How To Test The Fuel Pump (1994-1995 3.0L V6 Dodge And Plymouth Minivan)

A bad or failing fuel pump could be the culprit behind an engine no-start or power loss issue on your 1994-1995 3.0L V6 minivan.

In this tutorial, I'll show you two key tests —a fuel pressure gauge test and a starting fluid test —that'll help you zero in on the problem.

Whether your minivan won't start at all or just bogs down when driving, these step-by-step checks will help you confirm if the fuel pump is to blame.

APPLIES TO: This tutorial applies to the following vehicles:

• 3.0L V6 Dodge Caravan: 1994, 1995.
• 3.0L V6 Dodge Grand Caravan: 1994, 1995.
• 3.0L V6 Plymouth Voyager: 1994, 1995.
• 3.0L V6 Plymouth Grand Voyager: 1994, 1995.

FUEL PUMP TEST TUTORIALS:

• How To Test The Fuel Pump (1996-1999 3.0L V6 Dodge And Plymouth Minivan).
• How To Test The Fuel Pump (2000 3.0L V6 Dodge And Plymouth Minivan).

Symptoms Of A Bad Fuel Pump

As you already know, the fuel pump is what keeps fuel moving from the tank up to the engine. If it stops doing its job right, your engine either won't start at all, or it'll run like it's being starved for power.

When the pump completely fails, you'll crank the engine, but it won't fire up —no fuel means no combustion.

Other times, the pump's performance degrades instead of dying outright. When that happens, the engine might start, but it'll stall when you stick it in Drive and step on the gas. In this case, stuff like accelerating, towing, or even when the A/C kicks on affects engine performance.

These are the red flags to watch out for when the fuel pump's on its way out:

• Rough idle: Rough or shaky idle when stopped.
• Extended engine cranking: It takes longer than usual to start the engine.
• Lack of power: Noticeable lack of acceleration power.
• Backfires:+ Backfiring through the intake manifold —especially when giving it gas.
• Code 51: Check engine light is on with code 51 —lean condition due to low fuel delivery.

Where To Buy A Fuel Pressure Test Gauge

The 3.0L V6 minivan isn't equipped with a Schrader valve test port for checking fuel pressure. Instead, the rubber supply hose connects directly to the fuel injector rail's inlet line and is secured with a simple hose clamp.

To test the fuel pressure, you'll need an adapter called a "double-ended barbed hose adapter". This adapter goes between the fuel supply hose and the fuel injector rail's inlet line.

The fuel pressure test kits below include the double-ended barbed hose adapter you'll need to get the job done:

All of the fuel pump pressure test kits above have the fitting that will connect to your Dodge's Schrader valve.

Fuel Pressure Specifications

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

TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge

The easiest way to check fuel pressure is with a scan tool that can command the fuel pump on (not to mention it's what the manual calls for).

If you've got one, great —use it, it's a time saver. But if you don't, no worries. You can still test the fuel pump by bypassing the fuel pump relay manually.

It's quick, effective, and I'll show you how to do it so that you can activate the fuel pump with the key OFF and check its pressure.

IMPORTANT: Don't use a jumper wire that's thicker than the fuel pump relay's terminals —forcing it in can stretch or damage the socket connectors inside the fuse box, and that's a nightmare you don't want to deal with.

These are the test steps:

1. 1

   Slipping a shop towel under the fuel hose where it joins the injector rail —this'll help catch any fuel drips and keep things safe.

2. 2

   Next, disconnect the rubber fuel line from the injector rail's inlet side.

3. 3

   Connect the double-ended barbed hose adapter using the short rubber hose to the fuel rail inlet and secure it with its hose clamp.

4. 4

   Reconnect the supply hose to the other side of the double-ended barbed hose adapter and clamp it down too.

5. 5

   Now hook up your fuel pressure gauge to the hose adapter.

6. 6

   Pop the hood fuse box open and pull out the fuel pump relay.

7. 7

   Use a jumper wire to connect terminals 30 and 87 in the relay socket.
   
   NOTE: This will activate the fuel pump immediately.
   
   Watch for any leaks around your hose clamps and fittings.
   
   If fuel is leaking, remove the jumper wire (to deactivate the fuel pump) and tighten up the clamps a bit more.

8. 8

   The pressure gauge should read right around 48 ± 2 PSI with the fuel pump activated.

Let's interpret your fuel pump pressure test result:

CASE 1: Fuel pressure hits the target (around 48 ± 2 PSI). That means the fuel pump is working fine.

If the engine still won't start or is running rough, you've got to look elsewhere —this pump isn't the problem.

CASE 2: Fuel pressure is low —way below spec. That's the classic sign of a weak fuel pump.

The engine might start and still run, but not well. Time to replace the fuel pump.

CASE 3: No pressure at all (0 PSI). The fuel pump is not delivering any fuel.

Now, we need to make sure that terminal 30 (of the relay socket) has 10 to 12 Volts. Go to: Checking The Fuel Pump Fuse.

TEST 2: Using Starting Fluid To Diagnose A No-Start Condition

This test is one of the quickest and easiest ways to figure out if your minivan's engine no-start issue is fuel-related.

It doesn't require any tools besides a can of starting fluid (carb cleaner and brake cleaner spray will work too) and a bit of common sense —and it can save you a lot of time chasing the wrong problem.

Here's what you're looking for: if the engine fires up and runs for a couple seconds after spraying starting fluid into the throttle body, you're dealing with a fuel delivery issue.

With this test result you can also conclude that the engine has spark and compression —it just isn't getting fuel.

But if the engine doesn't respond at all —no sputter, no pop, nothing— then you're not dealing with a fuel problem. In that case, it's time to check for compression issues, etc.

IMPORTANT: The accuracy of this test depends on all six spark plug wires firing spark. So before you reach for the carb cleaner or starting fluid, confirm that all six cylinders are getting spark.

Let's get testing:

1. 1

   Pop the intake hose off the throttle body.
   
   Just enough to open up access to the throttle bore.

2. 2

   Open the throttle plate and spray a good and quick shot of starting fluid directly into the throttle opening.

3. 3

   Slip the hose right back on.
   
   You don't need to tighten the clamp —just make sure the hose is seated well enough so the engine can draw air through it.

4. 4

   Have a helper crank the engine as soon as the hose is back on.

5. 5

   Watch what happens next:.
   
   1.) Either the engine will briefly fire up and then stall or...
   
   2.) The engine won't start at all.

Depending on your result, here's what's going on:

CASE 1: Engine started and then shut off. This confirms that the engine can run when given fuel —which means the ignition system and engine mechanical health are fine.

The fuel system, specifically the pump, isn't delivering what the engine needs. Your next step should be to check fuel pressure directly using a gauge: TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge.

CASE 2: Engine cranked but didn't start at all. If it didn't even try to fire up, you're not dealing with a fuel delivery issue.

Something else —like a sensor issue, compression, or a timing problem— is keeping the engine from firing.

Checking The Fuel Pump Fuse

If your fuel pressure gauge shows zero PSI in TEST 1, the next step is to check whether the fuel pump is getting power —because without it, the pump won't run.

The voltage that powers the pump comes from terminal 30 of the fuel pump relay socket. This terminal is supposed to have 10 to 12 Volts at all times —even with the key off.

This "always ON" voltage is fed by fuse #10 (15 amp) located in the same Power Distribution Center as the fuel pump relay.

Grab a multimeter or test light and probe terminal 30. If there's no voltage, remove fuse #10 and check it.

If the fuse is blown, replace it. But head's up —a blown fuse is your first clue that the fuel pump is drawing too much current, which often means it's on its way out.

So, if you replace the fuse and it blows again (even if the engine starts and runs), that's a sure sign of a failing fuel pump.

If the fuse is intact, you've got 10 to 12 Volts at terminal 30, and still no fuel pressure? Then the pump has failed and needs to be replaced.

More 3.0L V6 Dodge And Plymouth Minivan Tutorials

You can find a complete list of 3.0L V6 Dodge and Plymouth minivan tutorials in this index:

• 3.0L V6 Dodge And Plymouth Minivan Index Of Articles.

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

• How To Replace The Distributor (1988-2000 3.0L V6 Chrysler, Dodge, Plymouth).
• How To Test For A Broken Timing Belt (1988-2000 3.0L SOHC Chrysler).
• How To Test Engine Compression (1987-2000 3.0L V6 Chrysler, Dodge, Plymouth).
• How To Test For A Blown Head Gasket (1991-2000 3.0L Caravan, Grand Caravan, Voyager, Grand Voyager).