97 gmc 5.7 p300

[97moneypit]

Fuel pressures ( new fuel filter )

ENGINE COLD

key on engine off
55-58 psi
Idle - 3000 rpm ( steady rev up )
45-48 psi
quick snaps of throttle
55-58 psi
engine off leak down
1 PSI drop every 30 secs

ENGINE HOT
key on engine off
55-58 psi
idle - 3000 rpm ( steady rev up )
45-48 psi
quick snaps of throttle
55-58 psi
engine off leak down
dropped from 48 psi to 34 psi in 1 min.

 

[Schurkey]

dropped from 48 psi to 34 psi in 1 min.

That can't be good.

 

[SUBURBAN5]

Got a leak somewhere

 

[97moneypit]

Any suggests what to check next ? Or what it could be.

 

[SUBURBAN5]

If it was me I'd check the fuel rail and injectors/ fp regulator. Now if anybody installed the wrong fuel pump then it could also cause fuel to drain out back into the tank making it look like your leaking fuel. Pretty slim on that one though. I only know that cause I did that mistake once...

 

[97moneypit]

If it was me I'd check the fuel rail and injectors/ fp regulator. Now if anybody installed the wrong fuel pump then it could also cause fuel to drain out back into the tank making it look like your leaking fuel. Pretty slim on that one though. I only know that cause I did that mistake once...

Im thinking injectors because I do also get p0303 most of the time with p0300.

Probably end up just doing them both and call it done.

Whats a good upgrade for injectors ?

 

[SUBURBAN5]

Im thinking injectors because I do also get p0303 most of the time with p0300.

Probably end up just doing them both and call it done.

Whats a good upgrade for injectors ?

Imo if you can ac delco mpfi. They use to list 2 part # not sure the difference. Either one seemed to work fine.