[sureshshanmugam]

Hi,

I am trying to understand a few things on fuel injector. Would be great if some mate can throw some light on the felow questions.

1. What is a Fuel Injector, how is it different from the operations of a carbeurator?
2. How often do we need to clean the fuel injector?
3. What is the procedure to clean an injecotr?
4. Are there any injector cleaning liquids that will do this job?

Thanks in advance.

[sgiitk]

Originally Posted by sureshshanmugam

1. What is a Fuel Injector, how is it different from the operations of a carbeurator?

I am talking purely in the context of a petrol engine. In a carb air as it goes in sucks in petrol. In an injector air control is different, and the petrol is injected (controlled by the ECU) in the manifold in the middle (Single point FI, now obsolete), just outside the inlet valve (MPFI - the most common), or directly in the cylinder (Direct FI). The control on the fuel is far more precise resulting in more power, better economy and lower emissions.

Originally Posted by sureshshanmugam

2. How often do we need to clean the fuel injector?

Depends. You may need to do so may be once a year or two in our conditions. If you use 'bad' fuel then you may need it more often.

Originally Posted by sureshshanmugam

3. What is the procedure to clean an injecotr?

Essentially force a solvent through the injector nozzle. This is what the cleaning machines do.

Originally Posted by sureshshanmugam

4. Are there any injector cleaning liquids that will do this job?

There are fuel additives which help degunk the injector system. They work only in very low levels of contamination.

[dadu]

Originally Posted by sureshshanmugam

Hi,

I am trying to understand a few things on fuel injector. Would be great if some mate can throw some light on the felow questions.

1. What is a Fuel Injector, how is it different from the operations of a carbeurator?
2. How often do we need to clean the fuel injector?
3. What is the procedure to clean an injecotr?
4. Are there any injector cleaning liquids that will do this job?

Thanks in advance.

Injectors can be of many types but their working meachnism is the same, see picture below. In a Carburetor fuel delivery is not controlled its forced using a fuel pump and mixed with air for the engine to burn.



In an injector the delivery of fuel can be controlled using the pintle inside it. If required I can post a sectional diagram for better understanding.


Deposits at 2500 KM and then cleaned injector

Deposits that form on the injector nozzle can cause incorrect spray and atomization, but I would say you do not need to clean it regularly unless you have some problem symptoms or loss of fuel efficiency. As you see deposits start forming as we run the engine.

Again injectors can be cleaned manually by removing and putting them through cleaner machines using special liquid or by using fuel additives or by ultrasonic cleaning. Fuel additives being the easiest but not the most effective way.

I would say, always try mild additives before moving onto strong ones, SystemD/ G works good with most of us, otherwise move on to BG products, they are good.

[dhanushs]

Originally Posted by sureshshanmugam

1. What is a Fuel Injector, how is it different from the operations of a carbeurator?

You might wanna check out this link. Carburetor vs Fuel Injection

A simple yet detailed/useful explanation about how a carb differs from FI.

Originally Posted by sureshshanmugam

2. How often do we need to clean the fuel injector?

I guess modern day engines with fuel injectors are quite efficient from keeping away dirt from the injectors(I think fuel adulteration has decreased) and you will have to manually clean them only when necessary. ie when your car starts showing symptoms of power loss etc.. Otherwise using a good fuel additive should do the job.

Originally Posted by sureshshanmugam

3. What is the procedure to clean an injecotr?

4. Are there any injector cleaning liquids that will do this job?

This link may help.
Troubleshooting & Cleaning Dirty Fuel Injections

[pranavt]

Does anyone in India have proper machines to do flowtesting and cleaning of injectors? Wish to flowtest my injectors before putting them in my car.

[sgiitk]

I think most of the better garages have them. Check for volume in a certain number of cycles. State of repair of the units is a big ?

[dadu]

Originally Posted by pranavt

Does anyone in India have proper machines to do flowtesting and cleaning of injectors? Wish to flowtest my injectors before putting them in my car.

Most A.S.S will have the apparatus but I am not sure if they know how to operate it properly and measure the flow and spray etc.

I have myself seen it in Hyundai, they remove the injector, place it in the apparatus, fill the liquid, start it. Do this once more and you are through.

Nobody bothers to put attention to the Spray pattern and/or the flow.

[pranavt]

It is the flowtesting part that is important as it could be dangerous for the engine to have a even a single cylinder running leaner than usual and it wouldn't show up nicely on the wideband. Will try and check out a few service centres around Mumbai. Might as well just get them flowtested in the US before they leave for Indian shores. Witchhunter in the US does it for 19USD per injector (cleaning & flowtesting) which is reasonable for the amount of attention they give to them (http://www.witchhunter.com/process2.php4).

[pramodkumar]

I have not found a single mitsu A S S have an injecter cleaning machine, of late my cars pull is not linear and usually during cold starts the car sputters, i suspect the injectors to be the culprit but, The A S S i give my car to has no idea how to clean them. I guess some DIY steps posted here might help. Some one please do the needful.


Pramod

[pranavt]

Cleaning injectors is one of the things I wouldn't want to do myself, even after having done extensive mods around and inside the engine myself without anyone's help. The usual DIY steps are useless beyond a certain point and you can never really check for linear/equal flow between injectors without a proper flowtesting machine. Inequal flow between injectors causes loss of power and can cause bigger problems if any of the injectors are not flowing properly.

[pramodkumar]

Originally Posted by pranavt

Cleaning injectors is one of the things I wouldn't want to do myself, even after having done extensive mods around and inside the engine myself without anyone's help. The usual DIY steps are useless beyond a certain point and you can never really check for linear/equal flow between injectors without a proper flowtesting machine. Inequal flow between injectors causes loss of power and can cause bigger problems if any of the injectors are not flowing properly.

got your point, but i remember some one doing it DIY on his versa, thought it would be easy, was not ablt to find the link to that thread.

Pramod

[dadu]

The only DIY you can do is add the additive to your tank.

[pramodkumar]

Originally Posted by dadu

The only DIY you can do is add the additive to your tank.

Done that already, used system G for a very long time


Pramod