My 96 XJ 4.0 4wd ~215k just started having issues shifting from 1st to 2nd when cold (~75F).. As soon as the temp gets up to 150 or so it shifts normally. I added a quart of Lucas' 'tranny fix' but no luck. Any ideas? How bad is it to drive on? Thanks!!

P.S. it's Automatic

 

What issue is it having? Waiting too long to shift to second? If so, does it shift if you take your foot off the gas momentarily?
How are the 2-3 and 3-4 shifts?
It's probably OK to drive as long as the shifts aren't mushy or slipping.... keeping in mind nobody here has actually seen or driven it, you'll have to use your judgment.

 

What's the fluid look like?

 

Radi,
What does it mean if it shifts better when you take your foot off the gas momentarily? I know it helps on mine (98XJ) but have been dealing with P0740 for several weeks now (separate thread so I won't get into details). I am just curious about your comment.
Thanks.

 

That might point to a TPS and/or TV cable adjustment problem, they are the only things telling the trans and TCU what the throttle is doing.
That P0740 (TCC lockup) may be related. Have you done anything with the TPS?

and:

 

Inspecting fluid level and adjusting the tv cable or my first suggestions. they say when adjusting the cable to push your foot all the way to the floor but i have found that i get better performance when i only apply 85% pedal travel before returning the pedal to the up position

 

Thank you. Yes, I changed the TPS because I had doubts, for a dealer unit. Things stayed the same. i adjusted the TV cable several times. The fluid was fine, and I still did a few drains/refills. Unplugging the TCU would still not allow to in 4th when shifting to D. It is at the trans shop who can't figure out the problem. They have changed the valve body, and now the NSS. Now the speedometer is jumpy in 1-2, only when cold. The trans behaves when warm.