Nice, I wish he was close enough for me to bring my Yote to him!

 

OK guys, I just got my truck back from my toyota factory guru and it runs great. Even though I had a relatively new o2 sensor on the truck and argued when he called me and said the 02 readings were way screwedup, we tried a new one anyway, just a generic sensor since he cut the end off the wire as it was mounted to my header downpipe just in front of the cat and didnt use a factory plug. I also had factory wires and cap that were only 1 1/2 yrs old ,but the coil feed into the cap was green and corroded. Replaced the cap and coil wire (He said that seemed common on 22r's for unknown reasons) FIXED IT COLD! Truck runs great from cold to normal temp. Suggestions-If you can get an analog volt meter(easier to read for 02 sensors) and set on 0-1 volt ,either disconnect the 02 sensor and probe it directly or use the pin on the dlc1 connector under the hood. You should see a back and forth fluctation from 0 to .9volt. Higher voltage on accel and close to zero on decel when system goes into fuel cut. If it is stuck either way or not fluctuating ,try replacing it first. He reminded me that at least in the 87 up that the system is in closed loop even at idle after warmup. The reason they ran good after 2800 is that probably we were hitting wot on the tps and that does take to open loop and the bad sensor is ignored. As to the wires, it must have contributed some, but the sensor was primary in fixing the truck. WE think that possibly the new headers from Pacesetter I installed about the time this was all going south may have finished off the sensor by coating it with something in the tubes from production, but thats just a theory.
Hope this helps guys-

 

my motor and efi is out of a 85 motor home, its in an 88 truck with an 88 o2 sensor and 88 fuse panel. the 85 ecu is installed. could the year difference make the problem? i have the intake torn off right now and was going to put a carb on it. i think ill try salvaging the efi if i can

 

Wow, you got a kind of gumbo goin on under the hood. Really I think most of the efi stuff is compatable from 85 thru 88. Since the intake is off and you are thinking of carbing it, no way to be sure if the prob was like mine,in the o2 sensor, or something else. If you do decide to reinstall the intake as is ,you can still test the sensor to see if it is even responding to changes in the a/f ratio using a volt meter. If it doesnt indicate basically higher voltage under accel and lower on decel or idle, it is probably bad. A sensor can be had for 50-60 bucks, and if that fixes it ,a lot cheaper than a carb. Just a few things to think about, anyway.
Good luck

 

Seems to be that the truck is fixed. Before I left for holiday I put a new O2 sensor in it. I figured it's worth a shot, since the only error I get from the ECU is for the O2. I tested all the wiring and it checks out great. Plus a new sensor is only $18, so what the hey.

When I took off the old sensor from the header collector tube I noticed that the ceramic boot was cracked and that the wire inside may be cut. I put the new sensor on and it has been running great ever since!

Thanks for all the help and suggestions from everyone, and especially oldtoyguy.

 

I have an 86 with a pace setter header. My problems are not as serious (yet) as you all described, but i have rough idle problems that i've been chasing. I'll be changing the O2 sensor out now. Thank you all, and God Bless Yotatech.