1993 transmission acting up (throws out of gear, lost reverse, starting in higher gear)

[Drilldeeper]

When you say it threw you out of gear…did you mean it shifted unexpectedly? You were in D? You need to check the NSS connectors. They are hard to get to, but important to rule out.

Yes I was in D and stepped on the gas and it threw me out of gear, the revs went up. Yes, the connector is the next thing despite of the fact that the PO had already looked at it and cleaned/reconnected it. Thanks!!

 

[PNWTreeOctopus]

Yes I was in D and stepped on the gas and it threw me out of gear, the revs went up. Yes, the connector is the next thing despite of the fact that the PO had already looked at it and cleaned/reconnected it. Thanks!!

Yep, I’d certainly use the FSM continuity guide to check it, despite PO inspections.

Post #1 makes it sound like the PO opened up the NSS connectors (there are 2) cleaned them up and used some electrical tape to fix something. That’s where I would start. When I opened mine up and cleaned things, the pins started falling apart on both of the front of the connector and the back. I cleaned up my corrosion and it didn’t solve my issues since the breaks were hidden behind the plugs and some of the female pins had corroded away. Here’s a before and after cleaning photo:

I thought it was golden when I clean it up, but i didn’t check the continuity and wasted a bunch of time. Ultimately I discovered a wire that had broken from a pin behind the connector so I cut it out and used an aftermarket connector.

Keep being persistent and get that FSM and electrical supplement, you won’t regret the purchase.

 

[Drilldeeper]

Yep, I’d certainly use the FSM continuity guide to check it, despite PO inspections.

Post #1 makes it sound like the PO opened up the NSS connectors (there are 2) cleaned them up and used some electrical tape to fix something. That’s where I would start. When I opened mine up and cleaned things, the pins started falling apart on both of the front of the connector and the back. I cleaned up my corrosion and it didn’t solve my issues since the breaks were hidden behind the plugs and some of the female pins had corroded away. Here’s a before and after cleaning photo:View attachment 2920978View attachment 2920977
I thought it was golden when I clean it up, but i didn’t check the continuity and wasted a bunch of time. Ultimately I discovered a wire that had broken from a pin behind the connector so I cut it out and used an aftermarket connector.

Keep being persistent and get that FSM and electrical supplement, you won’t regret the purchase.

Thanks! What's FSM again?

 

[PNWTreeOctopus]

Factory service Manual.

The 80 series FAQ has a helpful list of the various Acronyms used on mud. The FSM itself has a page or two dedicated to this as well.

eBay has reasonable prices on physical manuals, but they are free in the resource tab here on iH8mud. I’m not sure about the 1993 EWD (electrical wiring diagram) suplimebt for the 93 though.

 

[use2bn83]

This was mine....

 

[Malleus]

FWIW, there's no reason to throw the OEM connector housing away, just because the terminals inside are corroded. The Wiring Harness Repair manual has very clear step by step instructions detailing how to remove and replace terminals. You can get new ones for less than pennies each from Newark or Ballenger Motorsports.

Also, the harness side connector housings are still available, you just have to look for them. You can get new, complete, engine harnesses, which can't be made without them.

The Wiring Harness Repair manual is also available, for free, in the Resources section.

 

[PNWTreeOctopus]

FWIW, there's no reason to throw the OEM connector housing away, just because the terminals inside are corroded. The Wiring Harness Repair manual has very clear step by step instructions detailing how to remove and replace terminals. You can get new ones for less than pennies each from Newark or Ballenger Motorsports.

Also, the harness side connector housings are still available, you just have to look for them. You can get new, complete, engine harnesses, which can't be made without them.

The Wiring Harness Repair manual is also available, for free, in the Resources section.

Those resources you’ve put in the resource section are fantastic. Thank you @Malleus!

 

[PNWTreeOctopus]

This was mine....View attachment 2921351View attachment 2921352

These photos represent very well what can lurk in these connectors. They look like they have coolent flavored greasy mud.

I’m dying to know what the OP’s look like.

 

[Malleus]

Every one I've pulled apart has been full of coolant inspired corrosion. Since you cannot (unless your arms are pipecleaners and your hands are the size of a 2 year old's) reach that little hose on the block the lower end of heater tube is connected to, I am baffled as to why Toyota ran a metal tube most of the way to the block and connected it with a rubber hose. I guess you could make the argument that the strain on the block connection could be a failure point, but it's no worse than the hose/tube connection currently is. And the failure mode and effect wouldn't be any different. I may fab one up, just for Ss & Gs.

Or find a condom for the connector housings.

 

[use2bn83]

FWIW, there's no reason to throw the OEM connector housing away, just because the terminals inside are corroded. The Wiring Harness Repair manual has very clear step by step instructions detailing how to remove and replace terminals. You can get new ones for less than pennies each from Newark or Ballenger Motorsports.

Also, the harness side connector housings are still available, you just have to look for them. You can get new, complete, engine harnesses, which can't be made without them.

The Wiring Harness Repair manual is also available, for free, in the Resources section.

Man I’ve search everywhere and called all of the usual suspects. I could not find a new early harnes or the engine side connector anywhere. I did end up repairing, but if you have a source, please share I’d pay $1000 for a new early engine harness.

 

[Drilldeeper]

Man I’ve search everywhere and called all of the usual suspects. I could not find a new early harnes or the engine side connector anywhere. I did end up repairing, but if you have a source, please share I’d pay $1000 for a new early engine harness.

I sure will. For now I'm going to lose some weight so my hands get smaller so I can get to the old connector

 

[Malleus]

Man I’ve search everywhere and called all of the usual suspects. I could not find a new early harnes or the engine side connector anywhere. I did end up repairing, but if you have a source, please share I’d pay $1000 for a new early engine harness.

I was referring to the engine/transmission connector being available, IDK about the '93/'94 harnesses.

The connector housing is EC1; it's tough to locate, because it's not on any of the wiring diagrams, it's on the routing diagram, because it's considered a connector between the engine harness and transmission harness:

90080-11087 (engine side) (which is available from Toyota):

and 90980-11086 (transmission side) (which is not available form Toyota):

the terminals are (2.3 Type II):

 

[Malleus]

So, to remove/replace the terminal (this is an F type housing):

The terminals themselves are not waterproof. The same 2.3 Type II terminals are used in the waterproof and non-waterproof housings. What makes the housing waterproof is the little O-rings on the wire, just behind (or outside of) the terminal. Ballenger has (or can get) the terminals (and maybe Newark or Mauser, I haven't checked lately) and a tool to crimp them with; I highly recommend the tool. It's not expensive ($10 or $20), and if you're going to the trouble to open the housing and clean and/or replace the terminals, you might as well do the job right/once. You'll also need Joey's tool; or you need to make your own (I use a pick, but his is cool).

I haven't looked for the transmission side connector, but Ballenger may be able to get that; you'd have to call them. It's a Sumitomo.

FWIW, all this info is in the Wiring Harness Repair Manual, in the Resources section. It was a happy coincidence that you posted this, I'm doing this very clean-up/repair on my son's 80 while the head's out for headgasket R&R, so I needed to dig this out anyway.

 

[Drilldeeper]

I was referring to the engine/transmission connector being available, IDK about the '93/'94 harnesses.

The connector housing is EC1; it's tough to locate, because it's not on any of the wiring diagrams, it's on the routing diagram, because it's considered a connector between the engine harness and transmission harness:
View attachment 2922293

View attachment 2922294

90080-11087 (engine side) (which is available from Toyota):
View attachment 2922296
and 90980-11086 (transmission side) (which is not available form Toyota):
View attachment 2922297

the terminals are (2.3 Type II):
View attachment 2922299

Thank you!!

 

[PNWTreeOctopus]

Did it ever warm up where you live? How's the troubleshooting coming?

 

[Drilldeeper]

Did it ever warm up where you live? How's the troubleshooting coming?

It's hot here already, humid like crazy. No, I haven't done much to it yet. I did clean the NSS. Oh, I did play with the kick-down cable adjustment, it seemed loose. It drove perfect for 20 minutes and I thought I fixed it. But then it got to the temperature I guess and it started doing the same thing, the first throw-out starts with the third gear, then it's a mess. I still have 1 and 2 if I switch to 2. Then I noticed OD light flicker a couple times. That's the first time I see it do it.
Still need to pick a day to try to get to the connector.
I ran into the PO today, I mentioned the OD flicker and he immediately said, "it threw you a code!". It was more like a bad electrical connection kind of flicker... Not sure.

 

[gummycarbs]

I mentioned the OD flicker and he immediately said, "it threw you a code!". It was more like a bad electrical connection kind of flicker... Not sure.

I believe that when there's a transmission error, the O/D light blinks at a steady rate. You have to jump connections in the OBD port to get it to blink out the actual error code(s). Also, if you have overdrive turned off, the O/D light will be on steadily, even if there are error codes to be read.

This is from my '94 manual:

 

[Drilldeeper]

I believe that when there's a transmission error, the O/D light blinks at a steady rate. You have to jump connections in the OBD port to get it to blink out the actual error code(s). Also, if you have overdrive turned off, the O/D light will be on steadily, even if there are error codes to be read.

This is from my '94 manual:

View attachment 2934184

That's what thought too. The way it flickered was very hesitant

 

[Drilldeeper]

I believe that when there's a transmission error, the O/D light blinks at a steady rate. You have to jump connections in the OBD port to get it to blink out the actual error code(s). Also, if you have overdrive turned off, the O/D light will be on steadily, even if there are error codes to be read.

This is from my '94 manual:

View attachment 2934184

And thank you for the scans!!

 

[gummycarbs]

And thank you for the scans!!

They're from the PDF version of the factory Service Manual. If you don't have it already, find it and download it.