how to test 7.3 Powerstroke injectors

Do you know how many fuel injector has on the 7.3 liter diesel engine? If your answer is no then I must tell you 8 engine remains on a 7.3 liter diesel engine. My next question is do you know How to test 7.3 powerstroke injectors? If your answer is no then I must tell you to read our below given steps to know How to Check the Injectors on a 7.3L diesel engine.

Do you know what can happen due to improper fuel distribution?

Improper fuel distribution can be the reason for loss of power, triggering of engine codes or mechanical failure. So it is important for you to test the 7.3 powerstroke injectors after driving your vehicle for certain kilometer so that you can identify the failure of fuel injectors in a early stage which will provide you prevention against costly repair which is associated with  too rich or too lean combustion conditions.

Read our similar article – Best 7.3 injectors

How to test 7.3 Powerstroke injectors

Today we are going to share with you the 5 different ways to test 7.3 powerstroke injectors. At first starting with how to test Injector Valve, Secondly we are are going to describe how to test the fuel injector wire voltage, Thirdly we are going to describe how to test the fuel injector resistance, Fourthly we are going to describe how to test fuel pressure regulator, fifthly we are going to describe how to test fuel injector leaks.

How to test Injector Valve

  • At first you should park your vehicle away from the crowd and after parking your vehicle you should not forget to push the hand brake before leaving your vehicle.
  • Now touch a tip of the long handled screwdriver to the top of the fuel injector. After that press the handle end of the screwdriver with your ear. You will hear a clicking sound which is produced from the operational fuel injector due to the engaging of solenoid and valve.
  • You must test wiring of a fuel injector which is not operational. If you find the wiring of a injector is functional then you must replace the fuel injector.

How to test the fuel injector wire voltage

  • At first you must turn the ignition key towards the on position. Starting the engine is not necessary. During the time of testing you can disconnect the electrical plug from the fuel injector.
  • Next you must set the multimeter into volts. After that you must insert the multimeter leads into each side of the injector plug. No particular polarity is required for doing the task. You should approximately keep 12 volts of voltage output on the multimeter.
  • You should replace the fuel injector if the engine control module is showing a sign of failure in the part, on the other hand lead is providing 12 volts. If the wire of the fuel injector is not producing 12 volts then immediately replace it.

How to test the fuel injector resistance

  • To test the fuel injector resistance you must set the multimeter to ohms. After that you should touch the red and black multimeter leads onto each side of the fuel injector plug terminals. What ever results you are getting you must keep a note on it.
  • Now you must take the similar reading from the remaining 7 injectors. After that compare the results of each injectors. While comparing you will notice that the reading of the injector are pretty similar for all fuel injectors. The failure injector will have totally different reading compared to normal injectors. You will notice that failure injectors are either displaying too much or too little resistance.
  • You must replace the injector immediately that is showing vast difference in reading.

How to test fuel pressure regulator

  • To test the fuel pressure regulator the first step that you should take is pull the vacuum line from the fuel pressure regulator.
  • Inspect the fuel pressure regulator. While inspecting the fuel pressure regulator you must look into the hole from which the vacuum line was pulled. If the fuel remains on it then you should understand that the diaphragm has been ruptured.
  • You must replace the fuel injector if the fuel remains on it. You must replace the vacuum hose if the fuel pressure regulator is operational.

How to test fuel injector leaks

  • To test the fuel injector leaks at first you should inspect the fuel injector connection to the fuel rail. If you watch that fuel is present then you must think that the fuel injector o ring has got damaged. This damaged or improperly seated fuel ring will leak fuel under pressure. The fuel lines are pressurized during operations.
  • So you just depressurize the fuel system and remove any bolt or on accessories that are air intake, tube, vacuum hoses or electronics, which hamper access to the fuel rail. Lastly you must lift the fuel rail off the fuel injector.
  • Remove the injector from the engine by just pulling the injector  directly out of the hole. Next you must replace the O rings on the fuel injector. Use small amount of motor oil on the O rings. Reinstall the fuel injector and fuel rail.

5 common symptoms of faulty diesel fuel injectors

Starting problem – If your diesel fuel injectors is faulty then it will create starting problem specially in cold weather. So if you face starting problem in your 7.3 diesel engine then check the fuel injector quickly.

Misfire – If your diesel engine starts misfiring then you should understand that its happening due to lack of fuel injection or a lack of combustion chamber heat.

Smell of fuel – If you are getting the smell of diesel from the vehicle’s cabin then you must understand the diesel has a leak somewhere which may be happening due to faulty injectors which allows fuel to flow out of the injector when it isn’t active.

Dirty smoke – Damage injectors can be the reason for incomplete fuel burn for which it releases white smoke from the exhaust pipe.

Poor mileage per gallon – We all know that faulty injectors burn more fuel compared to good fuel injector. So if you driven more than 100000 miles without changing your fuel injector then immediately change it to get better mileage per gallon.

how to test 7.3 Powerstroke injectors


So if you have read the above 5 different procedure of how to test 7.3 Powerstroke injectors then I think you do not need to take any one’s help for testing the 7.3 powerstroke injectors. You can do the task by yourselves only.

How do you tell if your 7.3 needs injectors?

If you find starting related problem, misfire, smell of fuel, dirty smoke or if you get poor mileage then you should understood that you need new 7.3 injectors.

What fails on a 7.3 injector?

The most common failure we see is when oil residue builds up inside the of the injector and causes the spool valve to move slowly or stick which is known as stiction. 

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top