The fuel pump is easily tested with a fuel pressure test gauge. In this tutorial, I'll explain how to do it step-by-step.
With your test results, you'll easily and quickly determine if the fuel pump is behind your vehicle's engine no-start problem or an engine performance problem.
Contents of this tutorial:
- Symptoms Of A Bad Fuel Pump.
- Where To Buy A Fuel Pressure Test Gauge.
- Buick Rendezvous Fuel Pump Pressure Specification.
- Oldsmobile Alero Fuel Pump Pressure Specification.
- Oldsmobile Silhouette Fuel Pump Pressure Specification.
- Using A Fuel Pump Pressure Tester To Test The Fuel Pump.
- Using Starting Fluid.
- More 3.4L V6 Buick, Oldsmobile Tutorials.
APPLIES TO: This tutorial applies to the following vehicles:
- 3.4L V6 Buick Rendezvous: 2002, 2003, 2004, 2005.
- 3.4L V6 Oldsmobile Alero: 1999, 2000, 2001, 2002, 2003, 2004.
- 3.4L V6 Oldsmobile Silhouette: 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004.
Symptoms Of A Bad Fuel Pump
The fuel pump is a critical component of the engine management system; when it fails, the engine is going to resent it.
Generally, a faulty fuel pump causes one of two major problems:
- An engine no-start problem
- - or -
- An engine performance/driveability problem.
If the fuel pump is still supplying enough fuel to start the engine but not enough to keep it running optimally under load, you'll see one or more of the following symptoms:
- The engine takes longer than usual to start (extended cranking).
- The engine idle is very rough.
- The engine backfires thru' the intake manifold under load.
- The engine starts then dies.
Where To Buy A Fuel Pressure Test Gauge
A fuel pressure test gauge is a must-have tool to test the fuel pump on your 3.4L V6 Buick or Oldsmobile.
The following fuel pressure gauge kits will easily connect to the Schrader valve on the fuel injector rail of your vehicle's 3.4L engine.
Buick Rendezvous Fuel Pump Pressure Specification
| 2002-2005 3.4L V6 Buick Rendezvous | |
|---|---|
| KOEO | KOER |
| 52-59 PSI | Fuel pressure should drop 3 to 10 PSI |
Oldsmobile Alero Fuel Pump Pressure Specification
| 1999 3.4L V6 Oldsmobile Alero | |
|---|---|
| KOEO | KOER |
| 40-47 PSI | Fuel pressure should drop 3 to 10 PSI |
| 2000 3.4L V6 Oldsmobile Alero | |
|---|---|
| KOEO | KOER |
| 48-55 PSI | Fuel pressure should drop 3 to 10 PSI |
| 2001-2004 3.4L V6 Oldsmobile Alero | |
|---|---|
| KOEO | KOER |
| 52-59 PSI | Fuel pressure should drop 3 to 10 PSI |
Oldsmobile Silhouette Fuel Pump Pressure Specification
| 1996-1999 3.4L V6 Oldsmobile Silhouette | |
|---|---|
| KOEO | KOER |
| 40-47 PSI | Fuel pressure should drop 3 to 10 PSI |
| 2000-2004 3.4L V6 Oldsmobile Silhouette | |
|---|---|
| KOEO | KOER |
| 52-59 PSI | Fuel pressure should drop 3 to 10 PSI |
Using A Fuel Pump Pressure Tester To Test The Fuel Pump
In the photo above, you'll notice the location of the Schrader valve (next to the power steering pump reservoir).
To the Schrader valve, we'll connect the fuel pressure test gauge and check the fuel pump pressure.
NOTE: If you don't have a fuel pressure tester with the correct adapter, take a look at this section: Where To Buy A Fuel Pressure Test Gauge.
OK, these are the test steps:
- 1
Place a shop towel under the Schrader valve. The shop towel's job is to absorb any fuel that may leak when doing step 2.
- 2
Connect the fuel pressure gauge to the Schrader valve.
Most fuel pressure gauges can be connected to the Schrader valve without an adapter. If yours isn't one of them, connect the correct adapter to the Schrader valve and then connect the gauge to it. - 3
When ready, ask your helper to cycle the key ON and OFF but don't crank the engine while checking for fuel leaks.
If no fuel leaks, go to next step.
If fuel is leaking, resolve the leak before continuing to the next step . - 4
Crank the engine and observe the fuel pressure gauge.
- 5
The fuel pressure gauge should register the specified fuel pressure.
Let's take a look at your fuel pressure test results:
CASE 1: The fuel pressure test gauge registered 0 PSI. This test result confirms your vehicles no-start problem is due to a lack of fuel.
You can conclude that the fuel pump is not functioning and is the cause of the engine's no-start problem.
CASE 2: The fuel pressure gauge registered the indicated fuel pressure specification. This is the correct and expected test result and it confirms that the fuel pump is OK.
For more troubleshooting suggestions, take a look at the following engine no-start tutorial:
CASE 3: The fuel pressure gauge registered a fuel pressure way below the specification. This test result lets you know that the fuel pump is failing. Replace the fuel pump.
