, Any suggestions on how to fix this.
Dash Is a Motec Sports dash
2008 Mygale Formula Ford
Data from qualifying at Pukekohe New Zealand

Re: Throttle Position Issue

PostPosted: Mon Sep 30, 2019 8:05 am
by David Ferguson
The spikes in your data look like a wiring issue. that is what intermittent connections look like. It could also be interference with something like a radio transmission.

Check other sensors using 5V, to see if it could be the 5V power that is being shorted. If so, they will usually show spikey data at the same time.

Re: Throttle Position Issue

PostPosted: Mon Sep 30, 2019 10:38 am
by Stephen Dean
Hi Cameron,

As per Davids email, I would be looking at the wiring and other sensors, to make sure that they are not pulling the 5V+ feed down.

Re: Throttle Position Issue

PostPosted: Tue Oct 01, 2019 10:03 am
by cameron
Thank you for the advise, All the other sensors seem to be reading correctly via the logged data but I will now start the process of checking and testing all the wiring and sensor outputs.

Thanks again cam

Re: Throttle Position Issue

PostPosted: Tue Oct 01, 2019 12:08 pm
by AdamW
The photo is not a great one, but if I'm looking at it correctly, that bracket that is holding the tps sensor body looks a bit flimsy. How much can it flex? How much end float is there in the throttle shaft? Is the magnet still tight on the shaft? Those contactless sensors need the air gap to remain fairly constant.