94 Buick Lesabre stalling

I have a 1994 Buick Lesabre that is stalling. Something is draining the battery, the battery has been replaced twice, it is good. A mechanic checked it and said he couldn't see a problem and put in a new battery. After it has been driven about 30 minutes/30miles it will die and the check engine light will come on. It will sometimes re-crank, sometimes has to be jumped off. It also pauses before it cranks. It seems to only behave this way with us, not the mechanic. Can someone help? :banghead:
Jennifer

i'd say it's fuel pump if you let them get low on gas this will cause it to go out..another thing is buying it at avanced or autozone they are guarnted as long as you own the car..

A number of LeSabre "flaky" problems are caused by bad battery cable terminals, so I would check that first. However, I'm not talking about just making sure they're tight, or maybe taking them off and cleaning the posts, then putting them back on, etc. I'm talking about cutting the plastic molding all the way off the cable ends to expose the metal connectors underneath. I'd be willing to bet you'll find oxidization crud under there, and probably even inside the cable strands where they're crimped to the post connector. If so, you'll have to do what's necessary to get rid of it, which may involve cutting the old connectors off and replacing them with new ones.

I would bet the iconmaster has something here. This happened to my daughters car about 4 years ago. After cutting the red plastic off and buying a post for two cables she hasn't had any more problems.