Not sure what you mean

 

​​​​​they might of been responding to something earlier in the thread, or just didn't follow the testing you've done..

Paul22RE has an injector that tests lower resistance than it should and has verified there are injector pulses on the plug at the injector.

Paul make sure you inspect the harness once you get the upper intake off, look for cracks or pinched wire. Might as well do it while it's there. I don't think this would have caused a single injector issue since they are all tied together, unless it somehow disconnected from the others when it shorted.

 

That's what I'm thinking, possibly wires going to #3 shorted and caused injector to fail? I did notice I accidentally stretched the rear of the harness a bit mounting it back up to the bolt near the front of the intake when I was putting it all back together. I will do another LED pulse test while I wiggle the harness and see what happens before I remove anything. Actually, better probably to just check that there's no continuity on #3 plug while wiggling harness/wire with key off. Called WitchHunter and said they have done thousands of 22RE injectors and only seen 2 or 3 with a bad coil.

 

I'm curious too. Usually, when any coil fails, it goes to open (infinite resistance) or completely shorted (zero resistance). But low resistance? A possibility is that the coil was overheated far enough to fail the insulation internally (so that some, but not all, of turns are shorted).

So whether you do it before you take everything apart, or after the suspect injector is out, I'd try a short pulse of 12v to see if it clicks. Alas, this isn't a perfect test, because if the coil is "weak" it might click with your hand-made (longer) pulse, but not with the one that normally runs the engine. Also, you might have a tiny bit of extra resistance in your harness, which resistance WitchHunter didn't have in their test setup. So WitchHunter got just enough extra current so your injector passed their test (even with a machine-made short pulse), but it won't quite do the trick on your slightly-less-than-100% harness.

This is all just spit-balling. But you might also consider putting one of your known-good injectors into #3, and putting your replacement injector somewhere else. If you continue to have problems on #3, then you can (probably) rule out having received a "new" bad injector.

 

I will put 12V on it when I have it out & let you know if it clicks

 

Just splice in a new connector. All the parts stores have them for about $5. It's doable on number three without removing anything.

 

Could be a bad connection? Dirty terminals on the injector will increase your resistance. I also, very vaguely, recall something about a solenoid plunger position effecting the coil resistance.

If this injector was opened to replace the spring, I didn't think anybody actually did this, not just had its cap and seals replaced.. It may have leaked internally causing a short across the coil.

 

So all 4 injector plugs negative pulse side of the connectors are tied together and should show continuity with each other at all times?

Resistance between the 2 contacts on each connector should be infinite with the key off?

 

They don't fire individually for each cylinder. The fire all at the same time. Want I am saying is just use a wire from number two and put in on number three. Does the problem move?
Change the injector from 3 to 2. Did the problem move?

Now you either splice a wire or send all 4 injectors off to whoever give you an incoming protocol, clean, refurb and spray pattern protocoll.

https://www.yotatech.com/forums/f116...please-160477/

 

Just had an idea: maybe you missed closing up one of the valve adjusters all the way, it moved and you have a constant open exhaust valve?

 

You need to go back and reread the thread, then read my summary. If it's not sinking in then start all over at the top and try again.

Paul, when you get that injector out check for resistance from both poles of the injector to the injector body, I'm guessing there might be a short that shows up.

 

Yes all model years of 22re should have a single circuit on the ground side, as I recall. And even if they don't the ECU grounds #10 and #20 simultaneously.. (Supposedly there is an exception in the RTE, but I haven't ever checked)

​​​​​I want to say yes. I'm not sure if there is, or a need for, a protection diode. Scope, Ray, one of you other guys with EE degrees?

 

I don't have an EE degree, but I doubt you could say what the resistance would be between the contacts with key off. Protection diode would be one confusing possibility. A push-pull circuit could cause there to be some continuity (even a short) with key-off.

As far as I'm concerned, I wouldn't even bother measuring the resistance BETWEEN the contacts. I would have no idea what it would mean.

 

True.
I now read it.

 

I poked into it just a little bit. There is a flyback diode that is built into the driver circuitry, it controls the injector close time to prevent the injector from damaging itself if it were to "slam" closed and prevents it from bouncing back open. Should be able to get a diode mode reading on the ground side.

Diode mode tests are good for comparing with known good circuits.

 

Just wanted to compare any variance from one connector to the other to see if #3 is any different.

But I really just want to make sure #3 is not shorting out when I wiggle the harness.
Probably testing wiring & pulling injector out tomorrow. Will see if injector body shorts to either contact & also see if it clicks with 12V, but will test resistance before and after putting on the 12V to see if plunger moving affects resistance.

 

Ok, pulled #3 and #4 injectors. #3 (bad one) shows 0.6ohms from each pin to the injector body. #4 shows 6.0ohms from either pin to the body.

Pins still show a perfect 13.9ohms on #4. Pins on #3 varies from 3-7ohms. (proper working range is 13.4-14.2ohms)

Putting 12V on #3 did nothing, no clicks nor change in resistance between pins after taking 12V off.

Wiring all looks good so far with no shorts or broken wire as I am wiggling/moving harness and connector wires. #3 & #4 connector wires are almost the same length and I assumed #4 is the longer one, but it really doesn't matter if you swap connectors anyway onto the injectors from what I have learned.

Now just waiting for new injector to arrive & put it all back together. Will do some more tests on the wiring harness and connectors, but so far everything looks good with continuity and no shorting.

 

Good job -- being systematic is often all it takes to locate the problem. Let's just hope that you got to the right answer!