Injector Click Test (outside of motor) Options

[JStroud]

Len, I just sent in 8 - 2.0 injectors for cleaning and flow testing, 4 are going in my car, the other 4, assuming they all work well, I was planning on putting up for sale.
Not sure what they're worth. But they're yours if you want them, make me a reasonable offer. Should get them back next week sometime.

Jeff

[lsintampa]

Len, I just sent in 8 - 2.0 injectors for cleaning and flow testing, 4 are going in my car, the other 4, assuming they all work well, I was planning on putting up for sale.
Not sure what they're worth. But they're yours if you want them, make me a reasonable offer. Should get them back next week sometime.

Jeff

Let me know when they come back - with luck you'll get 8 good working ones back.

Thanks,

Len

PS - The PO as I said claimed they were cleaned just prior to me getting the car. Turns out there were two sets of injectors - the other set (I think) may be the good set and that set is MIA - but there are three people trying to find them: me, the PO, and the shop that did the cleaning. So maybe, just maybe they may turn up. Wouldn't that be sweet?

[JStroud]

That would be sweet if you find them, good luck.
I'll let you know when I get mine back, all tested good with battery.

Jeff

[lsintampa]

I just went through this on a friends car that uses the same injectors. We cleaned them about 6 weeks ago in my ultrasonic cleaner and bagged them. Last week we went to fire up the motor and only had 2 working inectors. So I pulled the offending injectors and bench tested them just like you had done. No click, but passed electrical test. They were just stuck.

I simply banged them against the corner of my vise on the work bench a couple times and that was all it took. They began to click and the car was soon running on all 4 cylinders again. The moral of the story is this: If they don't work now, what's it gonna hurt them to get bashed a bit on the vise and see if that un-freezes them?? If they break,. . . well,. . . they're already broken so you have nothing to loose. (IMG:style_emoticons/default/smash.gif) (IMG:style_emoticons/default/biggrin.gif)

Ya know, I have said for years that the best tool I've ever purchased was my 3 pound sledge hammer. Would you know that soaking them in blaster overnight, then whacking the crap out of them on the sides, freed all four up. Now they click... of course I feel like I'm way ahead of the game, but who knows if I damaged them in the process?

Anyway, I also found out that if you hold them upside down (fuel supply nipple pointing down) and gently tap them on something solid - you dislodge any fluid and associated gunk and it comes out. When I did this to each injector, the stuff coming out was discolored (rusty looking) stuff. If I clicked an injector, then removed as much gunk by tapping upside down, the click would get louder and louder. So I did this until I couldn't get any more gunk out.

I'm taking them into the shop again for cleaning, screens - and hope they are good enough to run with.. at least for now.

(IMG:style_emoticons/default/w00t.gif)

[aircooledtechguy]

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[worn]

Have you licked that 9v battery lately? You sure it's good?

my thoughts exactly.

We have similar "valves" in my business.
Our systems usually "Hit" the valve with full bus voltage (in the case of our cars that is ~13 Volts running), to open it.
Then the voltage drops to just a few volts to hold it open for extended periods.

I would not be surprised if these systems hit the injector with 12V at the start of the "fire" then backed it down to 3V for the duration.

I cannot see any captured waveforms of our injector pulses with an oscope online to be sure.

The rated coil resistance of these is 2-3 Ohms so "hitting" them with 12V from a reputable "source" :-) for a "touch test" should not hurt them. ("touch" meaning long enough to see the spark and no more)

I would try a nice stiff12V battery and a quick "touch" to see if you can free them after a good soaking.

Stu

Stu, you are really missing out then. Check this out.
http://members.rennlist.com/pbanders/DJetParts.htm

Diagrams and oscilloscope traces galore.

Mr. Anders has done a tremendous service in helping us understand these things. (IMG:style_emoticons/default/pray.gif)

[Valy]

Finally got to upload this.

This is the power at the L-Jet injector terminals. The channel is obviously reversed. You can see that the injector is triggered at 12v and the spikes are created by the injector inductance.

The injection interval is 13ms and the L-Jet injects 2 times per stroke (every revolution) so this picture is at 4615 RPM.
Enjoy.

[r_towle]

Cool, but where is the voltage?

[Valy]

Cool, but where is the voltage?

The voltage is the vertical axis. Each major line is 5V. 0V is where the 1-> points on the left side of the picture, making the bottom of the graph -13.5V (again, the probe +/-were inverted). This means that the injector squirts when the graph is in the lower section.

[stugray]

Valy,

Thanks for the scope capture.
It sure looks like a full 12-13 volts at the injector.
I couldnt figure out the rate...

Every 13ms (period) is ~77 Hz yet the description was high revs....
I dont understand the injector timing for these.

You can even see the injector valve (pintle?) response time at ~2ms.
It would be cool to have a current trace to go along with that voltage trace.

However based on that Voltage trace, the injectors use 12V when running.

Stu

[Valy]

Valy,

Thanks for the scope capture.
It sure looks like a full 12-13 volts at the injector.
I couldnt figure out the rate...

Every 13ms (period) is ~77 Hz yet the description was high revs....
I dont understand the injector timing for these.

You can even see the injector valve (pintle?) response time at ~2ms.
It would be cool to have a current trace to go along with that voltage trace.

However based on that Voltage trace, the injectors use 12V when running.

Stu

77 revolutions/second = 77*60 revolutions/minute=4620 RPM