1996 Chevy Lumina No Start

I have a 1996 Lumina with a 3.1 liter engine. It stopped while driving ( it did not sputter) leaving me to believe it was an electrical problem and not a fuel or mechanical problem. Its a no start now. Timing chain is visibly ok. I checked the rocker arms thru the valve covers. They dont move when turning it over. The oil did smell slightly of gasoline.The shop says that cylinder pressure was low but they didnt give me a reading. I think that maybe they tried to start it too much and may have washed the cylinder walls down with an oil/gas mixture. There is spark and it did try to start after it died but never again with repeated tries. Spark plugs are ok/clean,still no start. There was no sound of low oil pressure (the oil pressure light was not on) from the engine before it stopped.