It sounds like there are some mods at cross-purposes here. Something deleted the engine sound file during an installation process, so you'll probably have to load that sound again into the Sounds folder to get the engine sounds back. Check the files that came with your F-14.
As for weapons -- weapons are classified differently in the add-on Weapons Pack from the way they are in the stock game. This is causing loadout problems in a lot of third-party aircraft. You're going to have to do what's know as a "data.ini edit" for your F-14 in order to get a full loadout with the Weapons Pack.
Inside your F-14 folder you'll see a file called 'F-14_data'. If you open that up and scroll down to the [Weapons] section, you'll see entries called 'AttachmentTypes'. These are hardpoints, and there will be a classification entered next to each one: WP, NATO... something along these lines. Sometimes you'll see multiple entries next to a single 'AttachmentType.'
Whatever the case may be, some of the entries at these 'AttachmentTypes' make the F-14 "blind" to a lot of the weapons in the new Weapons Pack, so you're going to have to do some editing. If you open up Bunyap's Weapons Pack manual, you'll see a table entitled 'Nation Name and Attachment Type Table.' This tells you what entries need to be made next to the 'AttachmentTypes' to allow your plane to "read" the new Weapons Pack files.
I see an entry for 'United States Navy' -- USN. Assuming that the loadout scheme for the F-14 is USN, that is the *only* entry you should have at the F-14's ATs. Anything *other* than USN, such as WP or NATO, will have to be deleted to get the F-14 to read the Weapons Pack USN weapons. Multiple entries are no longer supported when using the Weapons Pack.
You might have to go through this process with every third-party plane in your stable, unfortunately