My 94 Buick Lesabre limited starts cold and runs perfect for about 3min and then engine stops. Will not start until engine has cooled for 30min or more.
Getting fuel but no spark.
Replaced coil packs, ignition module, crank sensor, cam sensor. Cleaned and inspected mass airflow sensor, air filter, vacuum lines, plugs and wiring.
I'm thinking of replacing the throttle position sensor?
My best guess is a sensor is defective and sending a signal to the ECM to stop spark?
Nice car with many miles still to go.
Your help will be appreciated. Thanks

Welcome to GM Forum!

The crank sensor is the most common cause for this, but you say you've replaced it already. I don't think the TPS at fault; that would just cause a strange idle and drivability/shifting problems. What is your security light doing during all this?

Aloha SignofZeta,
The fuel pressure was checked by previous owner. runs perfectly for 3min at a time. Dies like I turned the key off and will not start for extended period of time. Security light is off while running and with key turned on.
Off to work now. Thanks for reply.

UPDATE: After reading about so many symptoms and possible solutions, I finally fixed it. The crank shaft sensor was bad (part of the magnetic pickup was c racked and falling off) and I replaced it. That'* when the car would run for a few minutes and then shut off. Replaced the cam sensor for the fun of it and the problem persisted.
I remembered someone out there in cyberspace mentioning the EGR valve and carbon build up causing it to stick open. I decided to pound it a few times with a 2x4 to see if it would pop back into place. Well, it did but kept sticking. I took the EGR off and sprayed it out with carb cleaner. turned it upside down so it could soak a few min. I then sprayed penetrating oil in and pushed the spring valve in and out rapidly. Let it soak and repeated. Sprayed it out with carb cleaner again and re-installed it. Car started right up and runs great now. Now I have to figure out why the cooling fan doesn't come on. LoL

Summary: replaced many sensors and only needed to replace crank sensor and clean EGR valve.
Check engine light is off now. WoooHoooo!!!
Now onto cooling fan problem.
Hope this will help someone. Sounds like many of the problems out there are EGR related.
Aloha and Mahalo!

Update: The radiator fan problem was not relay or temp sensor related as thought. The thermostat was stuck shut and not allowing water to circulate to the sensor. removed it because I live in a hot climate year round. Now the car runs great and the fans come on and keep it perfectly cool. Love it!! Car was free on craigs list!!!!