I have a 1990 RENIX Jeep. I've had a problem with it running rough in gears other than 1. You can read all about it on my other thread here
https://www.cherokeeforum.com/f2/engine-cuts-out-70084/

I have noticed it will run right for awhile if I twist these two wires together. They come down in the harness with this other sensor wire. You can see the two sensors (speed sensors I think) arrowed in the photo. The danglers are a yellow wire with black stripe and a black one with red stripe. Anybody that can tell me what the fark these are and where to attach them gets a free beer on me
Also, if I touch my battery terminals together it will run good for a short while. It seems apparent these are some sort of feedback to the ECU, but I see nothing they can connect to. The trans is an AW4 that was rebuilt last January. I don't actually know if it's the original for the Jeep or a different rebuilt unit they tossed in there. If I unplug the TCU it runs great in 1, like a turd in 3 or D. Basically the same thing as with the TCU connected. The Power/Comfort switch IS working. I am hoping someone knows exactly what I need to do to resolve this issue.

 

This isn't part of your issue but you need to fix that missing vent hose to save future issues. Those two wires could possibly be for the 4wd light switch?

 

I sure hope someone has more useful input than this...

 

I apologize for trying to help. Won't happen again.

 

actually I was just trying to bump the thread. I appreciate any and all input, since I honestly am stumped on this one. I am pretty sure the part-time and 4x4 lights are vacuum operated, and I'm not overly concerned about the vent line just now. I meant no offense. Come down to SoCal I'll still buy you a beer

 

Its ok. Ill try to remember to check a wiring diagram out for you tomoro when im at my shop.

 

I looked up a wiring diagram. I didnt see any wires of those colors but ill keep checking and see what I can find for you.

 

here are some of them answered

 

quick thought...do you have power to the TCU? There is a fuse for the TCU hidden behind the passenger side kick panel.

 

The reason your Jeep is sluggish in 3 and D when you disconnect the TCU is because disconnecting the TCU takes away your tranny's ability to think so it will not shift automatically. It will however go straight into whatever gear you select with your shifter so taking off from a stop in 1-2 obviously works great but taking taking off from a stop in 3 or D is too high of a gear think of it as trying to take off from a stop in 3rd or 4th gear of a 4-speed manual tranny. You can drive your Jeep without the TCU connected but you will have to always manually shift it through the gears.

 

I meant with the TCU disconnected.

 

you got a pm

 

one wire could also be the back-up light switch?

 

I didn't attempt to start from a stop in 3 or D. Drove it like a stick, more or less. Thing is I get the stumbling whether or not the TCU is plugged in, however it does shift correctly on it's own. I am thinking I need to take another look at the TPS. And spark check, and whatever else I can think of. It seemed like there was a direct correlation between running crappy and being in 3 or OD. And it also seemed like twisting these wires together made it better temporarily. But now I am wondering if that was just my imagination, since I now get a dead spot when I punch it from a stop where before it would accelerate very smoothly until the shift. Unless the fuel pump is failing, or the coil is bad. TPS ground might be bad.

 

What should I do about that vent anyway? It looks sort of....bent