Sometimes when I switch to another aircraft they load fine but without the engines running and I get the 'ctr-e' to start the engines. Does anyone have a solution to this and to why some are running and some are not. Thanks.

Well, try loading the default cessna, turning off everything, then saving it as default flight. That makes most of my planes go cold/dark at start. The others (like pmdg ngx) usually have their own system

Sometimes when I switch to another aircraft they load fine but without the engines running and I get the 'ctr-e' to start the engines. Does anyone have a solution to this and to why some are running and some are not. Thanks.

Try this, open FSX and launch your default flight. Then turn everything off. Save The next time you launch all engines will be off in all planes, except when in multiplayer. Josh