How come they had to keep push starting Jimmie Johnsons car at the Coca Cola 600?

May be...

Moisture in the electrical parts. Kyle Busch was having a problem with his oil gauge because of the moisture.

I had a Chevrolet like that once. Never again!

I'm sure it was due to all the rain and moisture. Kyle Busch also had a problem that they figured was due to the rain. Kyle said he was smelling electrical smoke and everyone came to the conclusion that some water probably caused that as well.

The nascar engines are started by a starter pannel and all that is electric and when the rain came poof the starter went

I agree with your first answer. The moisture from the rain played havoc on Jimmie's car.

yeah the constant rain and car coverings messed up his car. as we all know, the nascar cars aren't made for the rain. so his car fell victim to mother nature. what a shame though, his paint scheme for memorial day was awesome.

I think they said his starter messed its diaper because of the rain. No problems in and out of the pits, so the tranny was fine.

looked like his started shorted out or something inside the car got wet or maybe the battery wasnt holding a charge

It's a fraqkkin' Chevy, what do you expect? Maybe next year after Chevy is out of racing all the cars will run.

The Moisture of the Rain caused problems.
As they said "These cars weren't made to race in the rain" I think Mike Joy stated that.

did they ever say what was wrong with it?

I would say he lost 1st gear... none of the other Hendrick cars had a problem.... getting started anyway...make music files