i fitted a 044 fuel pump a while ago and set fuel pressure to 3.5 bar vac pipe off as it should be.

since then i have re wired the fuel pump power and earth, i thought it best to re check the fuel pressure as the pump was working much better with the new wiring,
i couldnt get the pressure below 4.2 bar, so i assumed the reg was faulty ,changed the reg, and i still cant adjust the pressure below 4.2 bar, if i put pressure on the small hose to simulate boost the fuel pressure raises fine, but if i put a vaccum on it, the fuel pressure will not drop

i think the pump is now making to much pressure? i have 13.5 volts at the pump, any ideas?

 

damaged/blocked fuel return line ?

 

i suppose that is a possibility, does the return just dump straight in to the tank? so i could take the fuel cap off and try an air line down it?

 

this proves how bad my old wiring was the fuel pump sounds like a jet engine compared to what it was like before

 

yeah - the return line feeds into a small bore metal pipe sticking out of the tank

 

check the fuel lines by the n/s jacking point they are often crushed by trolley jack operators.
If your fuel pump sounds like a jet engine you have a serious fault some where

 

it was a damaged fuel line, i must have caught it on something in the lanes where i live

thanks for all your help guys