was performing normally running really well. No noises or alarms. Parked car overnight. Would turn over next morning but wouldn't start. Has fuel
,
good spark at plugs, but low cylinder pressure insufficient to start. How could this happen overnight when it ran great for 100 miles before parking?

Any thoughts? thanks Ian

 

Since you mentioned low cylinder pressure, does your engine crank over faster now than it did before this event happened? It could be bore wash from a battery that’s marginal and washed down your cylinder walls with fuel and collapsed the rings.