How To Test The Fuel Pump (3.4L V6 Buick, Oldsmobile)

Using Starting Fluid

I've been using the starting fluid test to diagnose a no-start problem for as long as I can remember.

It's the first test that lets me know in what direction to take my no-start diagnostic.

Although the starting fluid test will confirm that the engine is not starting due to lack of fuel, it's not the most accurate way to diagnose a bad fuel pump.

I still test the fuel pump pressure with a fuel pressure test gauge even after the starting fluid test has confirmed a lack of fuel condition.

IMPORTANT: To get the most accurate test result from this test you need to first make sure that all 6 spark plug wires are sparking. If you haven't already, test all 6 spark plug wires for spark with a dedicated spark tester.

OK, let's get testing:

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 one of the next steps.

2. 2

   Open the throttle manually, and spray starting fluid down the bore.
   
   When you have sprayed a good squirt of starting fluid, quickly reconnect the air duct to the throttle body (you don't have to tighten the hose clamp).
   
   Reconnecting the intake air duct is a very important safety precaution in case you get a back-fire thru' the intake manifold.

3. 3

   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 started and ran for a few seconds. This test result tells you that the engine notes our problem is due to a lack of fuel.

Usually this means that the fuel pump is bad but you still have to make sure with a fuel pressure test gauge.

For this test go to: Using A Fuel Pump Pressure Tester To Test The Fuel Pump.

CASE 2: The engine did not start, not even momentarily. This test result generally tells you that you are Vehicles no-start problem is not due to a lack of fuel. Still, I recommend doing a fuel pressure test to make sure

For this test go to: Using A Fuel Pump Pressure Tester To Test The Fuel Pump.

More 3.4L V6 Buick, Oldsmobile Tutorials

You can find a complete list of 3.4L V6 Buick (Oldsmobile) tutorials in this index:

• GM 3.4L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test Engine Compression Test (3.4L V6 Buick, Oldsmobile).
• How To Test A Blown Head Gasket (3.4L V6 Buick, Oldsmobile).
• What Does The CKP Sensor Do? (3.4L V6 Buick, Oldsmobile).
• How To Test The Throttle Position Sensor (3.4L V6 Buick, Oldsmobile).