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

TEST 2: Using Starting Fluid To Diagnose A No-Start Condition

If you don't have a fuel pressure test gauge and you want to find out if the engine's no-start problem is being caused by a lack of fuel, then I recommend doing a starting fluid test.

This test involves spraying starting fluid into the throttle body and cranking the engine. If the engine is not starting due to a lack of fuel then it'll start and run for a few seconds (till the starting fluid you just sprayed is consumed).

Now let me tell you that a starting fluid test is not a very precise way of checking the fuel pump. But it does help in pinpointing the no-start problem to a lack of fuel (if the fuel pump isn't working).

IMPORTANT: For the starting fluid test to give you an accurate test result you first have to make sure that all 4 cylinders are getting spark. So if you haven't already checked for spark yet, you should do so before doing the starting fluid test.

These are the test steps:

1. 1

   Remove the intake air duct from the throttle body. You don't have to completely remove it, since you'll have to reconnect it in step 2.

2. 2

   Spray starting fluid down the bore of the throttle body.
   
   After spraying a good squirt of starting fluid, quickly reconnect the air duct to the throttle body (you don't have to tighten the hose clamp)

3. 3

   Have your helper crank the engine once the intake air duct is back on the throttle body.

4. 4

   You'll get one of two results with this test:
   
   1.) The engine will start momentarily and after a few seconds will die.
   
   2.) The engine will only crank but not start at all.

OK, let's find out what your results mean:

CASE 1: The engine did not start, not even momentarily. This test result tells you that a lack of fuel from the fuel pump IS NOT causing the engine to not start in your 2.2L Chevrolet Cobalt.

I want to point out that this conclusion is true only if all 4 spark plug wires are sparking.

CASE 2: The engine started but died after a few seconds. This test result tells you that the engine, of your Chevy Cobalt, is not starting because it's not getting fuel.

I want to point out that this conclusion is true only if all 4 spark plug wires are sparking.

More GM 2.2L Test Tutorials

If this tutorial was helpful, be sure and take a look at all of the 2.2L Chevrolet Cobalt test tutorials in this index: GM 2.2L Index Of Articles.

Here's a sample of the tutorials you'll find there:

• Electronic Throttle Body Tests (2005-2006 2.2L Chevrolet Cobalt).
• TAC System Wiring Diagram (2005-2009 2.2L Chevrolet Cobalt And Pontiac G5).
• APP Sensor Tests (2005-2010 2.2L Chevrolet Cobalt And Pontiac G6).
• How To Test The MAP Sensor (2005-2006 2.2L Chevrolet Cobalt).