Fuel pressure

Tiny
FRODOE45
  • MEMBER
  • 2004 PONTIAC GRAND AM
  • 3.4L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 146,000 MILES
I checked my fuel pressure, key on engine off. Read (48 psi). Haynes manual said 52 to 59, key on engine off. I checked it also with the engine running, it read (40, 42 psi) fluctuating back and forth. I know the car has age. It doesn't seem to fall inspect or does it.
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Wednesday, November 20th, 2019 AT 8:46 AM

3 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
The pressure is a bit low. Have you ever replaced the fuel filter? A dirty filter can cause this to happen. Also, there is a sock at the bottom of the fuel pump assembly that functions as a filter that can also be clogging. And of course, the pump may be going bad.

________________________________________

Here are the directions for replacing the filter. The attached pics correlate with these directions. It's a good place to start especially if it hasn't been done for a long time.

First, here is a link that shows in general how one is replaced:

https://www.2carpros.com/articles/how-to-change-a-fuel-filter

Here are the directions specific to your vehicle:
________________________________________

2004 Pontiac Grand AM V6-3.4L VIN E
Procedures
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Filter Service and Repair Procedures
PROCEDURES
FUEL FILTER REPLACEMENT

REMOVAL PROCEDURE

IMPORTANT: There is no service interval for fuel filter replacement. Only replace the fuel filter if it is restricted. Inspect the fuel tank internally and clean the fuel tank if you find a restricted fuel filter.

Pic 1

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure.
2. Raise the vehicle. Refer to Vehicle Lifting.
3. Disconnect the fuel filter fitting using a back-up wrench.

pic 2

4. Disconnect the quick connect fitting from the fuel filter.
5. Remove the fuel filter.

INSTALLATION PROCEDURE

pic 3

1. Remove the protective caps from the new fuel filter.
2. Install the fuel filter (2) in the same position as the old fuel filter.
3. Connect the fuel filter quick connect fitting.

NOTE: Refer to Fastener Notice in Service Precautions.

4. Connect the fuel filter fitting (3) using a back-up wrench.

Tighten
Tighten the fuel filter fitting to 27 N.m (20 lb ft).

5. Lower the vehicle.
6. Connect the negative battery cable.
7. Inspect for fuel leaks using the following procedure:
7.1. Turn ON the ignition, with the engine OFF for 2 seconds.
7.2. Turn OFF the ignition for 10 seconds.
7.3. Turn ON the ignition, with the engine OFF.
7.4. Inspect for fuel leaks.

_____________________________________

Let me know if that helps. Also, I'm not sure where you are so I can't answer if it has an affect on inspection.

Take care,
Joe
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Wednesday, November 20th, 2019 AT 7:13 PM
Tiny
FRODOE45
  • MEMBER
Thank you. This is very helpful. I have replaced the fuel filter back awhile and pressure regulator. I am considering the pump. Because with the car running it only has in between 40-43 psi. Haynes said there will be a 5 psi decrease under load. Those low 40s' seem too low. I'll keep in touch. Thank you and God bless.
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Thursday, November 21st, 2019 AT 2:42 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

If you decide to replace the pump, the tank will need removed. Here are directions for tank removal and replacement. The attached pics correlate with the directions.

_______________________________

2004 Pontiac Grand AM V6-3.4L VIN E
Fuel Tank Replacement
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Tank Service and Repair Removal and Replacement Fuel Tank Replacement
FUEL TANK REPLACEMENT
FUEL TANK REPLACEMENT

REMOVAL PROCEDURE

pic 1

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure.
2. Drain the fuel tank. Refer to Fuel Tank Draining Procedure.
3. Raise the vehicle. Refer to Vehicle Lifting.
4. Disconnect the quick-connect fitting at the fuel filter.
5. Disconnect the fuel return pipe quick connect fitting.
6. Remove the rubber exhaust hangers. Allow the exhaust system to rest on the rear axle.
7. Remove the exhaust heat shield.
8. Loosen the fuel filler hose clamp at the fuel tank.
9. Disconnect the fuel filler hose from the fuel tank.
10. Disconnect the evaporative emission (EVAP) vapor pipe from the EVAP canister.

Pic 2

11. Disconnect the electrical harness from the multi-way rear body connector and fuel strap.
12. With the aid of an assistant, support the fuel tank (1).
13. Disconnect the fuel tank retaining straps.
14. Lower the fuel tank.
15. Remove the fuel sender assembly from the tank.

INSTALLATION PROCEDURE

pic 3

1. Install the fuel sender assembly to the fuel tank.
2. With the aid of an assistant, raise the fuel tank (1) to the vehicle.

NOTE: Refer to Fastener Notice in Service Precautions.

3. Install the fuel tank retaining straps.

Tighten
Tighten the strap bolts to 35 N.M (26 lb ft).

4. Connect the wiring harness into the multi-way rear body connector.
5. Connect the EVAP vapor pipe to the EVAP canister.
6. Connect the fuel filler hose to the fuel tank.

Tighten
Tighten the fuel filler hose clamp to 3 N.M (27 lb in).

7. Install the rubber exhaust hangers.
8. Install the exhaust heat shield.

Tighten
- Tighten the exhaust shield bolt to 2 N.M (18 lb in).
- Tighten the exhaust shield nuts to 1 N.M (9 lb in).

9. Connect the fuel return pipe and fuel filter quick-connect fittings.
10. Lower the vehicle.
11. Refill the fuel tank.
12. Install the fuel filler cap.
13. Connect the negative battery cable.
14. Inspect for fuel leaks.
14.1. Turn ON the ignition for 2 seconds.
14.2. Turn OFF the ignition for 10 seconds.
14.3. Turn ON the ignition.
14.4. Inspect for fuel leaks.

__________________________

I hope this helps. Let me know if the pump is the issue.

Joe
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Thursday, November 21st, 2019 AT 2:35 PM

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