Fuel pressure
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Joined: Aug 2023
Posts: 4
Fuel pressure
My son's car
1997 camaro ss 6 speed All stock/original 100000 miles
Long cranking to start I have changed the fuel pressure regulator its a little better but not much
Tested fuel pressure today
at idle 32psi
At idle with vacuum line removed and plugged 40-41 psi
I'm assuming its probably time for a new fuel pump ??
Any help would be appreciated
Jamie
1997 camaro ss 6 speed All stock/original 100000 miles
Long cranking to start I have changed the fuel pressure regulator its a little better but not much
Tested fuel pressure today
at idle 32psi
At idle with vacuum line removed and plugged 40-41 psi
I'm assuming its probably time for a new fuel pump ??
Any help would be appreciated
Jamie
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Joined: Nov 1998
Posts: 71,087
From: Hell was full so they sent me to NJ
Re: Fuel pressure
Pressure is a bit low. GM spec for “no vacuum” pressure is 43.5 PSI, with a tolerance band of 41-47 PSI being acceptable. The 8 PSI drop when reconnecting the vacuum line is normal.
Have you changed the fuel filter?
When you turn the key to “RUN” and the pump primes for 2-seconds, what is the highest pressure? How fast does the pressure drop off after the pump shuts off. Rapid pressure drop can point to failure of the check valve in the pump, leaking FPR (you eliminated that), leaking line including the flex hose in the tank, leaking fuel injector(s). Rapid loss of pressure could indicate one of those problems, and increase cranking time.
Have you changed the fuel filter?
When you turn the key to “RUN” and the pump primes for 2-seconds, what is the highest pressure? How fast does the pressure drop off after the pump shuts off. Rapid pressure drop can point to failure of the check valve in the pump, leaking FPR (you eliminated that), leaking line including the flex hose in the tank, leaking fuel injector(s). Rapid loss of pressure could indicate one of those problems, and increase cranking time.
Thread Starter
Registered User
Joined: Aug 2023
Posts: 4
Re: Fuel pressure
Pressure is a bit low. GM spec for “no vacuum” pressure is 43.5 PSI, with a tolerance band of 41-47 PSI being acceptable. The 8 PSI drop when reconnecting the vacuum line is normal.
Have you changed the fuel filter?
When you turn the key to “RUN” and the pump primes for 2-seconds, what is the highest pressure? How fast does the pressure drop off after the pump shuts off. Rapid pressure drop can point to failure of the check valve in the pump, leaking FPR (you eliminated that), leaking line including the flex hose in the tank, leaking fuel injector(s). Rapid loss of pressure could indicate one of those problems, and increase cranking time.
Have you changed the fuel filter?
When you turn the key to “RUN” and the pump primes for 2-seconds, what is the highest pressure? How fast does the pressure drop off after the pump shuts off. Rapid pressure drop can point to failure of the check valve in the pump, leaking FPR (you eliminated that), leaking line including the flex hose in the tank, leaking fuel injector(s). Rapid loss of pressure could indicate one of those problems, and increase cranking time.
thanks for the quick response
yes it also has a new filter
I have not checked bleed down but I will this evening
Thanks for the info
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