How To Test The Fuel Pump (1995-2000 1.6L Honda Civic)

Testing the fuel pump has become a whole lot easier, now that you can find a fuel pressure gauge test kit with the necessary adapter to tap into the fuel pressure line on your 1.6L Honda Civic.

In this tutorial I'm gonna' I'll explain the fuel pressure test and also how to check for a lack of fuel with starting fluid.

You can find this tutorial in Spanish here: Cómo Probar La Bomba De Combustible (1995-2000 1.6L Honda Civic) (at: autotecnico-online.com).

APPLIES TO: This manifold absolute pressure (MAP) sensor circuit wiring diagram applies to the following vehicles:

• 1.6L Honda Civic CX: 1995, 1996, 1997, 1998, 1999, 2000.
• 1.6L Honda Civic DX: 1995, 1996, 1997, 1998, 1999, 2000.
• 1.6L Honda Civic EX: 1995, 1996, 1997, 1998, 1999, 2000.
• 1.6L Honda Civic LX: 1995, 1996, 1997, 1998, 1999, 2000.

RELATED WIRING DIAGRAMS:

• Fuel Pump Circuit Wiring Diagram (1995 1.6L Honda Civic).
• Fuel Pump Circuit Wiring Diagram (1996-1998 1.6L Honda Civic).
• Fuel Pump Circuit Wiring Diagram (1999-2000 1.6L Honda Civic).
• PGM-FI Main Relay Circuit Diagram (1996-1998 1.6L Honda Civic).

The fuel pump gets power from the PGM-FI Main Relay. If you find that you need to test the PGM-FI Main Relay, you can find the test tutorial here:

• How To Test The PGM-FI Main Relay (1996-1998 1.6L Honda Civic).

Symptoms Of A Bad Fuel Pump

A bad fuel pump doesn't necessarily mean that it has stopped working (and keeping your Civic from starting). Sometimes a fuel pump fails slowly, where it works but doesn't send enough fuel volume to the fuel injectors.

Obviously, when the fuel pump completely fails your 1.6L Honda Civic isn't gonna' start. In this type of scenario, you'll see that:

1. The engine turns over but will not start.
2. The distributor is feeding spark to all 4 cylinders.
3. The PCM will still pulse (activate) all of the fuel injectors.

But when the fuel pump sends a lower than normal volume of fuel, the air/fuel mixture will run very lean and cause quite a few performance issues. You'll probably see one or more of the following symptoms:

1. Rough idle.
2. Engine starts after extended cranking.
3. Lack of power when accelerating the vehicle down the road.
4. Back-fires thru' the intake manifold when accelerating your car down the road.

Both of these conditions can be tested with a fuel pressure gauge. Alright, with this info under our belts, let's get testing.

NOTE: If you're troubleshooting an engine no-start issue, the following guide is a good diagnostic resource:

• How To Troubleshoot A No Start (1995-2000 1.6L Honda Civic).

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 include the banjo-bolt test adapter:

NOTE: Before choosing a fuel pressure test gauge, you need to know what type of banjo bolt sits on top of the fuel filter. For more info see the next section: Type Of Banjo Bolt On Fuel Filter.

TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge

A fuel pressure test gauge, with the necessary adapter to tap into your Civic's fuel system, is not expensive. This is good news because using a fuel pressure test gauge is the best way to test the condition of the fuel pump (don't have one, take a look at: Where To Buy A Fuel Pressure Test Gauge).

So, in this test section, we'll use a fuel pressure test gauge to check the fuel pump's output pressure. The fuel pressure specification for your Honda Civic, if it starts and runs, is: 30 to 37 PSI (with the fuel pressure regulator's vacuum hose connected) and 38-47 PSI (with the fuel pressure regulator's vacuum hose disconnected.).

If your Civic's engine doesn't start, you should look for the fuel pressure to be somewhere between 38-47 PSI (whether the vacuum hose is connected or disconnected from the fuel pressure regulator).

Lastly, the fuel pressure gauge is connected to the fuel system by using an adapter that connects to the fuel filter's banjo bolt (also known as just the union bolt) (see photo above).

OK, let's get started with this test:

1. 1

   Disconnect the distributor from its electrical connector.
   
   This is just a safety precaution and will prevent the engine from starting.

2. 2

   Place a shop towel around the fuel filter's banjo bolt. The shop towel's job is to absorb any fuel that may leak when doing step 3.

3. 3

   Remove the 6mm bolt located on top of the fuel filter's banjo bolt. Now, connect the fuel pressure test gauge to adapter to the fuel filter's banjo bolt.
   
   NOTE: Use the appropriate adapter that applies to the particular banjo bolt type of your 1.6L Honda Civic (since some 1.6L Civic's don't use the 6mm bolt on top of the fuel filter's banjo bolt). For more info about this see: Type Of Banjo Bolt On Fuel Filter.

4. 4

   When ready, ask your helper to cycle the key on and off but don't crank the engine while you observe the fuel pressure tester's gauge.

5. 5

   Check the connection at the fuel filter for fuel leaks and if any, eliminate them.

6. 6

   Have your helper crank the engine. The engine will not start since the distributor is disconnected from its electrical connectors.

7. 7

   Your fuel pressure gauge should register: 38 to 47 PSI with the Key On Engine Off (KOEO) if the fuel pump is OK.

Let's take a look at what your results mean:

CASE 1: If the fuel pressure gauge registered 0 PSI. This confirms that the cause of your 1.6L Honda Civic engine's no-start problem is caused by a lack of fuel.

Now, I usually take one more precaution, before condemning the fuel pump as bad and this is to check that the fuel pump is getting 12 Volts as the engine is cranking. This is just to make sure that the fuel pump relay and fuse are OK and doing their job.

What you'll have to do to accomplish this is to attach a multimeter in Volts DC mode to the wire that supplies this voltage to the fuel pump and while a helper cranks the engine, you'll verify that the fuel pump is getting this power. If the 12 Volts are being supplied to the fuel pump, you have now 100% verified that the fuel pump is fried and needs to be replaced.

CASE 2: If the fuel pressure gauge registered 38 to 47 PSI: This fuel pressure gauge result lets you know that the fuel pump is working and delivering enough fuel to the fuel injectors.

The reason your 1.6L Honda Civic is not starting is due to another reason. The fuel pump is OK. See:

• How To Troubleshoot A No Start (1995-2000 1.6L Honda Civic).

TEST 2: Using Starting Fluid To Confirm Lack Of Fuel

Although this test is not the most accurate way of testing a bad fuel pump (causing a no-start problem), it will 'jump start' your troubleshooting efforts and narrow down the list of possible bad components.

The idea behind the starting fluid test, is to see if the engine will start after spraying starting fluid into your Civic's engine's throttle body.

But before you do this test, it's crucial that you first check that all four spark plug wires are sparking. You can easily accomplish this by attaching a spark tester to the spark plug wires and having a helper crank the engine (while you observe to see if the spark tester sparks). If the spark plug wires are not sparking, then this test will not work, not to mention that a no spark test result tells you that the problem is in the ignition system.

IMPORTANT: This is a very fast and easy test but you do have to take one very important safety precaution and this is to reconnect the air intake duct after spraying starting fluid down the throttle bore (although you don't have to fasten it). This will prevent any backfire, that might occur, from scaring the heck out of you when cranking the engine.

This is what you have to do:

1. 1

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

2. 2

   Open the throttle plate and spray starting fluid down the bore.
   
   As a safety precaution reconnect the air duct after you have sprayed a good squirt of starting fluid (but you don't have to tighten the air duct's hose clamp).

3. 3

   Crank the engine once the air duct is back on and you're clear of the engine compartment.

4. 4

   You'll get one of two results with this test:
   
   1.) The engine will start momentarily and after a few seconds will die or.
   
   2.) The engine will only crank but not start at all.

OK, let's find out what your results mean:

CASE 1: If the engine started and ran for a few seconds. This test result tells you that the no-start problem is due to a lack of fuel.

Your next step is to check to see what the fuel pressure is with a fuel pressure test gauge. Go to: TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge.

CASE 2: The engine did not start, not even momentarily. This usually means that a lack of fuel IS NOT the reason your car is not starting.

Now, remember what I said about this test not being very accurate? Well, I suggest you do one more test and this is to check the fuel pressure with a fuel pressure test gauge. Go to: TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge.

Type Of Banjo Bolt On Fuel Filter

NOTE: Before you buy a fuel pressure test gauge, you need to find out what type of banjo bolt connects the fuel line (between the fuel filter and fuel injector rail) on your 1.6L Honda Civic. Why? Because the fuel pressure test gauge you may buy may not have the proper fitting to test the fuel pump.

There are two types of banjo bolts used:

• One banjo bolt has a 6mm bolt on top of it (see photo above).
• The other banjo bolt does not have a 6mm bolt on top of it (see photo below).

The ADT Tools 5567 Basic Fuel Injection Pressure Tester will only test Hondas with the 6mm bolt on top of the fuel banjo bolt.

The Great Neck OEM 27167 Fuel Pressure Test Kit and the Wilmar W89726 Master Fuel Injection Test Kit will test all Hondas regardless of the type of banjo bolt.

Where To Buy The Fuel Pump And Save

The fuel pump in your 1.6L Honda Civic is located inside the fuel tank. The fuel pump can be bought in any auto parts store, but I think you'll find the better price online. The following fuel pumps are pretty good deals:

Not sure if the above fuel pumps fit your particular 1.6L Honda Civic? Don't worry, once you get to the site, they'll make sure it fits by asking you the specifics of your vehicle. If it doesn't fit, they'll find you the right one.

More 1.6L Civic Tutorials

You can find a complete list of tutorials and wiring diagrams in this index:

• 1.6L Honda Civic Index Of Articles.

Here's a small sample of the 1.6L Honda Civic tutorials you'll find in the index:

• Testing Shift Control Solenoid Valves A and B (1996-2000 1.6L Honda Civic).
• How To Test The Alternator (1996-2000 1.6L Honda Civic).
• How To Test: Lock-up Control Solenoid Valves (1996-2000 1.6L Honda Civic).
• How To Test Trouble Code P0135 (1995-2000 Honda 1.6L).
• How To Test The Igniter, Ignition Coil Accord, Civic, CRV, and Odyssey (at:easyautodiagnostics.com).