The Infiniti G35 is a beast on the road, but its engine is picky about fuel. When a fuel injector fails, the car lets you know. You might notice a rough idle or poor gas mileage. I will show you how to spot these problems before they leave you stranded on the highway.
You must act fast if your engine feels sluggish or shakes at stoplights. Listen for clicking sounds from the engine bay, and check your dashboard for a flashing check engine light. Scan the computer for codes, then perform a balance test to pinpoint the exact cylinder that is failing to fire correctly.
Understanding Your G35 Fuel System
The G35 uses a complex fuel delivery system to keep the V6 engine happy. Injectors spray gas into the cylinders. When they get dirty or break, the air-fuel mix fails. This ruins your performance. Here are the main things to watch, as these parts eventually wear out after many miles of hard driving.
Clogged Fuel Injector Nozzles
Tiny holes in the injector nozzles get blocked by carbon deposits. The fuel cannot spray in a fine mist, so the engine starves. Your car will feel weak, and it will struggle to climb hills. You might also notice a smell of raw gas, as the fuel just sits there inside.
Leaky Fuel Injector Seals
Rubber O-rings keep the fuel inside the rail. These rings get hard and crack over time. A leak here is dangerous, as fuel could drop onto the hot engine. If you smell gas near the engine cover, check these seals. Replace them right away, because a fire is a real risk.
Electrical Solenoid Failure
The injector is a tiny valve run by electricity. If the coil inside dies, the valve will not open. You will get a dead cylinder. The car will shake, and the exhaust will pop. It feels like a bad spark plug, but the problem is actually the fuel not getting in.
Fuel Pressure Regulator Issues
The regulator keeps the fuel flow steady. If it fails, the injectors get too much pressure or not enough. The car will surge, and you will see weird gas mileage numbers. This part works with the injectors, so do not ignore it when you look for the cause of your car problems.
Dirty Fuel Filter Blockages
A bad filter lets trash reach the injectors. The screen inside the injector gets clogged fast. This prevents the spray from working, which kills your engine power. Change your filter every few years, as this saves your expensive injectors from getting ruined by the junk floating inside your gas tank.
Carbon Deposit Build Up
Old gas leaves gunk on the valve tips. This build up messes with the spray pattern. Your car will have a rough idle at stoplights, and it will stumble when you hit the gas. Use a high-quality cleaner in your tank, but replace the injectors if the gunk is too thick.
If you suspect an injector, do not drive the car for long. You could wash the oil off your cylinder walls. This causes deep scratches, which ruins the engine for good.
- Check for misfire codes.
- Listen for ticking sounds.
- Test the fuel pressure.
- Inspect the rubber seals.
- Use a scanner tool.
- Replace damaged injector units.
✅ Also Read: Kia Soul Clogged Fuel Filter (Don’t Ignore)
How to Fix a G35 Bad Fuel Injector
Fixing these parts is not a walk in the park. You need patience to pull the intake manifold. Do not rush, as small parts get lost easily. I have done this job many times, and it is a great way to save money if you are willing to get your hands dirty.
Tools for the Job
You need a socket set and a torque wrench. Get a new set of O-rings, as you should never reuse old ones. A good flashlight helps you see in the tight spots. You also need a fuel pressure gauge to check the line, because you want to be sure about the pressure.
Preparation is the secret. Clean the area around the injectors before you pull them out. Dirt is the enemy. It falls into the cylinders, and that causes massive damage to the engine walls. Use a shop vac to clear away debris, then take your time to remove the bolts.
Finally, keep track of all the vacuum lines you disconnect. Take a photo of the engine bay before you start. This helps when you put it back together, as those hoses get confusing quickly. If you forget where they go, the car will run bad or not start at all.
Safety During Fuel Work
Fuel lines are under high pressure. Wrap a rag around the connection before you crack it loose. This catches the spray. Keep a fire extinguisher close, because gas fumes are everywhere. Never smoke or have an open flame nearby, as that is a recipe for a bad day at home.
Work in a well-ventilated area. If you are in a garage, open the door wide. Breathing in gas fumes gives you a headache, and it is not good for your health. Wear gloves, as the gas will dry out your skin, and you want to stay clean while working.
Take your time with the fittings. Do not force anything. If a bolt feels tight, use a bit of oil. You do not want to snap a stud, as that turns a one-day repair into a long nightmare. Patience is your best friend when working on a car.
Injector Rail Removal
The fuel rail sits on top of the injectors. Remove the bolts holding it down. Gently wiggle the rail to break the seal. Do not pull too hard, as the injectors might stay stuck in the engine. Pull them out with the rail, but be careful not to bend the metal lines.
Once the rail is off, remove the old injectors. Check the bores in the engine for trash. Use a clean rag to wipe out the holes. If you see any rust or deep gouges, you might have a bigger problem. Put the new injectors in, but remember to lube the O-rings.
Use clean engine oil on the rubber seals. This helps them slide into the engine without tearing. If you tear a seal, it will leak fuel. That is a dangerous mistake. Press them in until you feel a soft pop, which means they are seated in the right spot.
Electrical Connections
Each injector has a plug. Push it on until it clicks. If the clip is broken, use a zip tie. You need a solid connection, or the car will misfire. Check all the wires for cracks, as the heat from the engine makes them brittle and prone to failing at bad times.
Look at the wire harness carefully. Are the wires pinched? Is the plastic melted? Repair any bad spots with heat shrink tubing. Do not use cheap electrical tape, because it will just fall off in the heat. Do it right once, and you will not have to worry about it again.
Make sure the wires are tucked away from the hot exhaust manifold. Heat ruins insulation fast. Use zip ties to keep the harness neat and clear of hot parts. This prevents shorts, which can kill your computer and leave you with a car that will not start at all.
Checking for Leaks
Turn the key to the ‘on’ position but do not start the engine. The fuel pump will build pressure. Look at the injectors. Use your flashlight to check for wet spots. If you see fuel, turn the key off immediately. You have a bad seal, and you must fix it now.
Do not start the engine until you are sure the system is dry. If you see a leak, pull the rail again. Check the O-rings for damage. It is better to spend another hour fixing a seal than to burn your car to the ground. Trust me on this.
Once everything is dry, start the engine. Let it run for a few minutes. Check the fuel rail one last time. If it stays dry, you did a great job. Go for a test drive, and watch for that check engine light to go away for good.
Final Assembly
Put the intake manifold back on. Torque the bolts to the factory spec. Do not overtighten them, as you could crack the plastic. Check all the vacuum hoses one more time. Make sure every single clip is locked in place. A loose hose creates a vacuum leak, which ruins your idle.
Put the engine cover back on. It keeps the bay looking clean. Start the engine, and listen to it purr. It should be smooth and quiet. If it still shakes, you might have an ignored the warning light for days issue. Take it to a shop to run a deeper diagnostic scan.
Take the car for a long drive. Let the computer learn the new parts. If the light comes back, pull the codes again. You might have a bad spark plug or a coil pack. Keep a log of what you changed, as this helps you track the history of engine repairs.
Replacing these parts is hard work. If you follow the manual, you will save a lot of cash. Keep your tools clean, and never rush the job. You will be back on the road in no time with a car that runs like it just came off the lot.
- Relieve fuel pressure first.
- Clean the engine area.
- Lubricate every O-ring.
- Verify the electrical plugs.
- Check for fuel leaks.
- Test drive the vehicle.
Can a Bad Injector Kill My Engine?
Yes, a faulty injector can ruin your engine fast. When an injector stays stuck open, it dumps too much fuel into the cylinder. This liquid gas washes the protective oil off the cylinder walls. Without oil, the piston rubs against the metal, and this creates deep scores that wreck your engine compression.
You also risk a hydrolock if the cylinder fills with gas while the car sits. When you try to start the engine, the piston cannot move up. This snaps a connecting rod. A badly leaking fuel injector is a ticking time bomb for your motor, so never delay the repair.
If you notice a sudden drop in fuel economy, your injectors might be failing. The engine computer tries to compensate for the bad spray, but it cannot fix a physical part that is stuck. You will burn more gas, and your spark plugs will foul out with black soot very quickly.
Always check your oil level if you suspect an injector problem. If the oil level is rising or smells like gas, stop driving. The fuel is leaking past the rings into the crankcase. This thins your oil, which destroys the bearings in your engine. Change the oil and the injectors immediately.
- Monitor the oil level.
- Check for gas smells.
- Watch for black smoke.
- Scan for misfire codes.
- Listen for engine noise.
- Stop driving if shaking.
How Do I Know If the Injector is Truly Dead?
You can test them with a basic multimeter. Unplug the injector, and measure the resistance across the two pins. Compare the reading to the factory manual for your G35. If the reading is way off or zero, the coil is dead and you need to buy a brand new part.
Another way is the screwdriver trick. Put a long screwdriver against the body of the injector. Hold your ear to the handle while the engine idles. You should hear a steady clicking sound. If one injector is silent while others click, it is likely stuck or has a bad electrical connection.
Don’t forget to check the wiring harness. A damaged fuel injector connector can look just like a bad part. Wiggle the wires while the engine runs. If the engine idle changes, you found a bad wire. Fix the connector or replace the plug to restore the power to the injector.
If the engine is still acting up, it might be the clogged fuel injector screen. Sometimes the part is fine, but the filter inside is blocked with debris. You can try a professional cleaning service, but replacing the unit is often cheaper and faster for a car as old as the G35.
- Measure coil resistance.
- Listen for ticking sounds.
- Inspect electrical plugs.
- Check for wire breaks.
- Use a scanner tool.
- Test with a stethoscope.
Will a Fuel Injector Cleaner Help My Car?
A bottle of cleaner helps if your injectors are just dirty. If they are broken, no amount of fluid will fix them. Pour the cleaner into a nearly empty tank, then fill it up with premium gas. This mixes the chemicals well and lets them work on the internal parts of the injector.
Drive the car on the highway for a few miles after adding the cleaner. The higher speed and engine load push the cleaning agents through the system. This is much better than just idling in your driveway. You might notice the engine runs smoother after the tank is almost finished.
Do not use cheap cleaners too often, as they can sometimes damage old rubber seals. Stick to quality brands that are safe for your specific fuel system. If you see no improvement after two tanks, you are wasting your money. Move on to a mechanical test to find the real problem.
If you have a failed fuel injector solenoid, the cleaner will do nothing. You have an electrical fault, and that requires a new part. Don’t be fooled by ads that promise to fix everything. Some parts just wear out, and they need to be replaced by a human mechanic like you.
- Use high quality cleaner.
- Add to low tank.
- Drive at highway speeds.
- Check for smoother idle.
- Repeat for two tanks.
- Replace if no change.
Can I Replace Just One Fuel Injector?
You can replace just one, but I suggest doing the whole bank. If one failed, the others are likely close to the end of their life too. You don’t want to pull the manifold again in two weeks. It is better to spend the money now to save your weekend later.
If you choose to replace just one, make sure the new part matches the flow rate of the old ones. Mixing different types of injectors makes the engine run lean on one side. This causes the computer to get confused, and your check engine light will stay on forever.
Make sure you get high quality parts. Cheap injectors from online stores are often junk. They might leak or have the wrong spray pattern. Always buy from a trusted brand, because you don’t want to redo this job. Your time is worth more than the few dollars you save on cheap parts.
If you do replace just one, keep the old ones as spares if they still work. You never know when you might need them. Label them by cylinder number, so you remember which one was which. This keeps your shop organized and makes the next repair much easier to handle for you.
- Match the flow rate.
- Buy from trusted brands.
- Replace the whole bank.
- Use new O-rings.
- Test the electrical plug.
- Reset the engine computer.
Final Thoughts
I hope this guide gives you the confidence to tackle your G35 fuel injector issues. It is a tough job, but you can do it. Take your time, stay organized, and keep your workspace clean. You will save a ton of money and learn how your car really works. If you get stuck, take a break and come back later. Good luck with your repair.
| Symptom | Cause | Solution |
|---|---|---|
| Rough Idle | Dirty Nozzle | Use Fuel Cleaner |
| Gas Smell | Leaking O-ring | Replace Seals |
| Engine Misfire | Dead Solenoid | Replace Injector |
| Power Loss | Clogged Filter | Replace Filter |
| P0300 Code | Bad Spray | Test Injectors |
| High Gas Use | Stuck Open | Swap Injector |
| Car Shaking | Bad Cylinder | Balance Test |
| Hard Starting | Low Pressure | Check Regulator |
| Pop in Exhaust | Fuel Mix Off | Inspect Rail |
| Engine Light | Faulty Part | Scan Codes |
Frequently Asked Questions
Is a Bad Fuel Injector Dangerous?
Yes, a leaking injector creates a fire risk because fuel drips onto hot engine parts. It also washes oil off cylinder walls, which causes internal engine damage that leads to complete failure over time. You should stop driving the vehicle and fix the problem as soon as you detect a gas leak.
Can I Drive with a Bad Fuel Injector?
You should not drive with a bad injector because it causes engine misfires and poor performance. The unburned fuel enters the exhaust and destroys your catalytic converter. This turns a cheap injector repair into a very expensive exhaust system replacement that you really want to avoid in your G35.
Are G35 Fuel Injectors Hard to Change?
The injectors are buried under the intake manifold, which makes them hard to reach for a beginner. You need to remove several parts and follow specific steps to avoid leaks or vacuum issues. It is a time-consuming project, but you can finish it if you stay patient and follow instructions.
Do I Need Special Tools for This Job?
You need a basic socket set, a torque wrench, and a fuel pressure gauge to do the job right. Having a scanner tool is also helpful to read error codes from the computer. None of these are rare, but you should have them ready before you start pulling the engine apart.
Will the Check Engine Light Turn Off?
The light usually clears itself after you replace the bad part and drive the car for a while. If it stays on, you might have another problem like a bad spark plug or a vacuum leak. You can use a scanner to clear the code manually after the repair is done.
Should I Replace All Injectors at Once?
Replacing all injectors at once is the best way to ensure the engine runs smooth. Since they all have the same amount of miles, the others will likely fail soon after the first one dies. Doing the job once saves you from tearing the engine down multiple times in one year.
Will Bad Injectors Cause a Start Failure?
A bad injector can cause a hard start or no start at all if it leaks fuel into the cylinder while the car is parked. This floods the engine with gas, making it impossible for the spark plug to ignite the mix. You might smell raw gas when this happens.
Does a Noisy Injector Mean It is Broken?
A faint clicking sound is normal, but a loud tapping or silence can mean the injector is failing. Compare the sound to the other injectors using a long screwdriver as a listener. If one sounds different than the rest, that is a sign that something is wrong with that unit.
