Engine shudder

STRYKERPPP

MEMBER
2008 PONTIAC G5
2.4L
4 CYL
2WD
AUTOMATIC
97,000 MILES

While traveling down highway car started to lose power. When trying to apply more gas it had no response like it wasn't getting fuel. Pulled off road and car sputtered and shut off. No warning lights appeared. After a minute or so I tried restarting car, car started and seemed to be idling okay. I put in gear and proceeded to drive. About a 1/2 mile later I exited highway and pulled into a gas station. I turned off engine and fueled car up. Turned engine back on and as I was leaving gas station car sputtered again and engine shut off. When I tried restarting, the engine tried to turn over and stopped and I heard a humming sound for a few seconds then afterwards the humming stopped. But each time I tried restarting, the engine would try to turn over then stop and the humming started and stopped like something was trying to activate. The man who towed the vehicle said he had that problem once and said it was the fuel pump not activating or clogged after I told him about the humming sound. It made sense to me cause as I said above I mentioned that car seemed to not be getting fuel. Can you verify?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,752 POSTS

Welcome to 2CarPros.

I will be happy to help. Honestly, the only way to confirm it is the fuel pump is to check fuel pump pressure. To replace the pump is a big job and you want to be sure before you replace it that the pump is the problem. There are other things that can cause this too, but since you were hearing the noise, lets start with the pump.

To determine if the pump is bad, you need to check fuel pressure. Here is a link that explains how it is done. You will need a fuel pressure gauge, but if you don't own one most parts stores will lend or rent one to you.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Also, here is a link that explains the most common causes of a crank / no start condition. Take a look through it. It explains how to check for problems.

https://www.2carpros.com/articles/car-cranks-but-wont-start

Here is the manufacturer';s specifications for fuel pressure:

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2008 Pontiac G5 L4-2.4L
Pressure, Vacuum and Temperature

Fuel Pressure (Key ON, Engine OFF) .................... 345-414 kPa (50-60 psi)

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If you determine the pump is bad, here are the directions for replacing it. The fuel tank will need removed to gain access. I will include those directions second. All attached pics correlate with the directions.

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FUEL PUMP MODULE REPLACEMENT
Fuel Pump Module Replacement

Special Tools

* J39765 Fuel Sender Lock Nut Wrench
* J45722 Fuel Sender Lock Ring Wrench

Removal Procedure

Caution: Refer to Gasoline/Gasoline Vapors Caution.

Caution: In order to reduce the risk of fire and personal injury that may result from a fuel leak, always replace the fuel sender gasket when reinstalling the fuel sender assembly.

pic 1

1. Remove the fuel tank.
2. Disconnect the fuel tank harness electrical connector from the fuel pump module.
3. Remove the fuel tank harness from the retaining features on the fuel tank and remove the harness.

pic 2

4. Remove the fuel feed and return lines from the retaining features (1) on the fuel tank.

pic 3

Notice: Avoid damaging the lock ring. Use only J-45722 to prevent damage to the lock ring.

Notice: Do Not handle the fuel sender assembly by the fuel pipes. The amount of leverage generated by handling the fuel pipes could damage the joints.

Important: Do NOT use impact tools. Significant force will be required to release the lock ring. The use of a hammer and screwdriver is not recommended. Secure the fuel tank in order to prevent fuel tank rotation.

5. Use the J45722 (1) and a long breaker-bar in order to unlock the fuel sender lock ring. Turn the fuel sender lock ring in a counter-clockwise direction.

pic 4

Important:
* Some lock rings were manufactured with "DO NOT REUSE" stamped into them. These lock rings may be reused if they are not damaged or warped.

* Inspect the lock ring for damage due to improper removal or installation procedures. If damage is found, install a NEW lock ring.

* Check the lock ring for flatness.

Place the lock ring on a flat surface. Measure the clearance between the lock ring and the flat surface using a feeler gage at 7 points.
6. If the warpage is less than 0.41 mm (0.016 in), the lock ring does not require replacement.
7. If the warpage is greater than 0.41 mm (0.016 in) the lock ring must be replaced.

pic 5

8. Slowly lift the fuel pump module (2) up until the fuel level sensor float arm is just visible. Ensure that the fuel level sensor harness connector clears the tank opening.

Important: When removing the fuel pump module from the fuel tank, be aware that the pump module reservoir bowl is full of fuel. The reservoir must be tipped slightly during removal to avoid bending the fuel level sensor float arm.

9. Tilt the fuel pump module (2) toward the front of the fuel tank to enable the level sensor float arm to clear the tank opening. Remove the pump module (2) from the tank.
10. Remove the fuel pump module lock ring (1).
11. Discard the fuel in the pump module reservoir bowl into an approved fuel container.

Important: Do NOT reuse the old fuel pump module-to-fuel tank seal.

12. Remove and discard the fuel pump module seal (3).

Installation Procedure

pic 6

1. Position a NEW fuel pump module seal (3) onto the fuel tank.
2. Install the fuel pump module lock ring (1) over the module feed and return lines and into position on top of the module.

Important: The reservoir must be tipped slightly during installation to avoid bending the fuel level sensor float arm.

3. Tilt the fuel pump module (2) toward the front of the fuel tank to enable the level sensor float arm to clear the tank opening. Install the fuel pump module (2) to the fuel tank.
4. Slowly lower the fuel pump module (2) into the tank. Ensure that the fuel lines align with the cut outs in the tank.

pic 7

Important:
* Ensure that the fuel pump module lock ring is fully seated within the fuel tank retaining tab slots.

* Always replace the fuel sender seal when installing the fuel sender assembly. Replace the lock ring if necessary. Do not apply any type of lubrication in the seal groove. Ensure that the lock ring is installed with the correct side facing upward. A correctly installed lick ring will only turn in a clockwise direction.

Use the J45722 (1) in order to install the fuel sender lock ring. Turn the fuel sender lock ring in a clockwise direction.

pic 8

5. Secure the fuel feed and return lines to the retaining features (1) on the fuel tank.

pic 9

6. Position the fuel tank harness and connect the fuel tank harness electrical connector to the fuel pump module.
7. Install the fuel tank harness to the retaining features on the fuel tank.
8. Install the fuel tank.

______________________________

Here are the directions for removal and replacement of the fuel tank.

______________________________

2008 Pontiac G5 L4-2.4L
Fuel Tank Replacement

Removal Procedure

Caution: Refer to Gasoline/Gasoline Vapors Caution.

pic 10

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief (With CH 48027) Fuel Pressure Relief (Without CH 48027).
2. Drain the fuel tank. Refer to Fuel Tank Draining.
3. Raise and support the vehicle. Refer to Vehicle Lifting.
4. Disconnect the fuel pump module fuel feed (2) and return (1) line quick connect fittings from the fuel filter.
5. Cap or plug the fuel filter feed and return line fittings in order to prevent fuel loss and/or system contamination.
6. Cap or plug the fuel pump module feed and return lines in order to prevent fuel loss and/or system contamination.

pic 11

7. Disconnect the fuel tank evaporative emission (EVAP) line quick connect fittings (2, 3) from the EVAP canister.
8. Cap or plug the EVAP lines and canister fittings in order to prevent system contamination.

pic 12

9. Disconnect the fuel tank vent line quick connect fitting (2) from the fill pipe recirculation line.
10. Loosen the fuel fill hose clamp (3) at the fuel tank.
11. Remove the fuel fill hose from the fuel tank.
12. Cap or plug the fuel tank opening and vent line in order to prevent fuel loss and/or system contamination.

pic 13

13. Disconnect the fuel tank harness electrical connectors (1 and 3) from the body harness pass thru connector (2).

pic 14

14. Disconnect the fuel tank harness electrical connector (1) from the fuel tank pressure sensor.
15. Disconnect the fuel tank harness electrical connector (2) from the EVAP canister vent solenoid valve.
16. Remove the harness retainers from the underbody.

pic 15

17. Release the exhaust muffler assembly insulators from the underbody hangers and slowly lower the exhaust, allowing it to rest on the rear axle beam.

pic 16

18. Use a suitable jack to support the fuel tank during the fuel tank strap and tank removal.
19. Remove the left (L) fuel tank strap bolts and strap.
20. Remove the right (R) fuel tank strap bolts and strap.
21. In order to clear the exhaust muffler assembly, slowly lower the right side of the fuel tank. Use care when feeding the fuel, EVAP lines, and electrical harness around rear axle.
22. Once the fuel tank is clear of the right frame rail, remove the fuel tank down and toward the right side of the vehicle.
23. If the fuel tank is be replaced, remove the fuel pump module.

Installation Procedure

pic 17t

1. If the fuel tank was replaced, install the fuel pump module.
2. Use a suitable jack to support the fuel tank during the fuel tank and strap installation.
3. Install the left side of the fuel tank over the exhaust muffler assembly.
4. Raise the right side of the fuel tank into position inboard of the right frame rail. Use care when feeding the fuel, EVAP lines, and electrical harness over the rear axle.
5. Install the right (R) fuel tank strap and bolts.
6. Install the left (L) fuel tank strap and bolts.

Notice: Refer to Fastener Notice.

7. Tighten the fuel tank strap bolts.

Tighten the bolts to 25 N.m (18 lb ft).

pic 18

8. Raise the exhaust muffler assembly into position and install the insulators to the underbody hanger.

pic 19

9. Connect the fuel tank harness electrical connector (1) to the fuel tank pressure sensor.
10. Connect the fuel tank harness electrical connector (2) to the EVAP canister vent solenoid valve.
11. Install the harness retainers to the underbody.

pic 20

12. Connect the fuel tank harness electrical connectors (1 and 3) to the body harness pass thru connector (2).

pic 21

13. Remove the cap or plug from the fuel tank and vent line openings.
14. Connect the fuel fill hose to the fuel tank. Align the "D" notch on the fill hose (1) with the "D" notch on the fuel tank (1).

Notice: Refer to Component Fastener Tightening Notice.

15. Tighten the fuel fill hose clamp (3).

Tighten the clamp to 4.5 N.m (40 lb in).

16. Connect the fuel tank vent line quick connect fitting (2) to the fill pipe recirculation line.

pic 22

17. Remove the caps or plugs from the EVAP lines.
18. Connect the fuel tank EVAP line quick connect fittings (2, 3) to the EVAP canister.

pic 23

19. Remove the caps or plugs from the fuel pump module fuel feed and return lines.
20. Remove the caps or plugs from the fuel filter feed and return line fittings.
21. Connect the fuel pump module fuel feed (2) and return (1) line quick connect fittings to the fuel filter.
22. Lower the vehicle.
23. Refill the fuel tank.
24. Connect the negative battery cable.
25. Inspect for fuel leaks using the following procedure:

1. Turn ON the ignition, with the engine OFF for 2 seconds.
2. Turn OFF the ignition for 10 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Inspect for fuel leaks.

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I hope this helps. Let me know if you have other questions.

Take care,
Joe

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