How To Test The Fuel Pump (1992-1995 1.5L Honda Civic)

You can accurately test the condition of your fuel pump using a fuel pressure gauge. In this tutorial, I'll explain the 2 most common methods of checking the fuel pump.

I'll also show you where you can buy a fuel pressure gauge that has the adapter to test your Honda Civic.

Alright, let's get started and find out if the fuel pump has failed and causing a 'cranks but does not start' condition.

You can find this tutorial in Spanish here: Cómo Verificar La Bomba de Combustible (1.5L Honda Civic) (at: autotecnico-online.com).

FUEL PUMP WIRING DIAGRAM: The following fuel pump circuit wiring diagram may come in handy:

• Fuel Pump Circuit Wiring Diagram (1992-1995 1.5L Honda Civic).

Symptoms Of A Bad Fuel Pump

Fuel pump failures usually fall in one of two categories. The most common is a complete failure of the fuel pump that prevents your 1.5L Honda Civic from starting.

The other is a fuel pump suffering a 'slow death' that isn't able to send the correct volume of fuel to the fuel injectors (in this case the car starts but runs badly).

Obviously, when the fuel pump completely fails your 1.5L Honda Civic isn't gonna' start. In this type of scenario, you'll see that:

• The engine turns over but will not start.
• The ignition coil pack is creating and distributing spark to all 6 cylinders.
• The PCM will still pulse (activate) all 6 fuel injectors.

But when the fuel pump sends a lower than normal volume of fuel, your 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 pickup or van 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 diagnosing an engine no-start issue, the following guide is a good troubleshooting guide:

• How To Troubleshoot A No Start (1992-1995 1.5L 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 for your Honda Civic:

TEST 1: Checking Fuel Pressure With A Fuel Pressure Gauge

It used to be that to test the fuel pressure on any Honda, you had to buy a very expensive professional fuel pressure test gauge kit. One that usually had all of the adapters for all domestic and import makes and models and that usually cost more than US$300.00!

Within the past few years, as the DIY market has exploded, fuel pressure gauges have come down in price a lot and you don't need to buy an expensive fuel pressure gauge test kit.

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, from the Honda Civic repair manual, is 30 to 35 PSI.

We can connect a fuel pressure gauge to the fuel system using an adapter that connects to the fuel filter's banjo bolt (see photo above). You can see a photo of the fuel filter's banjo bolt here: Location Of The Fuel Filter's Banjo Bolt.

NOTE: If you don't have a fuel pressure gauge, take a look at the section: Where To Buy A Fuel Pressure Test Gauge.

OK, let's get started with this test:

1. 1

   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 2.

2. 2

   Remove the 6mm bolt located on top of the fuel filter's banjo bolt..

3. 3

   Now, screw the fuel pressure test gauge's adapter in the 6mm bolt's hole (on the banjo bolt).
   
   NOTE: You don't have to remove the banjo bolt from the fuel filter if you have the small 6mm adapter. If you're using a test gauge kit without the 6mm adapter and instead using an adapter the same size as the banjo bolt, then watch out for the 2 copper washers that are used on the fuel filter's banjo bolt. As you remove the banjo bolt, be careful they don't fall and get lost since they're the ones that seal the fuel within the connection.

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

5. 5

   Your fuel pressure gauge should register: 30 to 45 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 1.5L 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, 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.

The following wiring diagram will help you locate the fuel pump fuse: Fuel Pump Circuit Wiring Diagram (1993-1995 1.5L Honda Civic).

CASE 2: The fuel pressure test shows 30 to 45 PSI. This reading confirms the fuel pump is running and sending the right amount of fuel up to the injectors.

So if your 1.5L Honda Civic still won't start, the cause lies elsewhere. The fuel pump checks out fine. Take a look here:

• No-Start Troubleshooting Guide (1992-1995 1.5L Honda Civic).

TEST 2: Using Starting Fluid To Confirm Lack Of Fuel

Using starting fluid, to check for a 'lack of fuel' condition, is probably the oldest trick in the book.

Although it's the easiest/fastest way to check to see if a lack of fuel is causing your 1.5L Honda Civic to no-start, let me tell you that it's not the most accurate way of diagnosing a bad fuel pump. Still, this test is very handy and is usually the first test I have performed to check for a bad fuel pump.

The one thing you need to keep in mind, is that if your Civic starts after you've sprayed starting fluid into its throttle body even if momentarily, then this tells you that fuel is not being sprayed into the cylinders.

NOTE: To get an accurate test result from the starting fluid test, you need to first confirm that spark is reaching all 4 cylinders. 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).

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: 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.

Location Of The Fuel Filter's Banjo Bolt

Where To Buy The Fuel Pump And Save

The fuel pump in your 1.5L 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 1.5L 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 1.5L Honda Civic Diagnostic Tutorials

If this tutorial was helpful/informative, you can find a complete list of tutorials here: 1.5L Honda Civic Index Of Articles.

Here's a sample of the tutorials you'll find there:

• How To Test The MAP Sensor (Honda 1.5L).
• How To Test The Fuel Injectors (Honda 1.5L, 1.6L).
• How To Test The Throttle Position Sensor (1992-1995 1.5L Honda Civic).
• How To Test The Igniter, Ignition Coil Accord, Civic, CRV, and Odyssey (at: easyautodiagnostics.com).