>>>27 amp cable about 10 meters long
It may well be the issue. I made up such a cable for my Bravo which was in theory rated to do the job but in reality it made the pump struggle. It was longer than I needed so I cut it in half which solved the problem.
My Bravo runs better with the car engine idling too.
>>Edit: I thought I put something in a post ages ago about this, here it is...
Just a small update. I said in the first post..... **I've already made up a heavy duty 5m extension cable (pump is a max 20a draw, I used 25a cable)**
Well I had made it up but not tried it. Turns out the guys who sold me the cable thought they were doing me a favour supplying 8m of cable. This was just too long re voltage drop despite being 25a cable. It was dropping under 9v at the pump making it stutter on the final bit of the air floor.
Cut the extension lead in half to still give a useful extra 4m and it now stays above 11v, and the pump runs far better.
Original thread... Bravo BTP12 Review