Should anything be done to fuel injectors that have been dormant before using them again?

 

It would be a good idea to get them cleaned and tested unless they are basically brand new except for the engine swap time.

 

Don,

Did you get the emails??
I'll be sending some out to RC in 11 days.

 

Well, they were cleaned then used for a few hundred miles and then removed. Not sure how long they've been dormant but I doubt they need cleaning. If anything, a good lube job to make sure they are not stuck... but I'm not sure what to use or how to do it, or even if that should be done.

 

Anyone?

 

Kinda wondering the same thing...

 

I think you can just hook up a 12v source to them and you should be able to hear them click, and if it a weird kinda cluckish sound they are not working right. If you put them in the car I would probably just run some good injector cleaner through the first tank of gas, that should help.

 

I agree with Chris.. Hook it up to some 12V and listen to the clicking.. No clicks.. its stuck!

 

Before doing any of that I would call witchhunter or RC and ask them. Why risk hurting one of them when you can go straight to the horses mouth. Just my opinion.

 

I just talked to RC Engineering, they said that hitting the injector with 12v would work fine to test them. If they don't click, I'm not sure what you can do besides sending them back out to be cleaned again, maybe a gasoline bath?

Jason

 

You can test your injectors with a little alteration to your rail setup, no smoking and use at your own risk. Remove the rail and replace the short fuel lines temporarily with two longer (about a foot, or foot and a half) injection rated hose, so that you may suspend the injectors above a container to catch fuel.

Very carefully apply 12v across the injector lead being careful not to short the current and produce an arc, I don't recommend bare wiring this, would suggest using leads with insulated covers.

Now if you could put a timer on it you could do a volume test, but at this point you can test leakage and observe a spray pattern.

 

I've done what danny has described, but for safety I connected a battery using the lead(s) at the ECU and the ground at the main relay. So my connections were several feet from a the gas fumes.

Part of the problem is that injectors that click may still stick at high duty cycles or leak a little because they don't seal off completely. I'm not sure there is anything that can be done to prevent this, but installing them ASAP after the ultrasonic cleaning is a great first step. In my case, all 4 passed this 12v '**** test' but wouldn't run properly at more than mid throttle.

Dave

 

I'm a hack with electricity but, if you are applying 12v directly, are you at 100% duty?

 

I believe so. They just clicked open and shot a stream of fuel. I tapped it off and on and it seemed to be 100% responsive.

In any case, my car ran like garbage on those injectors until they were cleaned by Witchunter. My first cleaning was done by a local dirt oval racing shop, who had the cleaner buy couldn't test the results. Injectors are cheap to ship quickly - I wouldn't cheap out on it again.

Dave

 

Fuel injection 101:
1. A fuel injector is nothing more than a solenoid.
2. A fuel injector is alway operating at 12v.
3. In a 4 stroke engine (intake, compression, combustion, exhaust). % duty cycle = (injector opening duration / max intake cycle duration) * 100. For example, if you max intake cycle duration is 100 ms and the injector is open for 50 ms, the duty cycle would be (50/100)*100 = 50% duty cycle.

 

If what you saw was a tream of fuel than you do in fact have a clogged injector. An injector in good working condition should produce a nicely atomized (fine mist) circular spray pattern.

 

so, in the test setup one is at 100% duty. I last did it while replacing either the dampner or FPR, only had about 7000m since recalibration. was under the rat's nest so not much more to do to check it out. would be nice to add a 10 second shut off timer switch, at least one could get volume.

 

As I wrote that the same thought went thru my head, but I'm not sure why it would make a stream. Is it shooting a stream because the clog had slowed the flow down?

Dave

 

Well, my fuel injectors are not installed (hell, the engine is not even installed for that matter), so how could I test them? So if they've been cleaned and used before, do they need to be soaked or lubed before reinstalling?

 

Same as described earlier. Just touch them to a 12v source and listen for them clicking on/off.

I don't believe so. The problem with them sitting for a while is usually after they are cleaned because of the solvents used. From what I gather in your thread, you had them running and pulled them out. So the last thing through them was gasoline. If that's the case, they should be fine as long as they pass the "click" test above.

 

Well, they pass the "click" test. Now, is there anyway to test the flow/spray pattern out of the car? I have nothing installed (no fuel pump, no hoses, no lines, etc.), so I can't hook them up to the car's system.

 

As far as I know, that's about all you can test. The rest of the stuff is usually left up to the big guys like RC Engineering and WitchDoctor.

 

LOL, I think that's Witchhunter

 

I like Doctor better.