TPS (throttle position sensor) specs/tolerance?

So... I finally got my new AutoXray ez-scan 4000 and hooked 'er up to the 99 XJ 4.0L to see whats up, and it shows the TPS at 14% when I am completely off of the gas and only goes to 87% at WOT. What would be considered out-of-spec for the TPS? I am having an intermittent problem where idle will drop to 300 RPM. It recovers right away, but may do it again shortly thereafter...or not for a few days. Thought maybe the TPS was to blame, but there are no dead spots (tested it with an analog meter).

Thanks in advance...

Mike W.

More likely it is the IAC and not the TPS.

If you have 5 volts in, 14% is 0.70 volts, and 87% is 4.35 volts, which does sound a bit low. It should be more like .83 volts and about 4.8 volts I think at least for the older models.

With the engine off, and power on, check Pin A to Pin B on the TPS wiring harness connector with the TPS disconnected, it should be reading 5 volts.