Could do with some help please. My car was running fine until it went into the garage to get a new fuel pump and tank, Now when it gets to about 4000 rpm it backs off poping and missfiring ( might be detonation?) here's a quick spec
Stage 3 head
Hybrid T3
Forged pistons
Uprated intercooler

Its running about 15 psi, Any advice would be mint thanks

 

It would certainly seem to be down to fuel pressure, maybe neeeds setting up again if that has changed, was the old pump no good as say running fine but new pump fitted ?
tabetha

 

Yeah was running fine till new pump fitted, Maybe old pump was uprated? I know garage just put standard one on. But they said car wouldn't start till they replaced pump