My moms 1996 Chevy Lumina will start and run for 1 seconds after that it stalls the mechanic thinks its starter his he right if not whats wrong i need an answer very quickly.?

No, if it runs for a second then dies, the problem is almost certainly *not* the starter. The starter only engages to *start* the engine. A faulty starter would prevent the engine from turning over at all, or it would crank slowly.

The problem is much more likely to be something preventing the engine from continuing to run *after* it starts:

* Fuel delivery: Clogged fuel filter, faulty fuel pump, problems with the fuel injectors. The car might be getting a brief burst of fuel then nothing.

* Ignition system: Faulty ignition coil, distributor cap/rotor (if it has one), ignition wires, or crankshaft position sensor (this is a common culprit on older cars). It might be briefly sparking then failing.

* Air intake: A severely clogged air filter could starve the engine of air. Less likely, but possible.

* Computer issues: A problem with the engine control module (ECM) or other sensors could cause a brief run then shutdown. This is less likely than the other options.

You need a proper diagnostic. A mechanic should be able to test these systems to pinpoint the problem. Just replacing parts randomly is a very expensive way to fix the car. Explain the symptom clearly ("runs for one second then dies") to the mechanic.