How To Test The Fuel Pump (2001-2005- 2.4L Chrysler Voyager And Dodge Caravan)

I think that you're going to be very surprised at how easy it is to find out if the fuel pump is good or bad on your minivan.

In this tutorial, I'll break down the fuel pump pressure test into easy steps. With you test results, you'll quickly find out if the fuel pump is good or bad.

You can find this tutorial in Spanish here: Cómo Probar La Bomba De Combustible (2001-2005- 2.4L Chrysler Voyager y Dodge Caravan) (at: autotecnico-online.com).

APPLIES TO: This tutorial applies to the following vehicles:

• 2.4L Chrysler Voyager: 2001, 2002, 2003.
• 2.4L Dodge Caravan: 2001, 2002, 2003, 2004, 2005.

CAUTION: Gasoline and starting fluid are extremely flammable. Be careful and take all necessary safety precautions. Make sure to perform all tests with a cooled down engine, work in a well-ventilated area, and stay away from open flames or sparks.

Symptoms Of A Bad Fuel Pump

From what I've seen over the years I've wrenched on cars, a fuel pump generally fails in one of two ways:

1. Complete failure: This is the kind you see most often, and it results in an engine no-start problem.
2. Slow failure: Here, the engine starts but runs poorly, especially when it's under load.

To be a bit more specific, here are some of the symptoms you'll see from a complete fuel pump failure:

• The engine cranks but doesn't start.
• No fuel pressure is detected.
• No noise from the fuel pump.

These are some of the symptoms of a slow fuel pump failure:

• Lack of power when accelerating the engine under load.
• Unexplained loss of power.
• Bad gas mileage.
• The engine suddenly stalls.

Whether your mini-van's fuel pump has totally failed or is just beginning to, a fuel pressure test will pinpoint the issue. Plus, this easy and straightforward test will fast-track your troubleshooting efforts, so you'll waste less time and feel less frustrated as you find and replace the faulty part.

Where to Buy a Fuel Pressure Gauge

You're going to need a fuel pressure test gauge to test the fuel pump's pressure on your minivan. The following links are my recommendations and I think they'll save you a few bucks:

All of the fuel pressure test kits above have the adapter that'll connect to your minivan's fuel pressure test port (Schrader valve).

Fuel Pressure Specifications

• KOEO = Key On Engine Off.
• KOER = Key On Engine Running.

Fuel Pressure Test With A Gauge

The spot where you'll hook up the fuel pressure test gauge is the Schrader valve right on the fuel injector rail. If you look at the photo above, you'll see the Schrader valve with its dust cap on (it's located under the intake manifold plenum).

If your minivan's fuel pump is doing its job, the gauge will show a pressure reading that lines up with the PSI specs listed here: Fuel Pressure Specifications.

If the pump's faulty, expect a reading at or below 0 PSI. OK, let's get started:

1. 1

   Disconnect the ignition coil from its electrical connector.
   
   NOTE: This step only applies if the engine starts and runs.

2. 2

   Remove the dust cap from the Schrader valve on the fuel injector rail.

3. 3

   Place a towel under the area of the Schrader valve.

4. 4

   Connect the fuel pressure gauge to the Schrader valve.
   
   Use a towel to dry any fuel that may have been released during the gauge connection process.

5. 5

   When you're ready, have your assistant crank the engine while you observe the pressure gauge.

6. 6

   The gauge should display the specified fuel pressure.

Let's analyze your test result:

CASE 1: The fuel pump pressure is within specification. This tells you the fuel pump is in good working condition and supplying fuel to the injectors.

If the engine doesn't start, then this test result rules out the fuel pump as the source of the engine's 'cranks but does not start' issue.

CASE 2: The fuel pump pressure is NOT within specification. This result tells you that the fuel pump is not functioning. Since the fuel pump isn't working, you can now conclude that it's behind the 'cranks but does not start'.

Using Starting Fluid To Check For A Lack Of Fuel

The starting fluid test is a classic -it's been around since cars had carburetors. It's one of my favorites for troubleshooting an engine no-start problem.

In a nutshell, it simply involves spraying some starting fluid into the throttle body, getting a helper to crank the engine, and then watching if the engine starts.

If the engine starts and runs for a seconds, it's a fuel problem. If not, look elsewhere for the cause of the engine's no-start issue.

IMPORTANT: This test is accurate only when all four spark plug wires are delivering spark to their spark plugs, so test them for spark with a spark tester before you begin.

OK, here are the test steps:

1. 1

   Remove the intake air duct from the throttle body.
   
   You don't have to remove it completely as you'll need to reconnect it in one of the following steps.

2. 2

   Manually open the throttle plate and spray starting fluid into the throttle body bore.

3. 3

   Quickly reconnect the air duct to the throttle body (no need to tighten the hose clamp).
   
   NOTE: Reconnecting the intake air duct is a very important safety precaution in case of backfire through the intake manifold.

4. 4

   Crank the engine once the intake air duct is back on the throttle body.

5. 5

   You'll get one of two results:
   
   1.) The engine will briefly start, run and then shut off after a few seconds.
   
   2.) The engine cranks but doesn't start at all.

Alright, let's figure out what it all means:

CASE 1: The engine started and ran for a few seconds. This confirms that the issue of your vehicle cranking but not starting is due to a lack of fuel.

I suggest your next step should be testing the fuel pump pressure with a pressure gauge. For this test, go to: Fuel Pressure Test With A Gauge.

CASE 2: The engine did NOT start, not even briefly. This indicates that a lack of fuel is not the reason why the engine won't start.