but problem remains, although not as easy to reproduce on the ground as before.
What problem remains? The engine quitting on you?
Have you looked in the log book to see if the engine driven fuel pump was replaced overhauled when the engine was overhauled. When was the electric pump overhauled? It will all be in the engine log book.
Why do you continue to fly an aircraft with a known problem?
I am not trying to be awkward, but this was my very point earlier, if you ask for trouble you bet you will find it.
FWIW I would no more test an aircraft's pressurisation at night over hostile terrain than I would continue to fly an aircraft with a known problem that could result in the engine quitting. The reason you have an electric pump is so, when the mechanical pump quits, you have a backup. If you know or suspect the mechanical pump could be faulty you have just defeated the intention of the designer in specifying a backup electric pump.
It flies
Please save us. I dont think you will get anything either new or which could not be found from doing a little research on Google.
