How To Test The Fuel Pump (1995-1999 3.1L V6 Chevrolet Lumina, Monte Carlo)

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

Using starting fluid to see if the engine is not starting due to a lack of fuel is a very ancient test that automotive mechanics have been using since the age of carburetors.

The starting fluid test is not the most accurate way of testing a bad fuel pump, but can pinpoint a no-start problem to a lack of fuel.

This is probably the first test I perform when testing a 'cranks but does not start' problem.

IMPORTANT: For this test to give you an accurate test result, you need to make sure that all six cylinders are getting spark.

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 assistant 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 at all. This test result confirms that the no-start condition is NOT due to a lack of fuel from the fuel pump.

Remember, this test result is only valid if you have confirmed that all spark plug wires are sparking.

CASE 2: The engine started but died after a few seconds. This test result tells you that your 3.1L Chevy Lumina or Monte Carlo's no-start condition is being caused by a lack of fuel.