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
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
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
Have your assistant crank the engine once the intake air duct is back on the throttle body.
- 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.
If this info saved the day, buy me a beer!
