run then cut off and 30 to 45 minutes later will start right up
Sounds like the Ignition Control Module. Take it out and an auto parts store can test this since it is kinda spendy. The engine heat will affect the ICM when they start to go bad.
you'll have to check for spark and fuel , pull a plug wire and insert a short jumper wire in the plug wire boot the spark should arc to a ground , there's a fuel pressure test valve that looks like a tire valve , you can turn the key on/engine off and see if there's fuel pressure by pushing the little pintle , the fuel pump will prime the system for start ,go easy because the fuel will spray out so have a rag ready . This is the caveman method and is not recommended so don't set anything on fire , the motor should be cool . I figure you don't have a fuel pressure gauge but it's a place to start . Let us know how you make out .
O.K. thats not my user name and don't know what happened there but let us know how you do .
Looking for a Used Century in your area?
CarGurus has 777 nationwide Century listings starting at $1,600.
Search Buick Century Questions
Buick Century Experts
Related Models For Sale