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Ron Ananian, The Car Doctor - October 11, 2025 - Hour 1 - Diagnosing Fuel Injector Faults - (855)560-9900 24/7 Hotline

Ron Ananian, The Car Doctor - October 11, 2025 - Hour 1 - Diagnosing Fuel Injector Faults - (855)560-9900 24/7 Hotline

Ron Ananian The Car Doctor Oct 11, 2025 33 min
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About this episode

Ron Ananian dives deep into diagnosing fuel injector faults, specifically focusing on the P0203 code, which indicates an injector circuit fault. He shares a real-life case involving a 2015 Jeep Wrangler experiencing misfires and discusses the importance of testing the entire injector circuit. Listeners will learn about common misconceptions regarding misfires and the significance of proper diagnostics. The episode also touches on winter driving preparedness and features engaging listener calls about classic cars and electrical issues, providing practical advice and insights from Ron's extensive experience.

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Technical Too Afraid to Ask
Term

P0203

"I want to talk about P0203. P0203 is a fault code."

P0203 is a code that mechanics use to identify problems with the fuel injector for the third cylinder in an engine. If this code appears, it usually means there might be an issue with how fuel is being delivered to that part of the engine.

Car

Jeep Wrangler

"We had a 2015 Jeep Wrangler, V6 to 3.6, came into the shop this week..."

The Jeep Wrangler is a tough, off-road vehicle that can handle rough terrain. The 2015 version has a V6 engine, which gives it good power for driving in challenging conditions.

Term

cylinder misfire

"It's reported P0303, cylinder misfire, P0203, injector circuit fault."

A cylinder misfire happens when a part of the engine doesn't work right, causing the engine to run unevenly and lose power. This can be due to problems with spark plugs or fuel delivery.

Term

injector circuit fault

"P0303, cylinder misfire, P0203, injector circuit fault."

An injector circuit fault means there's a problem with the part that controls how fuel gets into the engine. If this isn't working, the engine might not run well.

Term

check engine light

"and the check engine light comes on and the light starts to flash,"

The check engine light is a light on your dashboard that tells you something might be wrong with your car's engine. If it comes on, it's a good idea to get it checked out.

Term

spark plug

"it needs a spark plug, right?"

A spark plug is a part of your car's engine that helps start the engine by creating a small spark. If it’s not working well, your car can have trouble running smoothly.

Part

injector connector

"And it was a simple process to get to the injector connector, unplug it, and we read about 14 ohms of resistance."

An injector connector is a part that connects to the fuel injector, helping it get the electrical signals it needs to spray fuel into the engine.

Term

ohms

"...we read about 14 ohms of resistance. Well, the circuit, and I know this just from having done these before..."

Ohms measure how much resistance there is to electricity. In cars, this helps check if parts like fuel injectors are working correctly.

Term

resistance

"...the circuit, and I know this just from having done these before, those injectors typically read between 10, 10 and 16 ohms of resistance."

Resistance is how much a part opposes the flow of electricity. It's important for checking if electrical parts in cars are working properly.

Term

ASD relay

"you have to pull out the ASD relay, the automatic shutdown relay. And I checked the circuit live."

The ASD relay is a part of the car's electrical system that turns off the fuel and ignition if something goes wrong. This helps keep the engine safe from damage.

Term

PCM

"...termination at the PCM out to the injector to make sure that it read the same and it did."

The PCM is like the brain of the car that controls how the engine and transmission work together. It helps the car run smoothly by making adjustments based on information it receives from sensors.

Term

P0201

"My problem now, I set a P0201 diagnosis confirmed. I've got a bad injector that measured correctly as far as resistance..."

P0201 is a code that tells you there's a problem with the fuel injector for the first cylinder in the engine. It helps mechanics figure out what's wrong.

Term

wiring harness

"...especially on the Jeeps where the wiring harness runs up and around the intake plenum is, we're looking for critters, right?"

A wiring harness is like a network of wires that connects different parts of a car, allowing them to communicate and work together. If it's damaged, it can cause electrical problems.

Part

injectors

"Put a set of injectors in it, all right? At my suggestion, the customer agreed, higher mileage, older vehicle."

Injectors are parts of a car's engine that spray fuel into the engine to help it run. If they get old or damaged, the car might not work as well.

Car

Chevy II Nova

"...how can I help? 1967 Chevy II Nova,"

The Chevy II Nova is a small car made by Chevrolet that was popular in the 1960s. The 1967 version is known for being affordable and easy to maintain, making it a favorite among car lovers.

Car

Chevrolet Chevy II

"All right, how can I help? 1967 Chevy II Nova, been decoding the Protector plate"

The Chevy II, or Nova, is a small car that was made in the 1960s and is loved for its simple design and good performance. The 1967 model is especially popular among people who like classic cars because it looks cool and has a lot of power.

Term

Protector plate

"The Protector plate, the engine code on the Protector plate is ZI, and I traced that back to being a L79."

A Protector plate is a small metal tag on a car that shows details like the engine type. It's used to check if the car's parts are original and correct.

Term

L79

"...I traced that back to being a L79. But then, like I said, the window sticker..."

The L79 is a powerful engine that was used in some older Chevrolet cars. It's popular among car fans because it offers good performance.

Term

CE block

"The 327, this is where the twist is, it's got a CE block in it, and it's got L79 pistons in it, because I put a camera in there and looked at the, the number on top of the piston..."

A CE block is a type of engine block used in some Chevrolet cars. It helps identify what kind of engine it is and what parts can be used with it.

Term

casting number

"...because I put a camera in there and looked at the, the number on top of the piston, and it's 3866954."

A casting number is a special code found on engine parts that helps identify what the part is and its specifications. It's like a name tag for engine components.

Term

horsepower

"to ruin an engine in one of those because of the horsepower they put out. So, I think it really comes back to..."

Horsepower is a way to measure how powerful an engine is. The more horsepower an engine has, the faster and stronger it can make a car go.

Car

Chevrolet Chevelle

"...but he had a 65 Chevelle SS 396 car. By the time he got it in the early 70s,..."

The Chevelle SS 396 is a classic American muscle car from 1965. It was known for its strong engine and sporty design, making it popular among car enthusiasts.

Term

big block

"it had a 283 in it because the original big block was gone."

A big block is a type of car engine that is larger and usually provides more power than smaller engines. It's often found in muscle cars and performance vehicles.

Concept

automotive history

"...But that was a piece of automotive history. I think those were the cars the first year 65..."

Automotive history is the story of how cars have been made and changed over the years. It includes important cars and inventions that have influenced how we drive today.

Term

older cars

"...the problem with all the older cars, it's not that they won't go the distance, but if they break, you can't buy parts..."

Older cars are vehicles that were made a long time ago. They might not work as well for long trips because they can break down more easily and finding parts to fix them can be hard.

Car

Chevrolet Monte Carlo

"I went to college in a 72 Monte Carlo And, you know, I broke down on the side of the Garden State Parkway."

The Chevrolet Monte Carlo is a type of car made by Chevrolet, popular in the 1970s. The 1972 version is known for being stylish and having good performance.

Term

327

"I think it was a 327 350 horse car. And it was very rare and very, very much sought after then as it is today."

The '327' is a type of engine size used in some classic cars, especially Chevrolets. It's known for being powerful and is often sought after by car enthusiasts.

Part

voltage regulator

"...so I don't know what the voltage regulator is at. Well, the voltage regulator is built into the alternator."

The voltage regulator is a part that helps control the amount of electricity that goes to the battery and other electrical parts of the car, making sure they get the right amount of power.

Car

Ford Escape

".... Tell me your story. Okay, so I got a 2009 Ford Escape. About six months ago,"

The Ford Escape is a small SUV that is great for driving around town or taking on trips. The 2009 version is known for being comfortable and having enough space for passengers and luggage, plus it even has a version that saves on gas.

Term

OBD2

"Now I'm not talking about something OBD2, do you have something that'll go year make model?"

OBD2 is a system in cars that helps check if everything is working properly. It can tell mechanics if there are any problems with the engine or other important parts.

Term

voltmeter

"...I'd put a voltmeter on it. Okay. Because I just want to know, do I have signal?"

A voltmeter is a device that checks how much electricity is flowing through a wire. It's useful for figuring out if there's a problem with the car's electrical system.

6 cars featured

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