RAD4Runner

Forget the pairing. Bottomline is they all get pulsed at the same time. Whether #10 or #20 both pulse at the same time, I don't know, but Either #10 or #20 pulsing will fire ALL 4 injectors.

I guess, yes, you have air-fuel mixture already waiting in the intake manifold waiting; For how long, depends on ECU programming.

Probably something to do with resistance of the injector and/or the wiring and how good the connections are.

One reason I like the 22R-E is it is easier to fix and/or inspect than modern engines so I would use that to our advantage. Your choice; either inspect the harness, connections and injectors at home or do it when it stalls while you're in the middle of nowhere.

Co_94_PU

iTrader: (-1)

Definitely worth checking the resistance, hot verses cold, also while wiggling the harness, and jiggling the connectors at the injector. This will help point to bad splices, spread or corroded plugs, and damaged (heat soaked) injectors.

Do this "end to end" by back probing the harness at the ecu, that means unbolting the ECU disconnect the plug and inserting the meter leads into the back of the plug (where the wires enter) along side the leads making sure they touch the metal.

There isn't room on the ECU side for the average size of meter probes, so the back side is the way to go. IF you must you can probe the ECU side of that plug using T-pins (found in the sewing department of your local big box store) and clipping the leads to these. Remember to put them along side not into the plugs to prevent spreading the female lug.

XJNKY

I've heard that a lot, but from my seat... not the experience I'm having. I've owned a lot of vehicles plenty of them 20+ years old, and this is the first one I've ever had to go to this level of diagnostic for. But... almost everything else has been OBDII also...

And I'm not driving the truck. It isn't even insured at the moment. So it isn't going to strand me anywhere. I recognize I might have to tear into the harness. It's been said here already, and I believe it. I'm not arguing against that suggestion, I just dread it. I also am seeing that as my last ditch effort, and am trying to make sure there are no other options before it comes to that. Wiring is not my specialty, by any means. And I fear doing as much damage as good once I start cutting into things.

Also, not previously disclosed, but relevant, is I'm fighting with a relatively troublesome neck/shoulder injury. And hooking noid lights and checking resistances is relatively easy. Stripping parts of the engine back off and tearing into harnesses is a dread for more reasons than "I don't wanna".

XJNKY

Good advice. Noted. Right now, I can't even tell you where the ECU plug is, but I bet it would make more sense once it's in front of me.

RAD4Runner

ECU is in right-side kick panel. I don't remember the orientation but IF, and only IF, the connector is on the bottom (as in the picture) you may not have to unscrew it. Anyway, un-mounting the ECU should not be as difficult. To probe, it's best to have an assistant; One of you to hold the meter and test leads in place and watch the reading as the other to wiggle all the connections.

Exactly. NEITHER SCHEMATIC NOR WIRING DIAGRAM shows exactly which connector pins are ECU #11 and #20. Best to just look for the White wire and the White wire with red stripe, AND make sure there are no other 'White wire and the White wire with red stripe" on that ECU connector.

coryc85

Also, if you search through a couple of Terrys87 threads, he has rehab'd probably more Toyota trucks than anyone on here and I believe he has several times mentioned issues with the factory injector wiring. His threads are pretty organized and the first post sometimes has links to the relevant issues. Almost certainly he has some pics of how he troubleshoots the injector harness...might give you some ideas and some easy things to check.

Ok well I typed all that, then I said why don't I just go search for it myself....here you go https://www.yotatech.com/forums/f199...l#post51897320

RAD4Runner

Yes, and I think Terry also replaced his injector connectors with new ones. Good info if O.P. needs to do same.

Co_94_PU

iTrader: (-1)

Pinout is in the efi and iirc also in the wiring diagram section..


These are shown from the back side, or rather looking into the ECU pins..

So left connector second to the right top and bottom. Verify the wire colors.

You won't need someone to hold leads if you insert them from the back along side the wire and lug, or use tpins as I described.

YotaRick27

I'm not here for assistance but I am here because I am having the same issue..1986 Toyota pickup 22RE 183K fresh rebuild and ran great for about 1000 miles, Starts and runs cold, once warm has a nasty idle then dies I got stranded(4 times now) Went through all the usual symptoms and even picked up a LCE fuel pressure gauge.to see if it was a fuel pressure issue. Fuel pressure is fine and even jumps up(5-6PSI) when FPR vacuum line is removed. also picked up a new green plug coolant sensor and tested the ohms before i even left the parts store. Fuel pressure does not drop after engine is shut off. bypassed F&B+ pump works great. I did see somewhere that it might be the backpack that sits on the coil (ICM). Does anyone have a way to test the Ignition control module?

YotaRick27

Pull and see if the CSI is spraying fuel once it dies and wont start again.

XJNKY

Thank you. I'm a little pressed for time right now, but I will come back to this.

Apparently I stopped getting notifications for new posts here...

XJNKY

Thank you sir. I do have to ask though, is this for an 88? I've seen several mentions of different years having different ECM's and pinouts.

XJNKY

Hey Rick. Welcome to my thread. Feel free to piggy back here. It sounds like we're in the same boat and I don't mind sharing the paddle.

I will say, for me, I didn't pull the CSI to see if it was spraying. That was an early suggestion. The thought being that it might be flooding instead of not getting fuel. I ruled that out by unplugging the CSI and it still not helping. Plus, my plugs don't look fowled, and it will start and be cranky about it on ether or some gas poured in the intake tube. So I determined... nay, assumed it was *not* getting fuel instead of getting too much.

XJNKY

Alright guys. Thank you all for the detailed technical advice. I'm on a short break at work here, so I don't have time to digest it all right this second. I stopped getting email notifications for some reason, so I didn't know there were new posts. My apologies.

Right now I'm struggling with a neck/shoulder injury, and it's going to delay some of these suggestions. I go for an MRI next week. The results of that might delay this a bit more...

But, when I can't work on it, I can at least think about it. And I've found I save a lot of headache just sitting and thinking through things before "doing" things.

I'm still perplexed why it would start on 3 injectors with the noid light, but won't start when I plug it back to the injector. So I took the wiring diagram RAD4Runner provided across the hall to our resident Sr. Electrical Engineer, and explained how the injector worked. + to both sides, and then drop one to ground to pulse. Explained the simultaneous pulse and the tied together grounds. Then explained the phenomenon of starting on the noid light, and not on the injector. It took him about a minute of looking at it and confirming the setup I just described. Then he was like "Oh, that's simple".

His theory: You have a common hot coming in, and a common ground. The switching happens in the ECM. So, all 4 injectors are essentially in parallel. He said it was simple. One of the injectors, the one I'm unplugging, has to have a short in it. When the other end is dropped to ground, it is acting like a straight wire connection. Electricity follows the path of least resistance, and all the juice is running through that one injector. They're imbalanced. When I plug the light in, it is providing more resistance than the short, and evening the other 3 injectors out. He said if I measured them hot, he was pretty confident I'd find that one injector would have very low impedence.

Makes sense to me. I at first questioned why it would run fine hot, and not restart, if that one injector was essentially providing a bypass, why wouldn't it do it running. But, heat soak. Thresholds are finicky things. Sometimes 1 degree can make a difference. And now... it's taken to idling pretty rough when it gets warmed up, where as when this problem was first manifesting, it would idle just fine hot.

I think it's a theory with some merit. So, as soon as I can get 2 fully functioning arms, I'm pulling the upper plenum and measuring resistance across all 4. Just need to figure out a way to do it hot. Maybe hit them with a heat gun for an unscientific approach.

Any of you guys have any thoughts about that theory?

RASALIBRE

http://www.pirate4x4.com/forum/login...2485449?page=1

RAD4Runner

Sounds like a legit theory but I prefer to go simple first so, I still think it's those crimps.
Ask Yotarick.

YotaRick27

XJNKY

Well... crud.

First and foremost, Rick, can you post me a link? I thought I'd be able to find it from your profile, but apparently not. Also, congrats. Always happy to see someone else figure one out.(Nevermind, found it. Sorry that wasn't the answer. Mine has acted like it might have been fixed a few times also.)

So, I've been picking at it little bit by little bit. And tonight I realized I had everything disconnected, so I went ahead and pulled the plenum. Injury not allowing me to do a whole lot at a time.

Here's some notes. But first, I want to say... I'm not ignoring any advice. I'm just tackling it in the order I think seems most likely/ easiest to test.

LCE says injectors should be 2.5 Ohms. I assume that's at a standard 70F. At 40F , #2-4 measured 2.0 Ohms. #1 measured 1.8 Ohms. So I pulled them, and used a heat gun to warm them up... pretty good... and #2&4 went to roughly 2.4-2.5 Ohms. #1 went to 3.2 Ohms. Then 2.2 Ohms. Then 2.5 Ohms.
...
For some reason, I was having more trouble getting #1 to stabilize, but I don't have clips on my multimeter, just probes, and it was pretty warm so I was trying not to touch the body. I'd be ok calling the variation user error, but I didn't have that trouble with the other ones. But it settled about the same as the others in the end.

So... I'm not 100% convinced that killed that theory, but... for the moment, they look functional. I even wired them and touched them to battery terminals. They click (warm).

So before I go cutting into the harness now that I have the plenum off (well, I guess I should have tried checking for pulse at the computer before I took it apart... crud), I do want to say... I found something when I got it off. Apparently I missed a ground wire, cause it was just chilling in there, not bolted down to anything. I'm even sure where it was supposed to be bolted. It has a rectangular indent on it, but I can't figure out what that would have been mated to.

Now... I've been trying to figure out how this could be my issue. As best as I could tell, was touching nothing. And the engine was running. Injectors were firing. So it obviously wasn't critical to that circuit... cold.

I guess I'm going to bolt it down to something... But should I assume that's my issue? It isn't in the fuel harness specifically, just sort of runs into the main harness. And I'm not seeing a ground symbol on the fuel circuit diagrams. But, it does look like it has 2-4 wires going to it

XJNKY

Also (sigh) further admission of guilt. I was so convinced that I was going to find a bad injector, I ordered new ones. I never order parts off of ebay, but these 1 year injectors are so hard to find... I ordered rebuilt's off of ebay...
https://www.ebay.com/itm/141743883332
Quick note. They are not true 4 hole. They are 1 hole injectors, with a 4 hole cap over them, that looks like it was drilled by a child with a rough fixture. Not real happy with them, and the dimensions are a little off from the old ones (which are a genuine 2 hole). But... I'm feeling impatient I guess.

In case anyone is wondering... yep, I regret that impulsiveness. Think I should send them back and eat the $30 on restocking and shipping, or just throw them in since I have them? They all measure 2.8 Ohms at 70F.

XJNKY

RASALIBRE, I just wanted to point out... this link just takes me to the Pirate homepage. Was there supposed to be a thread here?