Clean your TPS, I was having the same issue. Cleaned it and its been fine for over 2 years now.

 

Damn, I just dropped it off at a Jag Specialist shop. They are backed up for a week. I may hop over there with a 10mm socket and some screwdrivers to pull the throttle body and clean it up.

I have to say that I installed an oil catch can years ago to keep that throttle potentiometer (and butterfly plate) clean. I haven't seen much gunk in there at all since.

 

Its not the throttle body itself that gets gunked up, its the TPS. It sits below the Throttle body in which it will catch the oil that you dont see inside the throttle body. What I did was drill two small holes inside the red TPS cove at the very bottom. This way I can insert the straw end of a throttle cleaner spray. Squirt some cleaner in one hole and watch the oil and gunk come out the other end, drown it until the fluid flows out clear. The holes should help alleviate the amount of oil that could potentially accumulate in the future too. Its a very common issue in our cars, and I prefer this method to removing the throttle or the TPS.

 

Brewtech, you must have a 1993 or older with the TPS with the red plastic cover? The newer TPS have no place to drill any holes.

Im using JLM12074

 

Ah yess. Totally different part. The only I can think of is that the TPS is failing. Have it checked out. If the throttle doesnt get the correct readings, it will throw the car into limp mode, which involves the transmission. Although the transmission isn’t at fault here.

 

You are right, that the TPS can cause all sorts of havoc. I feel dumb that I didn’t swap it out with an old one that I still have. I did replace it with an OEM part about 5 years and 40,000 miles ago.

 

What’s the good word mate?

 

Well, I got a call from the Jag shop. They told me that everything seemed to check out ok and that they had a spare transmission valve body from a 97 XJ6 that they could put in there. They said it’d cost about the same to swap out just the solenoid, but it would be a safer bet to just swap out the entire valve body.

I greenlit that work. Parts and labor to be around $1,000….

 

Great! Lets hope that’s it, and theyre not throwing parts at it

 

Apparently replacing the valve body, in its entirety, resolved the problem.

I am taking the old one back with me. Based on all the research I’ve done in my spare time waiting for the car, it seems likely that a plastic ball bearing may have broken up, or perhaps the solenoid truly has failed….either way, I’ll have a spare on me and see if I can’t refurbish it….carefully.

$260 in parts, 5.7 hours for replacement and diagnosis.

 

This is good news! Glad its back on the road

 

So I have that valve body on my table. I tested the solenoid, while still connected to the valve body, using the end of the harness. Clicked away when I showed it some 12v action.

Is there any other way to test a solenoid?

The car is running perfectly with the replacement valve body from the 97 XJ6, no cause for alarm, just figured I'd see if I can tell what went wrong.

 

The ZF forums are more informative in regards to these transmissions I believe.