Why does my 1992 mercury sable run good then wont start intermittenly why does car run good for weeks then wont start ?

Try a lubricant.

Mercury Sable key ? Mile High Locksmith ™

www.denver-locksmith.net/2013/12/mercury-sable-key-replacement/
Dec 23, 2013 - Mercury Sable keys have changed over the years. ... 1991, 1992, 1993, 1994, or 1995, then your car requires two keys. ... If your Mercury Sable was made in the year 1997, then some of the cars will have a transponder key, and some won't. ...Insert the new key into your ignition switch and turn it to the on .

Fuel pump .

Hi
Your symptom shows sign towards Starter motor is sticking or tooth in the flywheel is broken.

fuel pump? cehck pressure with gauge. should be 40 psi

try spraying starting fluid in the air intake or throttle bosy and se if it starts then. If yes, may be fuel pump in gas tank.

you got a miss in the ign. system do a full tune-up, wires, plugs and filters

while you state the battery is "strong" what kind of voltage are you getting to the starter solenoid

hi check fuel pressure if it dies out after warming up then you have a faulty fuel pump good luck

I can not tell you what is shorting, however if you have a car manual you will see circuit breakers in the fuse panel. The quick resetting sounds like circuit breakers working. You may be able to feel the clicking if you put your finger on the breaker. Then remove it and see what does not work. You may be able to isolate the problem enough to trace it. Good Luck

I have a 1992 Mercury Sable.  Let me guess.  You are running into the infamous "car dies for no reason".  You wait for a few minutes and the car starts right back up and dies a few miles later?  Well, in any case.  There really is no Fuel Pump Relay, not by itself anyway.  If you open the hood of the car and right on top of where the radiator is, there is a plastic splash guard.  Take that off and there should be a 4" by 4" or so black box with about 40 wires going to it sitting right on top of the radiator.  This has your fuel pump relay, cooling fan relay and about 20 different things in it.  You need to replace that box.  Go to a junk yard and get one for 10 bucks or so.  There is a bolt holding the wire harness on.  Take that out and the wire harness will come right out.  Make sure you D/C your battery and wait at least 10 minutes.  Just to make sure your airbags dont go off by accident.  Hope this help.  Please Rate!