[Trevor]

Originally Posted by svx_commuter

Hi Trevor ,

When my TPS went bad, had a code, I wanted to know what happened to this thing. So I made a 2" x 3" piece of plywood and mounted the tps in the corner with an arm attached to it. Then I marked off equally spaced angle marks about 2' from the center of rotation. I was able to put it back in the same exact position and check readings. I also cleaned it several times and checked to see if that worked. I also checked the new sensor the same way on the board.

They wear out. I think the conductive plastic is not very thick and the wear makes it thinner.

Take care of that SVX,

John

Hi John,

Quite a long time ago I posted the following without result. I now wonder if you could be the man to do some experimenting, provided that you have a faulty TPS on hand.

Tip For Checking the TPS

As a result of a thread involving a faulty throttle position sensor, a possible handy man method of a reliable fault finding method has come to mind, but experimentation is required.

Many will have been annoyed by audio gear which has a noisy volume control. Has the penny dropped ?????!!!!!

As most will be aware the TPS comprises a potentiometer, consisting off a conductive plastic insulating element around which traverses a wiping contact. Dirt on the surface can interrupt contact, as can a faulty element or inadequate pressure. It can be difficult to detect intermittent contact as the wiper is turned, due there being little time to register a measurement. The response time of a typical ohmmeter or voltmeter is inadequate. A meter with a bar graph or an oscilloscope is required. The handyman does not normally have access to this sort of gear.

Hook up the TPS with a capacitor of a few mfds in series with a torch cell, and stick the output across the input of an audio amplifier. Anything will do, guitar amp, walkman, whatever. In fact even headphones without amplification may work. Turn the TPS and listen to the music ?! A nice rushing sound as the unit is turned will be good music. Nasty static will be bad news.

This is simply an idea at this stage and requires experiment by a keen member who has a TPS on hand. I feel that the effort is worthwhile, Any takers ?



What do you think?