In this tutorial, I'm going to explain how to test the fuel pump with a fuel pressure test gauge on the 1995-1999 3.1L V6 Chevy Lumina and Monte Carlo.
With your test results, you'll be able to easily find out if the fuel pump is bad or not.
I've also included the test instructions on how to test a lack of fuel with starting fluid.
Contents of this tutorial at a glance:
You can find this tutorial in Spanish here: Cómo Probar La Bomba De Combustible (1995-1999 3.1L V6 Chevrolet Lumina, Monte Carlo) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 3.1L Chevrolet Lumina: 1995, 1996, 1997, 1998, 1999.
- 3.1L Chevrolet Monte Carlo: 1995, 1996, 1997, 1998, 1999.
RELATED WIRING DIAGRAMS:
- Fuel Pump Wiring Diagram (1995 3.1L V6 Chevrolet Lumina, Monte Carlo).
- Fuel Pump Wiring Diagram (1996 3.1L V6 Chevrolet Lumina, Monte Carlo).
- Fuel Pump Wiring Diagram (1997 3.1L V6 Chevrolet Lumina, Monte Carlo).
- Fuel Pump Wiring Diagram (1998-1999 3.1L V6 Chevrolet Lumina, Monte Carlo).
Symptoms Of A Bad Fuel Pump
The fuel pump will usually fail in one of two ways:
- It will stop sending fuel to the fuel injectors and the engine won't start.
- It'll send just enough fuel to start the engine but the engine will run with serious drivability issues.
When the fuel pump sends barely enough fuel to start and keep the engine running, you'll see one or more of the following problems:
- Rough idle.
- Engine takes a long time to start (extended cranking time).
- Lack of power when accelerating the vehicle down the road.
- Engine backfires through the intake manifold when accelerating the vehicle down the road.
- Lean air fuel mixture trouble code: P0171: Fuel System Too Lean.
Where To Buy A Fuel Pressure Test Gauge
You can buy a fuel pressure test gauge just about anywhere and is one of the most important tools any serious DIY'er should have in his/her tool box.
The fuel pressure test gauge kit that'll connect to your Chevy Lumina or Monte Carlo's Schrader valve and that I recommend for its low price and durability is the: Actron CP7838 Professional Fuel Pressure Tester.
All of the following fuel pressure test gauge kits will help test your Chevy Lumina or Monte Carlo's fuel pump:
TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge
The most accurate way to test the fuel pump on your 3.1L Chevrolet Lumina (Monte Carlo) is to use a fuel pump pressure tester.
We'll connect the fuel pump pressure tester to the Schrader valve (see photo above) which is located on the fuel injector rail. To be a bit more specific, it's located between the alternator and the power steering pump reservoir.
NOTE: If you don't have a fuel pressure test gauge, you can run down to your local auto parts store and buy one there. You can also buy one online. Check out my recommendations here: Where To Buy A Fuel Pressure Test Gauge.
FUEL PRESSURE SPECIFICATION:
- 41-47 PSI Key On With Engine Off.
- With Key On Engine Running, fuel pressure should drop 3 to 10 PSI.
These are the test steps:
Place a shop towel around the Schrader valve.
Connect a fuel pressure gauge to the Schrader valve on the fuel rail.
When ready have your helper crank the engine while you observe the fuel pressure tester gauge.
The fuel pressure tester should register:
1995-1999 3.1L Chevrolet Lumina and Monte Carlo:
41-47 PSI Key On With Engine Off.
With Key On Engine Running: fuel pressure should drop 3 to 10 PSI.
Let's examine your test results:
CASE 1: The fuel pressure gauge registered 0 PSI. This test result lets you know that the fuel pump is not supplying fuel to the engine. Without fuel, the engine is not going to start.
If the engine in your Chevy Lumina (Monte Carlo) cranks but does not start, then you can conclude that the reason behind this is a defective fuel pump.
CASE 2: The fuel pump registered a pressure way below the specified range but not 0 PSI. This lets you know that the fuel pump is defective.
If the fuel pump is not supplying enough fuel to the engine, the engine may start and run but it'll run badly. In these cases you'll see one or more of the following:
- The engine will start and run but as soon as your put the transmission in Drive and accelerate, the engine stalls.
- The engine starts and runs, but you hear explosions coming from the intake manifold when you accelerate the engine.
- Lean air/fuel mixture trouble codes lighting up the check engine light.
CASE 3: The fuel pump registered a pressure within the specified range. This lets you know that the fuel pump is working within normal parameters. In other words, it's not defective.
If your 3.1L Chevrolet Lumina (Monte Carlo) is cranking but not starting, you can conclude that it's not due to a defective fuel pump.