How To Test The Fuel Injectors (2.0L Ford Escort)

How To Find The Bad Or Clogged Fuel Injector

Finding the clogged or bad fuel injector can seem difficult or even impossible. Thankfully, there's a logical process that we can follow to find it.

I've used the following troubleshooting strategy with a lot of success and I think it'll help you too. The most important first step is to identify the 'dead' cylinder first:

1. Find the 'dead' cylinder first.
   • This requires checking for specific misfire codes (P0301, P0302, P0303,P0304) or doing a cylinder balance test.
2. Once the 'dead' cylinder has been identified, the next step is to make sure it's getting spark.
   • You must use a dedicated spark tester to check for spark.
   • It's important that you check that the spark plug boot and spark plug are NOT soaked (or swimming) in engine oil (this is especially true on the 2.0L DOHC engines where the spark plug sits right on top of the cylinder head).
   • You should also remove the spark plug and check it for cracks or carbon tracks (this is SO important).
     • Here's a real life case study on carbon tracks and how they can cause a misfire: Carbon Tracks Are A Common Cause Of Ignition Misfires.
   • The key here is to eliminate the ignition coil, the spark plug wire and the spark plug as the cause of the cylinder's misfire.
     • The following tutorial will show you how to test the spark plug wires and the ignition coil: How To Test The 4 Cylinder Coil Pack (Ford 1.9L, 2.0L).
3. If spark is present, then the next step is checking that that cylinder has good compression.
   • This is one of the most overlooked tests when diagnosing a misfire or rough idle condition. You can find the test here:
     • How To Test Engine Compression (2.0L Ford).
4. Noid light test.
   • If every test above checks out OK, then the next step is to do a fuel injector Noid light test.
   • The Noid light test will help you make sure that the fuel injector is being activated.
   • The following Noid light article/tutorial may help you: How To Use A Noid Light And Where To Buy It (I know that this is not the most in-depth article on the subject, but it should give you an idea of what is involved).

5. Swap the fuel injector with its neighbor on the fuel injector rail.
   • I'll swap out that fuel injector with its neighbor only if:
     1. The ignition system is not at fault.
     2. That cylinder's compression value is good (compared to the rest of the cylinders).
     3. The fuel injector resistance is good.
     4. I think the fuel injector is clogged.
     If the misfire now follows that swap, I now know that fuel injector is clogged (or bad) and needs to be cleaned or replaced.

Finding the bad/clogged fuel injector can be a challenge on your Ford 2.0L Escort (Focus) but it's doable. What will help you save a lot of time, money and frustration is to first find the 'dead' cylinder. Following the above diagnostic strategy has saved my lunch quite a few times and I think it'll help you too!

More 2.0L Ford Diagnostic Tutorials

You can find a complete list of 2.0L Ford Escort (Focus) tutorials in these two indexes:

• Ford 2.0L Index Of Articles.
• Ford 1.9L, 2.0L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test Engine Compression (2.0L Ford).
• MAF Sensor Test 2.0L Escort, Tracer (1997-2002).
• How To Test The Ford EGR Valve EGR Vacuum Solenoid, DPFE Sensor.
• How To Test The Crankshaft Position Sensor (Ford 1.9L, 2.0L) (at troubleshootmyvehicle.com).