How To Test The Fuel Pump (2005-2006 2.2L Chevrolet Malibu)

Testing the fuel pump on the 2005-2006 2.2L Chevrolet Cobalt is a pretty simple affair.

This is due to the fact that you can easily connect a fuel pressure tester to the fuel system and check the pressure the fuel pump is producing.

In this tutorial I'll explain the fuel pump pressure test procedure in a step-by-step manner so that you can find out if the fuel pump is working or not.

NOTE: The Schrader valve is pictured above and this is where the fuel pressure tester is connected to to be able to get a fuel pump pressure reading.

Puedes encontrar este tutorial en Español aquí: Cómo Probar La Bomba De Combustible (2005-2006 2.2L Chevrolet Cobalt) (en: autotecnico-online.com).

Symptoms Of A Bad Fuel Pump

Defective fuel pumps usually cause one of two types of problems on your 2.2L Chevrolet Cobalt.

For the most part, the fuel pump will simply stop working and the engine will not get any fuel which causes it not to start.

In certain cases, the fuel pump will function enough to start the vehicle but the engine will not run optimally. This is due to the fact that the fuel pump is producing only enough fuel pressure to start the engine but not enough to drive the vehicle on the road.

These are the symptoms that you're going to see when the fuel pump has failed or is starting to fail:

  1. The engine cranks but does not start.
  2. The engine starts but stalls after a few seconds.
  3. The engine starts but as soon as you step on the accelerator pedal the engine stalls.
  4. Lack of power while driving the vehicle.
  5. Explosions can be heard coming from the intake manifold when you step on the accelerator while the engine is under load.
  6. The check engine light is on and lean air fuel mixture trouble codes are stored in the fuel injection computer's memory.

TEST 1: Testing The Fuel Pressure With A Fuel Pressure Test Gauge

Testing The Fuel Pressure With A Fuel Pressure Test Gauge. How To Test The Fuel Pump (2005-2006 2.2L Chevrolet Malibu)

As I mentioned at the beginning of the tutorial what makes testing the fuel pump a breeze, on your 2.2L Chevrolet Cobalt, is the fact that a fuel pressure test gauge can be easily connected to the fuel system.

This test port is called the Schrader valve. And the Schrader valve is located on the fuel injector rail.

NOTE: If you don't have a fuel pressure tester, you can run down to your local auto parts store and buy one there. If you want to save some bucks on this purchase take a look at my recommendations here: Where To Buy A Fuel Pressure Test Gauge.

FUEL PRESSURE SPECIFICATION: The fuel pressure specification for the 2005-2006 2.2L Chevrolet Cobalt is 50 to 60 PSI with the engine off or with the engine running.

These are the test steps:

  1. 1

    Remove the air cleaner assembly to access the Schrader valve which is located on the fuel injector rail.

  2. 2

    Connect your fuel pressure tester to the Schrader valve.

  3. 3

    Have your helper crank the engine while you observe the needle on the fuel pressure tester gauge.

  4. 4

    The fuel pressure tester should give you a reading between 50 to 60 PSI.

Let's examine your test results:

CASE 1: The fuel pressure is within the indicated specification. This is the correct test result and it lets you know that the fuel pump is working correctly in your 2.2L Chevrolet Cobalt.

CASE 2: You got 0 psi fuel pressure. This test result lets you know that the fuel pump is defective and is causing the engine to not start.

Before you replace a fuel pump make sure that the fuel pump relay and fuel pump fuse are supplying power to the fuel pump when the engine is being cranked. If battery power is available to the fuel pump, when cranking the engine, then you can confidently conclude that the fuel pump is defective and that it needs to be replaced.

CASE 3: The fuel pressure was below the indicated fuel pressure specification. This test result lets you know that even though the fuel pump is supplying some fuel it's not supplying enough to have the engine run optimally.

This is an indication that the fuel pump is failing and needs to be replaced.