suburban

Maybe simple cleaning needed........ negative cable to battery and chassis------replace or disconnect and clean with wire brush Throttle body harness---check, replace or clean terminals and pins Grounds on both side of the engine blocks--clean and re-attach them

Next....check the starter relay in the fuse box by the battery

Lastly, Check Starter...if you are having this problem try and hold the key to the on position for 30 seconds and then try to start if it starts up its the Starter...its going bad