oil pressure gague?

Every now and then when I start my jeep the check gagues warning comes on and the engine oil pressure gague is at 0, it doesn't seem to run any different, and if I re-start the jeep it goes away and the pressure gague works again. You think this is just the sensor? Or an actual oil pressure problem?

Oil pumps typically going to work, or not, no in between.

I'd check for shorts in the sending unit

Is low oil pressure a symptom of the pump going bad (internal clearances getting too large)? When I start my 89 XJ 4.0L (208,000 miles) the pressure goes to 20psi and stays there pretty much all the time, every so often it will go up near 40psi, but never above. Idling at stop lights the oil pressure will dip down near 0psi giving it a little gas brings it back up to around 20psi, but the oil light has yet to light up.