Unsolved injector mystery
 

Ok, I'm just gonna lay everything out for you guys.

From the beggining, I had an air leak at my second injector seal. I pull everything off (intake, hoses, fuel line) and replace the whole injector and a new seal. I also took the opportunity to replace all the wires going to the injectors b/c all the plastic was rotted (spliced all new wires and plugs). When I put it all back together and tryed to start, nothing happened. All it would do was turn over.

I got out and kinda checked a few things but nothing helped. That was three days ago. Since then I'v spent every waking moment trying to think of what I did or didn't do.

Since it ran fine before, I figure it has to have something to do with what I did. But just to be safe I tested the spark and its all good. I also replaced the fuel pressure regulator.

I am completely stumped, somehow fuel is not making i into the cylinders. Is is however making it to the rail with signifigant pressure, so the pump is working. And I think I tested the injectors correct by checking for continuity between the battery and the injector wires.

Help!! :bang:

check for injector pulse with a noid light , check & see if you blew a fuse .

your going to have to check the injector plugs with a noid light first..to see if the injectors are getting power. my guess would be that they arent. then look to see what color the wires are...and test the wires at the computer end. Thats in the kick panel on the passenger side. if they are getting power at the computer...then your problem lays in the harness. the injector wires can come apart in the harness. This happened to mine. They came apart in the harness behind the battery. Maybe grab the harness and squeeze it some in that area. see if that helps...but if it does help...then ya know ya got a loose connection in there that needs to be fixed by cutting into the harness and re-connecting them. hope this helps, good luck

I fixed the wire harness a while back when it came apart inside.

Could someone please discribe in as graphic detail as possible how to use the noid light. For some reason I just can't figure it out. Thanks

Wait, is a noid light the same as the screw driver looking thing with the light inside?

noid light is a light that has 2 prongs to fit into the harness at the injector plug. then when ya turn the motor over it sends a signal to the light to flash on the injection pulse. this way ,ya know if your getting power to the injectors. you need to test each plug on the harness where the injectors plug in at.

where can I get one of these? And how could it have gone bad?

What confused me is that the plugs are getting 11-12V and a ground when the key is in on position. Is that the same as a pulse??

http://www.carburetion.com/images/noidlights.gif <~~ A picture of noid lights, you can google and find where to get them im sure.

Ok, so I got the noid light and tested all of them. No light up. What does that tell me?

I'm wondering if the replacement injector (from ebay) could be causing this. If there is something wrong with that one, could it mess up the others?

When I spliced the new connectors, I did it in a way that all four spliced ends are jumbled together. That may be tough to imagine, sorry. Would that matter?

If you've tested the injector plugs on the harness and your not getting any noid lights to flash when turning the motor over...your ground needs to be connected to the intake for this. no lights means you need to start looking at the harness its self. after youve tested to make sure you have power from the computer in the kick panel....if you have power to the injector wires at the computer...and no power at the injector plugs...then your problem must be somewhere between those 2 points...that leaves you with the harness to look at more closely. hope this helps, good luck

You know what...... that helps so much. Sometimes it needs to be slapped at you like that. For so long I'v been thinking that it was something I did wrong, But I have to face the fact that something crapped out and it might just be a coincidense. Your right, it has to be the harness somwhere.

Thanks

i just put a new head on my 4 runner. everything went fairly smooth...cept i was only running on 3 cyl when i finished. I was getting spark from the dist and wires and plugs. so i looked at injectors. then i realised i was only getting fire to the rear 2 injectors. none on the 2nd and a weak spark on the #1. i found this out with the noid lights. then i looked at what color the wires were that had no fire. then went to the computer and tested thos there, and they had fire...so i knew it was somewhere in the harness. so i cut it open and found my injector wires in the harness were not connected. i connected them back to where they came unhooked from and retaped the harness. no problems since. hope this helps

Wait, wait, wait. Do you mean you wired them as if they all fire at the same time? If so, there's your problem.

I believe they fire in pairs, if not individually.

Order does matter, either way.

Common misconception. The ECU indicates two banks of injectors, which mean that they were designed to fire seperately. If you pay attention the the factory wiring diagram, both banks are merged at in the harness, the only exception (possibly) is the 22RTE.

I've enclosed the diagram that explains this at the bottom of the post.

Now that I've said that, it's odd that you've found your injectors "jumbled".. Can you post a photo?

If you've got 12v at the injectors between a ground point and one injector terminal, you're 50% of the way there.

The next thing I'd check is continuity between one side of an injector clip (you're looking for the ground side) and the ECU itself.. Just unplug the ECU harness and probe the "E01" pin.


http://lakebox.dnsalias.com//photos/...jectorbank.jpg

Ok, I'll try to clarify jumbled. Imagine a stockade, like the ones that people use to be put in while they were punished or something. That is the sort of splice I used; were the top closes over the bottom inclosing both wires in the same clamp. What I'm worried about is the clamp is made of metal which means that the two spliced wires are actually connected through the metal.

So if you look at your plugs that go onto the injectors there are two female prongs, one for each male prong on the injector. Each prong has its own wire that is individualy shealthed. I unsheathed both of them to splice on the new connector but now, through the metal splicer, the wires are touching. This is the case with all four connectors.

Would that have an effect on the pulse? Would that channel the pulse to the ground before it made it to the injector??

[QUOTE=Lifelongtoy;50572972] I unsheathed both of them to splice on the new connector but now, through the metal splicer, the wires are touching. This is the case with all four connectors.QUOTE]

For the sake of communication:
Each injector has two wires. You've patched these somehow and the two wires are touching.
Yes. That would cause a serious issue and may result in bigger problems.
The two wires are isolated for a reason, allowing them to touch is a smaller version of putting a wire across two terminals of your battery (just for drama sake).

That'd do it.



http://lakebox.dnsalias.com/photos/1...d/DSC06178.JPG


:-)

Ok, so I spliced them correctly without the wires touching. Still won't start but it is definetly trying. I feel so close. It sounds like its getting just a little bit of gas allowing it to catch for a second, but that's it.

The noid light are lighting up, but not as bright as I would have thought.

Nice Shepard. Man, they look identical.

Done, it was the splice. Just didn't tighten the intake at all.