1999 Old 88 The engine cuts off as soon as it gets to operating temp (198')

what are the fixits you've had done?

Tune-up (Plugs, air-filter etc) New catalytic converter. Reading other postings here could the problem be distributor/coil?

what motor is it?

3.8 liter V-6 multi-pt Fuel inj

crank or cam sensor are known to cause shutdowns and the associated wiring/plugs that go to them. does sound like you lose all spark momentarily causing shutdown.

Exactly "losing all spark momentarily".
What's the fix for 'Crank or cam sensor'?
Thanks

did you check for codes?

Mechanic ran the diagnosis - no problem there.
One person who used to work at the OLDS plant suggested that this car has a 'over-heating' cut-off switch.
Apparently it activates when the engine gets hot to protect the engine.
Anyone know:-
1 - Is there is such a switch on this car.
2 - How to test it.
3 - How to repair/replace it?

never heard of it. most people just replace crank and or cam sensor but they can be tested. but thats usually a no start issue an intermittent fault is not easily tested for.

New info!
- I disconnected the engine fan so it heats up quicker.
- The engine idles regardless of how hot it gets.
BUT, then you can only drive half a block and it quits.
- Then, it takes longer to cool down before it will restart.
- So, somehow the problem is the engine heating up AND driving. . .
-

when it quits you say it starts immediately. this is not sufficient time or anything to cool off? so heat may not be the absolute cause?

As I mentioned in my original post, if it cuts off while I'm driving at speed, I shift into neutral (without stopping) so coasting for a minute or so, cools it enough to restart.
Also, if I HAVE TO get somewhere and can avoid low sped, I coast when I can, and turn off the ignition if I get a red light. So, as long as I don't have to idle or drive slow I can keep going for quite a while. That's why I really think it's heat related. . . .

you could take the ignition module into auto chain parts store and they can test it. they run a test like 10 times to heat it up to check for heat failure. or do like most amateurs and just start replacing likely parts like crank sensor/cam sensor.

Thanks for the response. It's in the shop today getting the crank sensor replaced. So, I'll get the Ignition Module heat-tested too.
As I mentioned above, by keeping the temp guage below 195' the car will keep running, but, as soon as I hit traffic or drive at low speed for any length of time, as soon as the temp gets over 200' it stops.
BUT, if I idle in park the temp goes way up, with no problem, but as soon as I drive, within a minute, it stops.
So it's not just engine temperature. It must be something electrical which is activated in drive. . . . .