94 LT1 fuel pressure?
Thread Starter
Instructor
Joined: Sep 2003
Posts: 119
Likes: 0
From: Attleborough Norfolk
94 LT1 fuel pressure?
Hi all.
Have replaced all 3 O2 sensors ( as recommended by your good selves ) when 1 went wrong and all is well now..but while waiting for the new sensors I checked my fuel pressure and its 38 PSI but does go up briefly to 42 PSI when you blip the throttle, but returns ( at any RPM ) to 38 when throttle held steady( tried all RPM,s up to 4500 ) is this low? does it matter? The fuel pressure held for at least 20 mins..it did not bleed down quickly!
I do drive the Corvette hard but am not into racing.
Look forward to your replies
Cheers
John UK VetteNut :chevy
Have replaced all 3 O2 sensors ( as recommended by your good selves ) when 1 went wrong and all is well now..but while waiting for the new sensors I checked my fuel pressure and its 38 PSI but does go up briefly to 42 PSI when you blip the throttle, but returns ( at any RPM ) to 38 when throttle held steady( tried all RPM,s up to 4500 ) is this low? does it matter? The fuel pressure held for at least 20 mins..it did not bleed down quickly!
I do drive the Corvette hard but am not into racing.
Look forward to your replies
Cheers
John UK VetteNut :chevy
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: 94 LT1 fuel pressure? (JohnUKVetteNut)
It sounds like its fine. Check it this way, disconnect the vacuum line from the pressure regulator when the engine is running and idling, it should read around 43 PSI. Plus or minus 3 PSI. If thats is what you get then its fine.
Burning Brakes
Joined: Oct 2002
Posts: 983
Likes: 1
From: Bergen County NJ
Re: 94 LT1 fuel pressure? (tjwong)
:iagree:
Your numbers are good :yesnod: and are identical to mine.
I believe the pressure is supposed to be 41 psi (+/- a couple of psi tolerance). One side of the injector sees manifold vaccum, while the other side sees the fuel rail pressure. At idle, when you have good manifold vacuum, the fuel pressure will drop to maintain the 41 psi differential while at open throttle, as the manifold pressure goes up, the pressure regulator raises the fuel pressure to compensate.
Your numbers are good :yesnod: and are identical to mine.
I believe the pressure is supposed to be 41 psi (+/- a couple of psi tolerance). One side of the injector sees manifold vaccum, while the other side sees the fuel rail pressure. At idle, when you have good manifold vacuum, the fuel pressure will drop to maintain the 41 psi differential while at open throttle, as the manifold pressure goes up, the pressure regulator raises the fuel pressure to compensate.
