Builds Let's Baseline my new to me 1993 Land Cruiser

[MrMikeyG]

Here's my code 25 and 26 story. I deleted p.a.i.r pretty early since WA announced no more emissions testing would be needed after my first pass as steward of my truck. 3out of 4 of my existing o2 sensor nuts were in really bad shape per visual insp. so I first took a gamble on the Bosch "universal" sensors. (Installed up in manifold location) The codes persisted while I had those installed, and my idle while not rough, was inconsistent depending upon operating temp/time running. I then got the proper NTK sensors and installed those (also up in manifold). My idle cleaned up a tiny bit, but I still had intermittent codes 25/26. I've whined before about not driving my truck very often, so I kind of left things alone for a month or 2. One day while doing some other very minor tasks, I thought I would try and switch my o2 sensor harnesses. I put colored tape on them so I didn't lose track of which was which, swapped them, and the rest is history. No cel since. (over 1 year).

 

[JoeW]

Here's an easy way to diagnose your misfire. You already know how it sounds while misfiring on one cylinder. So, starting on cylinder 1, disconnect the plug wire at the plug or distributor, that choice is yours and restart the car. If it runs worse, that means you have 2 misfiring cylinders now. So shut it off and reconnect the #1 plug wire. Remove #2 and restart. Let's say for demonstration purposes that it sounds the exact same as it did when all wires are connected. That means you have a misfire on cylinder #2. You can do it through all 6 cylinders to verify.
You could also do this with the engine running, but you might get shocked.

Once you know which one is missing, you can use an old plug or whatever to verify spark on that cylinder. Of you've got spark, then time to look at your injector wiring. Iirc in this thread you said you swapped out the connectors. I'd make sure that you have them all fully plugged in as well as that the wires are orientated correctly.

 

[PNWTreeOctopus]

Here's an easy way to diagnose your misfire. You already know how it sounds while misfiring on one cylinder. So, starting on cylinder 1, disconnect the plug wire at the plug or distributor, that choice is yours and restart the car. If it runs worse, that means you have 2 misfiring cylinders now. So shut it off and reconnect the #1 plug wire. Remove #2 and restart. Let's say for demonstration purposes that it sounds the exact same as it did when all wires are connected. That means you have a misfire on cylinder #2. You can do it through all 6 cylinders to verify.
You could also do this with the engine running, but you might get shocked.

Once you know which one is missing, you can use an old plug or whatever to verify spark on that cylinder. Of you've got spark, then time to look at your injector wiring. Iirc in this thread you said you swapped out the connectors. I'd make sure that you have them all fully plugged in as well as that the wires are orientated correctly.

This is really helpful. Thanks for spelling out the procedure. I’m confident in my connector wiring, as I’ve triple checked, but it’s possible that one of the connectors is not fully seated.

I should have some time tomorrow to address it.

 

[PNWTreeOctopus]

Here's my code 25 and 26 story. I deleted p.a.i.r pretty early since WA announced no more emissions testing would be needed after my first pass as steward of my truck. 3out of 4 of my existing o2 sensor nuts were in really bad shape per visual insp. so I first took a gamble on the Bosch "universal" sensors. (Installed up in manifold location) The codes persisted while I had those installed, and my idle while not rough, was inconsistent depending upon operating temp/time running. I then got the proper NTK sensors and installed those (also up in manifold). My idle cleaned up a tiny bit, but I still had intermittent codes 25/26. I've whined before about not driving my truck very often, so I kind of left things alone for a month or 2. One day while doing some other very minor tasks, I thought I would try and switch my o2 sensor harnesses. I put colored tape on them so I didn't lose track of which was which, swapped them, and the rest is history. No cel since. (over 1 year).

Given that they are side by side cats, I wonder why switching them made such a difference, but no codes is great!

 

[JoeW]

No problem. Since it sounds like a single cylinder misfire, it's probably very simple and spark related. It might be a loose plug wire. Maybe start by double checking that each wire is completely seated on the plug and distributor cap and in the correct firing order before starting the disconnect method.

This is really helpful. Thanks for spelling out the procedure. I’m confident in my connector wiring, as I’ve triple checked, but it’s possible that one of the connectors is not fully seated.

I should have some time tomorrow to address it.

 

[PNWTreeOctopus]

I’ll happily post up what I discover tomorrow. I’m curious to learn what I missed.

 

[PNWTreeOctopus]

Additionally I’ll add some thoughts here since I’m enjoying a whiskey on the couch. This most recent round of cruiser maintenance/ baselining related hiccups have provided me huge opportunities for growth in my mechanical knowledge of the 1FZ-FE platform. Lots of firsts for me here and when I finally solve all my lose end issues here I’ll post up a list.

I’ve been pretty frustrated at times at the lack of progress or my own ignorance regarding these systems, but fellas I’m learning so much. I’m grateful to do this work myself and encounter the issues that are developing my troubleshooting skills. These are not possible to buy, and are valuable.

I guess when I think about the purpose of this endless bawling for my rig, the goal is overbuilt/ ultra reliable. I chose the 80 series, because it runs well in difficult environments and is overbuilt/engineered for its people hauling purpose. It easily takes my family and I beyond the map. However, s*** happens and things break. I’m finally feeling like I’m gaining the knowledge to unfuck myself in the lonely places where I prefer to be. I’m not there yet, but I’m leagues ahead of where I was when I first started exploring in 4WDs. It’s nice to know that the best tools for my repair kit are these skills you all are helping me hone.

 

[PNWTreeOctopus]

Update:

Ok, gotta call it for today, but my misfire is occurring no.2. I pulled the wires on the distributor cap with it running and there is no change for no. 2. Plenty of sparks from the distributor wire to the cap.

I switched plugs with no.1 cylinder and no change when I started removing wires again. I tested ohms on the wire and we were in the 9ohm range-well below 25 ohm max, so I’m assuming the plug wire is good?

I used the mechanics stethoscope and listened to the no.1, 2, and 3 injectors. 1 and 3 sound the same, but 2 is much quieter. In no.1 and no. 3 I can hear a rhythmic clicking/ ticking which is the fuel pulse that is absent on no 2.

I then disconnected the no.1 injector to confirm this is indeed the injector pulse sound, which stopped and started when I unplugged and plugged the no1 connector back in. For s***s and giggles I tried to push the no.2 plug on tighter and I suddenly heard clicking/ pulsing in the injector. It would cease if I didn’t push it sightless towards the VC.

So to summarize no2 is misfiring because the injector is not pulsing due to a poor connection. I was grateful for the use of my cheesy stethoscope to figure this out since my finger won’t reach the no.3 injector.

I’m not sure if my pins are in poor shape or if they are not deep enough. I’ve run out of time for now.

Suggestions welcome.

 

[TYM4FUN]

Update:

Ok, gotta call it for today, but my misfire is occurring no.2. I pulled the wires on the distributor cap with it running and there is no change for no. 2. Plenty of sparks from the distributor wire to the cap.

I switched plugs with no.1 cylinder and no change when I started removing wires again. I tested ohms on the wire and we were in the 9ohm range-well below 25 ohm max, so I’m assuming the plug wire is good?

I used the mechanics stethoscope and listened to the no.1, 2, and 3 injectors. 1 and 3 sound the same, but 2 is much quieter. In no.1 and no. 3 I can hear a rhythmic clicking/ ticking which is the fuel pulse that is absent on no 2.

I then disconnected the no.1 injector to confirm this is indeed the injector pulse sound, which stopped and started when I unplugged and plugged the no1 connector back in. For s***s and giggles I tried to push the no.2 plug on tighter and I suddenly heard clicking/ pulsing in the injector. It would cease if I didn’t push it sightless towards the VC.

So to summarize no2 is misfiring because the injector is not pulsing due to a poor connection. I was grateful for the use of my cheesy stethoscope to figure this out since my finger won’t reach the no.3 injector.

I’m not sure if my pins are in poor shape or if they are not deep enough. I’ve run out of time for now.

Suggestions welcome.

Good. Check the condition of the male terminal and the injector nub that it mates with for condition. If your male clip is damaged let me know and I can send you a new terminal to help you out.

 

[TYM4FUN]

Unless you have loose wire crimps at that location, that is a different and possible issue.

 

[PNWTreeOctopus]

Good. Check the condition of the male terminal and the injector nub that it mates with for condition. If your male clip is damaged let me know and I can send you a new terminal to help you out.

I’ll have some time tomorrow to work on the wires. Getting closer! I’ll let you know what I discover. Thanks for the offer for a terminal.

Unless you have loose wire crimps at that location, that is a different and possible issue.

 

[Dusten]

You repinned all the injectors.
Take and look at #2 vs #1 see if there is a noticeable difference.

 

[TYM4FUN]

You repinned all the injectors.
Take and look at #2 vs #1 see if there is a noticeable difference.

Thanks, sorry late to the party and must have missed/forgotten this.

 

[PNWTreeOctopus]

Thanks, sorry late to the party and must have missed/forgotten this.

No need to apologize, your contributions are very helpful.

 

[PNWTreeOctopus]

You repinned all the injectors.
Take and look at #2 vs #1 see if there is a noticeable difference.

^^ this is my next move. Thanks Dusten!

 

[PNWTreeOctopus]

Hoping for a simple solution today. So upon inspection and some more testing it appears that the female terminals in the harness side connectors are slightly, for lack of a better word, compressed and moving the connector while it’s connected to the injector about 1-2 mm toward the VC helps it make its connection. Just so we’re all on the same page the connector is positively locked on the injector—that’s not the issue.

I’m not sure if I compressed the terminals
some how removing them, but there probably isn’t really room to put on new terminals without pulling the upper intake and everything again. I’m going to try and persuade them to make a good connection.

Here is injector connector no.1—no issues:

And here is no.2 with issues:

The difference are very slight and not easy to see with the camera and the position of the phone etc.

 

[TomH]

Check that there isn't an extra orange gasket on #2. It kind of looks like there is but if it is clipping on the injector then probably not the problem.

Get a view of the injector and make sure the pins didn't get bent or folded over.

Could be a bad injector.

 

[PNWTreeOctopus]

Solved.

I had a good look look at the terminals, they are clipped in properly and in really reasonably shape—nothing remotely like the horror of my NSS stuff. It looks like the male terminals just aren’t making contact thing them…sort of a hole in one/ swoosh kind of situation. Moving the terminal ever so slightly made contact and the injector fired right up. So I bent the injector pins towards the intake manifold about 1-2mm nothing to weaken them or damage them.

That’s all it took. I fired it up and the injector is happily clicking away. I wiggled the injector harness a bit trying to simulate rough roads etc, but I couldn’t get it to stop working. I then took the no.1 and no.2 connectors off and gave them more dielectric grease as I had cleaned them out for the photos and trouble shooting and retested the connection. I can’t press it to make it stop. I pulled the EFI fuse and cleared my codes so we will see if that was my issue. I’ll double check the timing again now that all the cylinders are firing.

Someone might object to the horror of bending my terminals, but this seems like a reasonable solution given that otherwise it’s re pinning the terminal and that requires a lot of tear down and $$$ in a few expensive gaskets.

I’m moving on, but your comments, pro and con are most welcome as always.

 

[TomH]

Someone might object to the horror of bending my terminals, but this seems like a reasonable solution given that otherwise it’s re pinning the terminal and that requires a lot of tear down and $$$ in a few expensive gaskets.

I’m moving on, but your comments, pro and con are most welcome as always.

I checked the wiring repair manual and it looks like you are good, not that it really matters at this point.

 

[PNWTreeOctopus]

I checked the wiring repair manual and it looks like you are good, not that it really matters at this point.

View attachment 2925773

Better lucky than smart: I win again!