That's my main problem at present. After the car sits for an hour or so, hot, it won't start. When I operate the hand pump I can look at the clear filter and see little bubbles of air coming back up from the pump body. There's a large brass bolt head in the pump body just below the fuel intake line. It must be a 26-28 mm bolt. I was thinking about taking that loose and seeing what was in there. Is this a good idea?