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.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar La Bomba De Combustible (1995-2000 1.6L Honda Civic) (at: autotecnico-online.com).
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:
- The engine turns over but will not start.
- The distributor is feeding spark to all 4 cylinders.
- 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:
- 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 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.
TEST 1: 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:
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.