- Thread starter
- #61
Thank you! I am ready to be wheeling it instead of working on it! LOL
Builds Caitlyn the 2nd Gen 4Runner-ish (1 Viewer)
- Thread starter CreeperSleeper
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- Thread starter
- #62
A couple of days ago, I finally got my old dinosaur laptop running XP to download and work with an old version of Toyota Techstream. Armed with that and a FSM, I started digging into finding out what is causing the high idle.
It was a little weird using a computer for diagnostics. This will definitely be a learning curve for me.
Anywho… I pulled the codes and found P0125. I cleared the code. Fired the truck up and played with the real time monitoring. That was very cool, but I really didn’t know what I was looking at. She was still idling high and my computer needed a reboot, so I unplugged it and started doing some “old school” diagnostics.
It looked like the throttle cable was at a funny angle, so I adjusted that. It’s in rough shape so that may need to be replaced at some point, but I know that is not the issue because I was running the engine with the throttle cable disconnected. Another suggestion was the IAC causing problems. With the engine running I unplugged the IAC and the engine instantly sounded funny and running rough. It didn’t die but I didn’t give it any throttle either. With that I know the IAC is doing something, just not sure what.
I drove her a bit (maybe a mile), just to see what would happen. The MIL was on, she wouldn’t idle down by herself, and I got light constant throttle hesitation twice. Got back to the house and plugged in Techstream. This time I got two codes: P0125 (again) and P0505.
P0505 sounded promising and there was a “freeze frame” stored showing what was going on when the trouble code happened. I wish I know what it all meant. LOL!
After that, I pulled out my FSM to see what it said about those codes in the diagnostics section. I got this:
And this:
So from what I can deduct, there is something going on with the O2 sensor upstream of the cat and an issue with the IAC. I had to move on to another project, so I put my tools away with the game plan of chasing the P0505 code first. That seemed like the correct path to fix the high idle. Then it occurred to me that I caused the P0505 code when I unplugged the IAC….
So, I guess I will start by chasing the P0125 code. LOL! That being said, does anyone have any experience with the upstream O2 sensor causing high idle? If you pull up to a stop sign, the idle will hang at 1500 or so. If you blip the throttle, the idle will drop to 600-ish and stay there until you give it gas again. I can replicate this in the garage, too, so it is not load dependent. Let me know what you guys think!
It was a little weird using a computer for diagnostics. This will definitely be a learning curve for me.
Anywho… I pulled the codes and found P0125. I cleared the code. Fired the truck up and played with the real time monitoring. That was very cool, but I really didn’t know what I was looking at. She was still idling high and my computer needed a reboot, so I unplugged it and started doing some “old school” diagnostics.
It looked like the throttle cable was at a funny angle, so I adjusted that. It’s in rough shape so that may need to be replaced at some point, but I know that is not the issue because I was running the engine with the throttle cable disconnected. Another suggestion was the IAC causing problems. With the engine running I unplugged the IAC and the engine instantly sounded funny and running rough. It didn’t die but I didn’t give it any throttle either. With that I know the IAC is doing something, just not sure what.
I drove her a bit (maybe a mile), just to see what would happen. The MIL was on, she wouldn’t idle down by herself, and I got light constant throttle hesitation twice. Got back to the house and plugged in Techstream. This time I got two codes: P0125 (again) and P0505.
P0505 sounded promising and there was a “freeze frame” stored showing what was going on when the trouble code happened. I wish I know what it all meant. LOL!
After that, I pulled out my FSM to see what it said about those codes in the diagnostics section. I got this:
And this:
So from what I can deduct, there is something going on with the O2 sensor upstream of the cat and an issue with the IAC. I had to move on to another project, so I put my tools away with the game plan of chasing the P0505 code first. That seemed like the correct path to fix the high idle. Then it occurred to me that I caused the P0505 code when I unplugged the IAC….
So, I guess I will start by chasing the P0125 code. LOL! That being said, does anyone have any experience with the upstream O2 sensor causing high idle? If you pull up to a stop sign, the idle will hang at 1500 or so. If you blip the throttle, the idle will drop to 600-ish and stay there until you give it gas again. I can replicate this in the garage, too, so it is not load dependent. Let me know what you guys think!
Last edited:
- Thread starter
- #63
Finally got time to warm the truck up and monitor the sensors. Both 02 sensors passed the heating cycle, but the front sensor is showing 0 volts. The sensor that is in there looks new-ish, but I bought a new Denso to replace it. I go to unplug the sensor and the PO hard wired it!
So now I don't know if the sensor is actually bad or if it was wired wrong...
Finally got time to warm the truck up and monitor the sensors. Both 02 sensors passed the heating cycle, but the front sensor is showing 0 volts. The sensor that is in there looks new-ish, but I bought a new Denso to replace it. I go to unplug the sensor and the PO hard wired it!So now I don't know if the sensor is actually bad or if it was wired wrong...
- Thread starter
- #66
A HUGE thanks to @tonsofun for coming over and helping me with Caitlyn last night. We (he) was able to hard wire the rear O2 sensor and move the pigtail to the front. There is a lot less room around the front sensor, so that made sense to switch it around instead of hard wiring the front sensor again. I wouldn't have been able to do it without his impressive soldering skills and ability to see what colors the wires were. LOL!
I was full of hope as I pulled her out of the garage for a test drive. I made it about two miles before the MIL came back on... Now I don't know what to do. She has also started hesitating on light throttle and accelerating from idle. This has been getting progressively worse the more I drive it. It doesn't do it all of the time, so it is difficult to figure out why and when. Just guessing, but I may have been running it in open loop and short trips enough that the spark plugs are fouling since it is running so rich. Or it could be a non-related fueling issue. As for the code, I'm really not sure. I have been clearing the code through TechStream and I haven't disconnected the battery. Maybe it is stored in the ECUs memory, but that seems like a long shot to me.
My current plan of attack is to start by pulling the spark plugs and see if I can get a read on them. I will also disconnect the battery to reset the ECU. After that, I will try to do some live monitoring on TechStream to see if the ECU is reading any voltage from the front O2 sensor. I am hoping that all of that gives me a direction to jump because I am running out of ideas. If anyone has any suggestions, I would love to hear them!
Looking at the calendar, it is becoming clear that Caitlyn may not be ready by Rubithon. I have so much to do and if I can't get her running correctly in the next few days, I don't think I will have time to have it dialed in enough to trust it on that trail. I really don't want to be the guy with issues out there! I may need to start thinking of alternatives, which from what I can see, I don't like any of them. I am trying to stay positive and motivated, but it is proving difficult to say the least... Does anyone want to buy a really cool 4Runner that needs some work? (Half joking)
I was full of hope as I pulled her out of the garage for a test drive. I made it about two miles before the MIL came back on... Now I don't know what to do. She has also started hesitating on light throttle and accelerating from idle. This has been getting progressively worse the more I drive it. It doesn't do it all of the time, so it is difficult to figure out why and when. Just guessing, but I may have been running it in open loop and short trips enough that the spark plugs are fouling since it is running so rich. Or it could be a non-related fueling issue. As for the code, I'm really not sure. I have been clearing the code through TechStream and I haven't disconnected the battery. Maybe it is stored in the ECUs memory, but that seems like a long shot to me.
My current plan of attack is to start by pulling the spark plugs and see if I can get a read on them. I will also disconnect the battery to reset the ECU. After that, I will try to do some live monitoring on TechStream to see if the ECU is reading any voltage from the front O2 sensor. I am hoping that all of that gives me a direction to jump because I am running out of ideas. If anyone has any suggestions, I would love to hear them!
Looking at the calendar, it is becoming clear that Caitlyn may not be ready by Rubithon. I have so much to do and if I can't get her running correctly in the next few days, I don't think I will have time to have it dialed in enough to trust it on that trail. I really don't want to be the guy with issues out there! I may need to start thinking of alternatives, which from what I can see, I don't like any of them. I am trying to stay positive and motivated, but it is proving difficult to say the least... Does anyone want to buy a really cool 4Runner that needs some work? (Half joking)
I’ve dealt with a few 3.4s in the past that threw codes for o2 sensors that ended up being bad MAFs (after changing the o2s). Have you tried cleaning the filament? One we cleaned, the other had to be replaced.
- Thread starter
- #69
LS swap.
That is the long term dream: LS, auto, Atlas... But that is a long ways away.
Hmm. That is something to think about. It wouldn't hurt to clean it. I will add that to the list. Thank you!
- Thread starter
- #70
Well, it is time to close this chapter. A guy messaged me and asked just how "half joking" I was about selling Caitlyn. After 100's of text messages, a ton of photos, and one sorry excuse of a video call we struck up a deal. Last weekend I drove Caitlyn out of my garage for the last time and loaded her on a trailer to meet her new owner.
Both of us drove 5 hours to meet in a central location. We looked over the rigs and shook hands on the deal. Caitlyn will get to make incredible family memories and I got Agatha. She is a '83 Toyota based buggy that I'm sure will become a member of the family.
And she is already making herself comfortable in her new garage. LOL!
Both of us drove 5 hours to meet in a central location. We looked over the rigs and shook hands on the deal. Caitlyn will get to make incredible family memories and I got Agatha. She is a '83 Toyota based buggy that I'm sure will become a member of the family.
And she is already making herself comfortable in her new garage. LOL!
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- #72
I was actually surprised, but very happy. I know that the Runner will be a great rig for him and his family.
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- #74
Rigalo? LOL!
I had my 80 for a long time. I just haven't found a rig I felt comfortable with since than. Well, other than the black and tan truck... I should have never sold that one. Anyway, I am going up tomorrow for some easier trials to get a feel for the new girl and (hopefully) will be in Crushers on Sunday!
I had my 80 for a long time. I just haven't found a rig I felt comfortable with since than. Well, other than the black and tan truck... I should have never sold that one. Anyway, I am going up tomorrow for some easier trials to get a feel for the new girl and (hopefully) will be in Crushers on Sunday!
