A bad fuel pump will cause your 3.3L V6 Chrysler (Dodge or Plymouth) mini-van to not start due to a lack of fuel to the fuel injectors.
A failing fuel pump will cause major engine performance issues, even though the engine starts and runs.
Thankfully, the fuel pump can easily be tested with a fuel pressure test gauge and in this tutorial I'll explain how to do it.
Contents of this tutorial:
- Symptoms Of A Bad Fuel Pump.
- Where To Buy A Fuel Pressure Test Gauge.
- TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge.
- TEST 2: Using Starting Fluid To Confirm Lack Of Fuel.
- Making Sure The Fuel Pump Is Getting 12 Volts.
- Identifying The Fuel Pump Relay.
- More 3.3L V6 Chrysler, Dodge, And Plymouth Mini-Van Tutorials.
You can find this tutorial in Spanish here: Cómo Probar La Bomba De Combustible (1992-1993 3.3L V6 Chrysler, Dodge, Plymouth Mini-Van) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following 3.3L V6 equipped Chrysler, Dodge, and Plymouth mini-vans:
- 3.3L V6 Chrysler Town & Country: 1992, 1993.
- 3.3L V6 Dodge Caravan: 1992, 1993, 1994, 1995.
- 3.3L V6 Dodge Grand Caravan: 1992, 1993.
- 3.3L V6 Plymouth Voyager: 1992, 1993.
- 3.3L V6 Plymouth Grand Voyager: 1992, 1993.
Symptoms Of A Bad Fuel Pump
A fuel pump generally fails in one of two ways:
- The fuel pump suffers a complete failure.
- The fuel pump starts to fail but doesn't fail completely.
Here are some specific symptoms of when a fuel pump completely fails.
- The engine turns over but will not start.
- All 6 spark plug wires are sparking (confirming it's not an ignition system problem).
- The PCM will still pulse (activate) all 6 fuel injectors (as confirmed by a Noid light test).
But when the fuel pump is failing (but hasn't failed completely), your 3.3L V6 Chrysler (Dodge or Plymouth) mini-van will start and run but with engine performance problems. You'll probably see one or more of the following symptoms:
- Rough idle.
- Engine starts after extended cranking.
- Lack of power when accelerating the vehicle down the road.
- Back-fires thru' the intake manifold when accelerating your vehicle down the road.
- Lean air/fuel mixture trouble codes: P0171 or P0174 or both.
Whether the fuel pump is the cause behind your 3.3L V6 Chrysler (Dodge or Plymouth) mini-van's no-start problem or engine performance problem, you can find out with a simple fuel pump pressure test. Alright, with this info under our belts, let's get testing.
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 following fuel pressure test gauge kits are pretty good deals and will work with your 3.3L V6 Chrysler (Dodge or Plymouth) mini-van:
All of the fuel pump pressure test kits above have the fitting that will connect to your Dodge's Schrader valve.
TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge
In the photo above is pictured the Schrader valve and this valve is what makes testing the fuel pump a piece of cake.
It's to this valve, which is located on the fuel injector rail facing the radiator, that we're going to connect the fuel pressure test gauge to.
If the fuel pump is functioning correctly, you should see a fuel pressure specification of: 48 PSI with the key on and engine off and the fuel pump activated.
NOTE: If you don't have a fuel pressure gauge, take a look at the section: Where To Buy A Fuel Pressure Test Gauge.
CAUTION: The test instructions below will ask you to jumper together two female terminals of the fuel pump relay socket. Be careful and do not insert anything into the female terminals that is wider than the male terminals that connect to them, or you run the risk of damaging them.
OK, let's get started with this test:
Place a shop towel around the Schrader valve. The shop towel's job is to absorb any fuel that may leak when doing step 2.
Connect the fuel pressure gauge to the Schrader valve on your 3.3L V6 Chrysler (Dodge or Plymouth) mini-van's fuel injector rail.
Locate the fuel pump relay and disconnect it from its electrical connector.
You can identify the fuel pump relay by the colors of the wires that connect to it. For more info see this section: Identifying The Fuel Pump Relay.
Jumper together fuel pump relay socket female terminals 1 and 2 with a jumper wire (see photo 2 of 2 above).
The green with orange stripe wire (GRN/ORG) wire connects to female terminal labeled with the number 1.
The red with white stripe (RED/WHT) wire connects to female terminal labeled with the number 2.
The fuel pump will activate.
At this point check the connection at the Schrader valve for fuel leaks and if any tighten the fuel pressure tester a bit more (by hand only) to eliminate them.
Your fuel pressure gauge should register: 48 PSI.
Let's take a look at what your results mean:
CASE 1: The fuel pressure gauge registered 0 PSI. This test result lets you know that the no-start problem is caused by a lack of fuel from the fuel pump.
Take a look at the suggestion found here: Making Sure The Fuel Pump Is Getting 12 Volts.
CASE 2: The fuel pressure gauge registered a pressure below the indicated PSI. This test result lets you know that the fuel pump is failing.
CASE 3: The fuel pressure gauge registered the indicated PSI. This is the correct test result.
With this test result you can conclude that the fuel pump is working and delivering enough fuel to the fuel injectors. You can also conclude that your 3.3L V6 Chrysler (Dodge or Plymouth) mini-van is not starting due to another reason. The fuel pump is OK.