Milky

My car takes about 5 seconds of holding the ignition over to start the car. I checked the pressure the pump is putting out and its only about 5psi and eventually fades to 0psi in a matter of seconds and when I start the car my fuel pressure will MAX out at about 30psi which is not enough for my application I need ~40psi... Does this point to the fuel pump or the regulator? Both are new (Mallory fuel pressure regulator and BBK 255lph fuel pump)

Thanks for the help guys

cammedlx

if the fuel pump was bad the car would not start at all kinda sounds like the regulator to me

Milky

Could a bad ground to the fuel pump just make it weak enough to put out only that 30psi? The kit came with a half *** but connector that I suspect came loose... could that cause my problem? Thanks stangpower

cammedlx

well if you had a bad ground then it would be a hit and miss kinda of thing you know sometimes the fuel pump works and then sometimes it would'nt but you could check it if you would like too but i would just look at the regulator maybe even at a partialy clogged fuel filter and your welcome

roundman

bigger pumps like that draw more amps too, so make sure the power wires are large enough to carry the current load.
you can try using a battery hooked up with larger wires right to the fuel pump wiring in the trunk to see if this brings the pressure up, if it does, then you need to rewire the harness with larger wiring.
did you set the fuel pressure regulator correctly?? did you reconnect the vacuum hose to it??? this could definitely be the source of your problem too! on mine, it said to have the key on but engine off and set the screw so that the fuel pressure was about 48-50 with the engine off. then with the vacuum hose on and the engine running, the fuel pressure will be about 44 psi at WOT.

Milky

MY BBK 255lph pump I was told is too big.. I had it given to me and my stock pump wasn't putting out enough so I installed the 255 but since its going to be replaced, should I size down to 190lph or maybe 155lph?

vfast

he could have a vacuum leak making the pussure go down