I bought my XJ like a month ago. When I pick up, was functional perfect. I have to make some fixing on my new hobby so is on my garage making a floor overhaul and general maintenance. Now, I don't know why, when I put it on drive don't run with force; start like on second or third gear. If I lower the shifter down to first and second gear, start on first gear. Why this is happens? Why on drive isn't working well? Hope you guys can understand why I'm saying and can help me...

 

auto tranny right?

replace the TPS- throttle position sensor.

 

What year and which engine?

 

mine does this too, some do it as a mod. mine was like this when i bought it.
a buddy of mine was hooking up a taurus fan and accidentally shorted his out blowing a fusable link. after that, his started doing this.
you can first check the fuse in the harness to the transmission control unit. the tcu is located under the passenger side dash along the lower strip where the speakers are. if the fuse is ok, you can try swapping out the tcu. if that doesn't work, there's a problem somewhere. either a broken wire or blown link somewhere.
personally, i like mine for off road. it makes the tranny stay in first gear without automatically shifting into second while coasting down a steep hill.
but with that, i have no second gear at all. so when on the highway, when i shift into third, it skips second. kind of a pain, but i've been living with it for about 4 years now.
mind you, mine isn't my daily, so it doesn't see much around town driving. however i drive it 4-6 hours each way to wheel.
you just get used to it. it is now a semi-automatic.
you should start off in first gear so you don't burn out the bands tho.

 

It's an XJ 88 4.0L...

 

Try adjusting the TPS and see if that improves it. If not then you will need to replace it and properly calibrate the new one.

 

x2 on the TPS... or x3 not sure which.

The Renix models are pretty brain dead as far as electronics go. The only info the tranny and engine share is through the TPS or the NSS...

 

And where is located the TPS? Needs calibration or just plug and play?

 

It seems that my 91 Cherokee, with a 4.0 HO inline six cylinder, has an intermittent reverse gear.
Every other gear works perfectly fine, we did a flush and transmission filter change 3/17/09. One day the reverse gear stopped engaging. Although it seems from the sound it is engaging in the transmission, most of the time i can floor the accelerator and no movement other than just a slow roll. Sometimes it engages and i have reverse but, it doesn't have all the power it had before this problem arose. Any ideas as to what is causing this? And what exactly is a TPS? Could this be a problem?