Wire to bank 1 O2 sensor corrupt 1994 FZJ80 help pleas (1 Viewer)

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I read TIS FSM I have I used Search I cannot understand which wire connects to Bank 1 ?

Is it engine wire 82121-60342?

I fixed this 3 times already it works for a few mounts and then again it failed

I am wondering if it is possible to take it out form rig and put it on the table to renew it it is very difficult to do this on the lift under the car

better yet i would bay new one but I know this part is discontinued

I ordered connectors from people here on MUD that part out rigs but the connectors and wires i received where old and in miserable condition

Your advice needed
 
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I ordered connectors from people here on MUD that part out rigs but the connectors and wires i received where old and in miserable condition

Below you'll find a link to a factory wiring harness service manual that i think may be helpful. In the later sections of this manual you'll find a complete list of wiring harness connectors showing their shape, the number of pins they use, along with the factory part number for each connector.

 
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Thank you @Rifleman for your saport

I am struggling with this wire harness from the day I got the rig
Fixed it 3 times do you know if I can remove the harness without having to pull the engine or major components out? Renovate it?

Friday after I worked very hard preparing smoked meat gathering firewood to go with wife and friends to hot springs in the Death sea I start the rig and get the check engine I drove anyway withe poor power and bad idle

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richardlillard1

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The 93-94 models have what I would call odd wiring arrangement. The o2 sensors are definitely part of the main engine harness, but one of them ties into the main harness near the diagnostic port, the other branches off in the splice point after it’s beneath the intake manifold. These are H7 and H8 in the wiring routing diagram below. If it’s H7, one possibility could be an issue where the harness passes by the EGR. This typically causes misfire issues (cylinders 3 and 4 are the most common I’ve seen), but could cause issues with the o2 if those wires have suffered any damage.

Since you can fix it down near the sensor, but the problem persists, I would instead check the wiring closer to the sensors themselves. If it is too close to the exhaust, the wires and/or connectors will have signs of heat damage.

Another possibility, if it’s H7 would be where it goes over the transmission. I’ve seen the wiring have issues on other 80s, usually the CDL wiring, where it starts to ground itself on the transmission and cause various CDL issues.
BBF544E5-990D-40D1-AC2C-1B1EB1291AC1.jpeg
 

richardlillard1

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Thank you @Rifleman for your saport

I am struggling with this wire harness from the day I got the rig
Fixed it 3 times do you know if I can remove the harness without having to pull the engine or major components out? Renovate it?

Friday after I worked very hard preparing smoked meat gathering firewood to go with wife and friends to hot springs in the Death sea I start the rig and get the check engine I drove anyway withe poor power and bad idle

View attachment 2504186View attachment 2504187
View attachment 2504188View attachment 2504189

The wiring harness can be removed without pulling much. We’ve done a few OBD II trucks now and I believe the only thing we move out of the way is the throttle body, in which case the cooling system needs to be drained. The driver’s side of the two 1FZ 80s is pretty similar, so it should be the same for yours.
 
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my
The 93-94 models have what I would call odd wiring arrangement. The o2 sensors are definitely part of the main engine harness, but one of them ties into the main harness near the diagnostic port, the other branches off in the splice point after it’s beneath the intake manifold. These are H7 and H8 in the wiring routing diagram below. If it’s H7, one possibility could be an issue where the harness passes by the EGR.
This typically causes misfire issues (cylinders 3 and 4 are the most common I’ve seen), but could cause issues with the o2 if those wires have suffered any damage.

Since you can fix it down near the sensor, but the problem persists, I would instead check the wiring closer to the sensors themselves. If it is too close to the exhaust, the wires and/or connectors will have signs of heat damage.

Another possibility, if it’s H7 would be where it goes over the transmission. I’ve seen the wiring have issues on other 80s, usually the CDL wiring, where it starts to ground itself on the transmission and cause various CDL issues.


Thank you for your help

Fortunately, my problem is H8 connector and wires near it when I got the rig the car side connector was broken I ordered used connector with pig tail from @slow95z he helped me to fix the problem but to install it I had to cut the original one and waterproofing is an issue

I removed PAIR and EGR as part of baseline I am going to move the O2 sensors to the PAIR position

Ordered new connector, but they are almost the same just almost

126925061_291335575539434_2705450402797411149_n.jpg
 
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richardlillard1

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my



Thank you for your help

fortunatly my problem is H8 connector and wires neer it when i got the rig thecar side conector was broken i orderd used conector with pig tail from @slow95z he helped me to fix the problem but to install it i had to cut the original one and water profing is an issue

I removed PAIR and EGR as part of baselining i am going to move the O2 sensors to the PAIR position

Waterproofing the connectors is a bit easier to deal with. A set of these crispers:

Amazon product
And a set of terminals and waterproof boots from here:


These have worked well for me. The engineer pliers can reproduce the factory crimps quite nicely and the terminals fit great. I’ve even had success with ordering just the non-waterproof terminals, then taking my time to crimp the boots into place, which seems to work the same from what I can tell.
 
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Below you'll find a link to a factory wiring harness service manual that i think may be helpful. In the later sections of this manual you'll find a complete list of wiring harness connectors showing their shape, the number of pins they use, along with the factory part number for each connector.



@Rifleman Is this link for 1994 obd1 rig? The connector is not the OEM one that is installed on my rig see pic above
 

richardlillard1

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@Rifleman Is this link for 1994 obd1 rig? The connector is not the OEM one that is installed on my rig see pic above

That manual is universal to all Toyota’s of the period. It’s in there somewhere.

To make things easier, look for the number on the connector itself and add the prefix 90980- to get the part number for the exact connector needed.
 
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Waterproofing the connectors is a bit easier to deal with. A set of these crispers:

Amazon product
And a set of terminals and waterproof boots from here:


These have worked well for me. The engineer pliers can reproduce the factory crimps quite nicely and the terminals fit great. I’ve even had success with ordering just the non-waterproof terminals, then taking my time to crimp the boots into place, which seems to work the same from what I can tell.


Can't see the Amazon link it inserted it as media
 
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That manual is universal to all Toyota’s of the period. It’s in there somewhere.

To make things easier, look for the number on the connector itself and add the prefix 90980- to get the part number for the exact connector needed.


no number on them
 
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@Rifleman Is this link for 1994 obd1 rig? The connector is not the OEM one that is installed on my rig see pic above

Take a look at the connector on page D-13, third row down, first connector on the left, it looks like a match for the old ones in your photo. Part number for that connector is 90980-11178.
 

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