i've been chasing this problem for a month now, and just noticed the main fuel pump is noisy and warm. did the fuel flow test at the fuel rack and shorted the 2 pins at the fuel relay and only got about 1 liter of fuel after 10 seconds. i'm thinking that at 35 to 45 psi you get a lot more fuel then that. the original problem was a rough idle and it would cut out. got a new tank sending unit and pump. still the same, but adjusted the idle, and runs ok past idle, but when warm, push the peddle and nothing, but after a bit rev's up. pinched all the vaccum lines one at a time, idle doesn't change. when the pump is noisy, rev's die down. do these pumps get airlocked or vapour locked and how do get rid of it?

any thought's, or go for the main pump (expensive)