duck trapper

trying to identify a fat brown colored wire.it is shielded much like a coax . It seems to be originating from a cylender head. It is visible between #4 & #6 fuel injector. it has a black wire in the center of the shielding wire. It terminates in the small ECU plug, but before it does the shielding wire is spliced together with shielding wire from a simillar silver wire that also has a black core wire. Both black wires go to the small ECU plug. This was found in a 91 SR5 pick up 5 speed. I believe it was a California truck, if that enters into it.

duck trapper

I forgot a minor detail: This is a 3.0 L V6.

BC Rider

DuckTrapper:


If you are saying that it comes out beneath the intake manifold between the 4 and 6 cylinder (ie. back of engine on drivers side) then it is likely the knock sensor wire. Not sure what you mean by ECU plug. The knock sensor plugs into the main wire harness just below the throttle body.

duck trapper

BC , I was just looking at the schmati and there are only 2 black wires. One knock sensor and the other is marked "Test connector>oxygen sensor.
What I meant by ECU is the computer behind the kick panel on the passenger side. Three groups of wires plug into it. The smallest has 11 wires termanating in it. Two of those 11 wires are the black ones that are shielded with braided wire.
Yes it comes out beneath the intake manifold.
Thanks BC!

^VooDoo^

Knock sensor, THe only other simular coax is the O2 sensor and it comes up on the passenger side fender and goes to the test point hanging on the side of the fusebox, From there they both go to the ECU, Yes they are connected on the same plug as pins 5 knocksensor and 6 O2 Sensor.

For 93-95 there is a data link that both O2 sensors go to before it goes to the ECU, But still use the same plug and pins at the ECU for the main O2 sensor and second to another set at the ECU, Pin 10.
If you want the O2 heater power pins I can look those up but I cant say outright, Toyota changed the labeling between years , On 89-92 V6 the ECU plugs are labeled E, C and B where 93-95 are labeled A, B and C but that I know of all 3vz's used the same ECU with the only difference being MT or AT.

duck trapper

VooDoo,
Thank you so much for your input on this. This wire ID issue is no doubt the first of many,I will be encountering with this project. The mission I have chosen to except, is in a nut shell putting to good use major componants from my '91 3.0L manual SR5 pick up,( that I tipped over) into a tired, '94 4runrr-A/T. That had a bad motor in it, and the ECU,radiator, cruise control switches, power mirror switches,power antenna, and Lord knows what else robbed out of it before I bought it for 400US. So I have the pick ups ECU plugged into the 4 Rnnrs wiring harness. I havent dropped the motor in it yet. because I keep finding things that need to be done to it that are best done while the motor is out. So looks like I better locate a matching ECU to minimise all that heart burn. I had been hopeful That those units would be universal. I have compared the twos engine wirieing schematics and identified very little difference except as you pointed out that different circuits termanate at different pin locations. Soooooooooo.....An ECU from a 94,3.0 automatic ought to be a safe way to go here?
I was going to the fluids in the transmission and transfer case, but when I tried to loosen the drain on the tranny, but the plug just turns. That in its self isnt so big a deal, but it is likely the transmission hasnt seen any maintenance depending on how long the drain plug has been like that...
My plate keeps getting more piled on it, but I am having a pretty good time at it.Also the more I snoop around this here "yotatech" The more I lean towords trick mods as well as making a dead horse run again..
Thanks again VooDoo.
Respectfully, Duck Trapper