80 series bad idle, sluggish acceleration when cold

[DeliBoyCreates]

I would buy oem O2 sensors and relocate them to the manifold. That sorted out rough running and codes in my wife’s 94.

Leave the current bungs in place and pull the connectors into the engine bay. Wrap the wiring in heat/fire proof wrap, install the new oem sensors.

The relocation requires delete of the PAIR system. So, if you have yearly smog, this probably won’t work for you.

If my other diagnosis do not work I will be heading down this route.

 

[DeliBoyCreates]

Only one of the oem sensors for the ‘94 is still available. I can’t recall if it was the long or short one. But Toyota still has them. When I relocated the sensors to the manifold (recently), I used the oem sensors and that still available x2.

The two new ones I put in (part number 89465-69115) are not OEM/compatible? Would hate to toss more money on parts until I check out the other tips in the discussion.

 

[effjay80]

You good!

 

[Old Nick]

The two new ones I put in (part number 89465-69115) are not OEM/compatible? Would hate to toss more money on parts until I check out the other tips in the discussion.

Absolutely get that. Firing the parts cannon willy nilly isn’t advisable. BUT, if your issue ends up being related to the O2 sensors, I would stick with OEM. I’ve read of too many failures where aftermarket sensors are concerned. They (oem sensors) are still out there and available.

 

[DeliBoyCreates]

I think I have honed in on the issue. The connection wires for the O2 sensor are as shows, open wires frayed. Next question would be does anyone know where to get a new set of wires/connection?

 

[Old Nick]

I think I have honed in on the issue. The connection wires for the O2 sensor are as shows, open wires frayed. Next question would be does anyone know where to get a new set of wires/connection? View attachment 3845571View attachment 3845572

I poked around a little, and found this thread... it covers that wiring (just scroll down a bit on the first page and you'll see the diagrams):

Wire to bank 1 O2 sensor corrupt 1994 FZJ80 help pleas

forum.ih8mud.com

If only one of the wires is frayed, I would strip back the covering, solder in new wire and heat shrink a new cover on to it. Those wires have quite a bit of "play".

 

[DeliBoyCreates]

I poked around a little, and found this thread... it covers that wiring (just scroll down a bit on the first page and you'll see the diagrams):

Wire to bank 1 O2 sensor corrupt 1994 FZJ80 help pleas

forum.ih8mud.com

If only one of the wires is frayed, I would strip back the covering, solder in new wire and heat shrink a new cover on to it. Those wires have quite a bit of "play".

That sounds like the better idea! Thanks!

 

[Kabanstva]

I think I have honed in on the issue. The connection wires for the O2 sensor are as shows, open wires frayed. Next question would be does anyone know where to get a new set of wires/connection? View attachment 3845571View attachment 3845572

Which 02 sensor has these damaged wires? Curious how that could have happened?

 

[TheBussman]

I think I have honed in on the issue. The connection wires for the O2 sensor are as shows, open wires frayed. Next question would be does anyone know where to get a new set of wires/connection?

look on the plastic housing for the connector number, seach for it in the wiring repair manual listed in the resources section of this forum and then find the corresponding repair wire to order from your dealer. or try Ballenger motorsport

 

[efjayatee]

How did you clean the MAF and IAC?

Did you replace (or forget) the gasket for the EGR valve (and Throttle Body if that was removed), new O-ring for the IAC valve? Any of those
could cause an air leak.

If you have or can buy a scan tool, even a cheapo, you can look at a few parameters including the ECT sensor temp readout.
Edit: the OP's 80 is a 94 model (OBD 1, missed that) so you can use a scan tool that is designed to work on Toyota OBD 1 vehicles.
Search you tube or Amazon for OBD 1 scan/scanner/diagnostic tool

It's called TOYOBD1, but does not read engine codes

OBD1 Scantools

zf-scantools.com

 

[DeliBoyCreates]

Which 02 sensor has these damaged wires? Curious how that could have happened?

On the sensor closer to the driver side, I had a similar thought as to how it could have happened. The covering over the wires has fell apart so I’m assuming a rock or some sort of debris whacked it good.

 

[DeliBoyCreates]

On the sensor closer to the driver side, I had a similar thought as to how it could have happened. The covering over the wires has fell apart so I’m assuming a rock or some sort of debris whacked it good.

look on the plastic housing for the connector number, seach for it in the wiring repair manual listed in the resources section of this forum and then find the corresponding repair wire to order from your dealer. or try Ballenger motorsport

Copy that, I ordered a whole new connection housing and wires due to how rough it’s looking.

 

[sp4]

Just following up on the fix for my original issue!
I bought oem o2 sensors from toyota, they only had the passenger side sensor available so I bought two of them. after replacing them the idle issue is fully resolved.

 

[petegangies]

Just following up on the fix for my original issue!
I bought oem o2 sensors from toyota, they only had the passenger side sensor available so I bought two of them. after replacing them the idle issue is fully resolved.

Excellent news!

 

[DeliBoyCreates]

Quick update, I replaced the connection housing and the troubled O2 sensor and the truck is running perfect again. Thanks everyone for the helpful advice!

 

[Mat Jadamec]

I would double check your O2 sensors. I went through 2 sets of Denso 95 spec an NTK that was supposed to be for a 93-94 and it still ran poorly. I ended up buying NTK sensors off Amazon that fixed my problem. Check the O2 sensor voltages and make sure they are switching properly.

just wanted to add 2 NTK 24080 o2 sensors worked for me. Plug and play. I had a code 21 with awful misfire and sluggish accel that was getting worse. The CEL went away after replacing the forward one. It still ran poor so replaced aft one as well. Now it runs better than I can remember. I also have them in the PAIR ports and still have a stock EGR set up