About a week ago the fuel pump started to run continuously. It used to run for a short while and then stop without the engine running, but now it never stops. Fuel pressure is as usual, about 15 psi. There are no fuel leaks.

Any suggestions what may have changed and what is causing this?

 

Well that's different.

Usually it's the opposite.

 

Is this the factory in tank pump or an aftermarket pump

 

Relay sticking for the Airdog? I would start there.

 

X2...call air dog about a replacement relay.