In this tutorial, I'll walk you through the process of testing the fuel injectors on the 1992-1996 2.2L Toyota Camry for internal short-circuit or open-circuit problems using a multimeter to resistance test them.
With the step-by-step instructions I'm outlining in this tutorial, you'll be able to find out whether a faulty fuel injector is causing problems with your Camry's engine performance.
All of the test steps are explained in a step-by-step manner so you can find out if you've got one that has failed.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 2.2L Toyota Camry: 1992, 1993, 1994, 1995, 1996.
Wiring Diagrams:
- Fuel Injectors Circuit Wiring Diagram (1992-1993 2.2L Toyota Camry).
- Fuel Injectors Circuit Wiring Diagram (1994-1995 2.2L Toyota Camry).
- Fuel Injectors Circuit Wiring Diagram (1996 2.2L Toyota Camry).
1997-2001 Fuel Injector Tests:
Symptoms Of A Bad Fuel Injector
The fuel injectors in your Toyota Camry play a critical role in delivering the right amount of fuel to each cylinder for proper combustion. Over time, these injectors can fail, and their failure usually falls into one of two categories:
- Stops injecting fuel completely: This happens when the injector's internal electrical circuit fails or the injector becomes stuck closed.
- Becomes clogged: Debris, carbon buildup, or contaminants in the fuel can partially or fully block the injector nozzle, restricting fuel flow.
When one or more fuel injectors fail, you'll see one or more of the following symptoms of fuel injector failure:
- Rough idle: A failing or clogged injector will disrupt its cylinder's air-fuel mixture, causing uneven combustion. This results in noticeable shaking or vibration while the engine idles.
- Lack of power: A faulty injector that doesn't deliver enough fuel will leave its cylinder underpowered. This causes sluggish performance, reduced acceleration, and a sense that the engine is "struggling" to keep up.
- Engine hesitates when accelerating under load: A malfunctioning injector can cause the engine to stutter or jerk during acceleration, feeling like it's briefly "choking" before catching up.
- Cylinder misfire trouble codes (OBD II equipped):
- P0300: Random Cylinder Misfire.
- P0301: Misfire In Cylinder #1.
- P0302: Misfire In Cylinder #2.
- P0303: Misfire In Cylinder #3.
- P0304: Misfire In Cylinder #4.
Whether a fuel injector has an internal electrical issue or is clogged, this tutorial will help you find out.
START HERE: How To Find The Bad Or Clogged Fuel Injector
Finding the clogged fuel injector isn't that much more difficult. In this test section, I'll explain my method for finding the fuel injector that's clogged and causing a misfire or a rough idle problem.
To find the clogged (or bad) fuel injector on your Toyota Camry, requires doing a set of tests. Each test is designed to eliminate a possible issue as the source of the misfire.
These are the steps of my testing strategy:
- Identify the "dead" cylinder first:
- Identifying which of the four cylinders is "dead" is the most important first step!
- On the 1992-1995 OBD I Camry, this means performing a manual cylinder balance test to identify the "dead" cylinder.
- On the 1996 OBD II Camry, the "dead" cylinder can be identified using an automotive scan tool or code reader to extract the cylinder misfire trouble code.
- Verify that the "dead" cylinder is getting spark:
- Use a spark tester to check for spark at the spark plug wire.
- Check for engine oil around the spark plug boot and spark plug. If the spark plug is swimming in oil, you've most likely have found the cause of the cylinder misfire.
- Inspect the spark plugs for cracks or carbon tracks. See this tutorial for more info on carbon tracks:
- Carbon Tracks Are A Common Cause Of Ignition Misfires (at: easyautodiagnostics.com)
- Check the "dead" cylinder's compression:
- Verify the "dead" cylinder has good compression by performing an engine compression test.
- The cylinder compression test is another important test, since these are high mileage vehicles. Here's the test explained in detail:
- Test fuel injector activation signal:
- Use a Noid light to check if the fuel injector is receiving its activation signal.
- This tutorial explains how to use a Noid Light:
- How To Use A Noid Light And Where To Buy It (at: easyautodiagnostics.com).
- Check the fuel injector's internal resistance:
- Verify the fuel injector's resistance is within specification.
- Check that the fuel injector sprays fuel:
- This test is a game-changer! It'll help you visually see if the fuel injector is actually spraying fuel. You can find this test in this section: Checking If The Fuel Injector Sprays Fuel.
- Swap the fuel injector (if you don't a fuel injector spray testing tool):
- If all previous tests indicate that the fuel injector is clogged, swap it with an adjacent one.
- If the cylinder failure follows the swap, then the fuel injector is likely clogged and needs cleaning or replacement.
The testing strategy is a step-by-step elimination process to identify the clogged fuel injector whereby Checking each component until you find the culprit is found of the cylinder misfire.
TEST 1: Checking The Resistance Of The Fuel Injectors
To get started, we'll measure the resistance of all four fuel injectors using a multimeter set to Ohms mode. This test will help us determine if a fuel injector has an internal electrical issue.
According to the Toyota repair manual, the standard internal resistance for a fuel injector (1992-1996 2.2L Camry) is around 13.8 Ohms.
What we want to do is identify any injector whose resistance differs noticeably from the others. If an injector has an internal circuit fault, you'll typically observe one of these scenarios:
- Short-circuit problem: The resistance reads 1 Ohm or less, suggesting a short-circuit issue in the fuel injector's winding.
- Open-circuit problem: The resistance is in the thousands (K) of Ohms, indicating an open-circuit in the injector's winding.
- Deviation from standard: The resistance deviates by 10 Ohms or more from the standard value.
Let's get started:
- 1
Disconnect the fuel injectors from their electrical connectors.
NOTE: This test is done with the engine OFF. - 2
Set the multimeter to Ohms (Ω) mode.
- 3
Measure the fuel injector's resistance across its two male terminals with the multimeter probes (see the illustration above).
- 4
Record the resistance value that your multimeter shows for the specific fuel injector you're testing.
NOTE: Cylinder #1 is the one closest to the drive belt. Cylinder #4 is the one closest to the transmission. - 5
Repeat steps 1 to 3 for the remaining fuel injectors.
Let's interpret your test results:
CASE 1: All four injectors show similar resistance values. This is the correct test result and tells you none have a short-circuit or open-circuit issue.
Keep in mind, a resistance test won't detect a clogged injector. The next step is to remove the "dead" cylinder's fuel injector and check that it's spraying fuel. Go to: Checking If The Fuel Injector Sprays Fuel.
CASE 2: One injector's resistance significantly deviates (by 10 Ohms or more) from the others. This tells you that the fuel injector is bad. Replace the fuel injector.