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.
Contents of this tutorial:
- Symptoms Of A Bad Fuel Pump.
- TEST 1: Using Starting Fluid To Confirm Lack of Fuel.
- TEST 2: Checking Fuel Pressure With A Fuel Pressure Gauge.
- Location Of The Fuel Filter's Banjo Bolt.
- Where To Buy A Fuel Pressure Test Gauge.
- Where To Buy The Fuel Pump And Save.
- More 1.5L Honda Civic Diagnostic Tutorials.
You can find this tutorial in Spanish here: Cómo Verificar la Bomba de Combustible (1.5L Honda Civic) (at: autotecnico-online.com).
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.
TEST 1: 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:
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.
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).
Crank the engine once the air duct is back on and you're clear of the engine compartment.
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 2: 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 2: Checking Fuel Pressure With A Fuel Pressure Gauge.