How to Repair a Cracked Fuel Injector

What You'll Need
Masking tape and marker
Welding equipment
Pressurized hose
Injector cleaning machine
Protective eye goggles

A cracked fuel injector can be the reason for an array of troubles that you encounter with your car’s engine. To get the maximum fuel efficiency from your car, you must have a well functioning fuel injector. Over time, a cracked fuel injector may lead to different problems, including a fuel leak. A leaky injector will decrease a car’s gas mileage, so you will end up paying more for gas. A bad fuel injector restricts the flow of fuel into the engine cylinder, which will greatly decrease the force of combustion which will later cause either a coarse engine idle or misfiring. For all this reason, repairing a cracked fuel injector is an auto repair you should learn to do on your own.

Step 1 - Disconnect Battery

For safety purposes, disconnect the battery using a wrench.

Step 2 - Disassemble

Disassemble the injectors, not only the one with the crack but all of them. Then depressurize the fuel scheme by holding a rag on the pressure fitting and push it. The throttle cable and the cruise control assembly should be removed, as will the three bolts holding it in place. Each connector from the injectors should be numbered (use the masking tape and marker) according to how they were removed because they have to go back in the same place.

Step 3 - Inspect

Loosen the cable on the car battery

Inspect the fuel injector parts. The repair of each part will be different from the repair of another. Therefore, you must know which part is damaged so that you will know what to do. Also, take note of the degree of damage for you to be able to decide if the fuel injector is worth the cost of repair, or if buying a new injector is more sensible.

Step 4 - Determine Scope of Problem

If the crack is on the housing then all you have to do is to weld the cracks. When welding the cracks make sure that you will end up with a smooth patch. If the crack is on the gear, you must replace the defective gear. You do not have to replace the entire injection pump. Be sure to wear protective eye goggles when welding.

Step 5 - Repair Cracks

After making sure that all cracks are patched, you can reinstall your fuel injectors. You must remember to lube the o-ring and then install it on each injector. You can use a small dish of clean motor oil to lube. Each numbered connector should be replaced on the proper injector making sure that the injectors are inserted in the right direction.

Step 6 - Clean Injectors

a row of fuel injectors

Clean your fuel injectors. If your injectors are not that dirty then you can clean it in place with a pressurized hose. If you have been using your fuel injectors for quite some time, then you have to remove them and use an injector cleaning machine. You must clean your injectors every 20,000 to 25,000 miles to maintain their efficiency. The payback for cleaning your injectors regularly is having a well functioning engine and not having to spend more for a more thorough cleaning if the dirt condition of your injectors becomes worse.

Step 7 - Test

If the above steps do not work, consider getting a new fuel injector. If you had been using your fuel injectors for quite a long time and if it had already been repaired more than twice then it is more cost effective to buy a new one than to spend time and money again for its repair.