1. Clean throttle body...off the car. Sounds like you did that.
2. Reset TPS - you would need access to something with Jaguar specific software, like a PDU, WDS, etc.
3. Replace TPS - it is expensive, so I can understand reluctance to address, however your TPS is old. You will likely need a TPS reset at this time as well. Maybe worth it to cross both of these off at the same time?

This all assumes something is wrong. When I drive at about 52mph, it appears that my car also has a hiccup, as if the transmission doesn't know whether it should be shifting, so it seems like it's downshifting/upshifting/downshifting. I wonder what happens if you drive in Sport mode? That should change the shift points? Maybe I'll try that myself later today?

 

Hi Vee, thanx for your reply... the feeling you describe is exactly what i am experiencing.also feels a bit like one cilinder missing fire once in a while. but coils, cables and spark plugs have been replaced, and is very smooth in idle, even when its moisty. My issue only happens if theres no power asked, so when im driving on a flat road, without accelerating or driving off a hill. very noticable if i use cruise control (which is not the issue since it also happens without) at 100 km/h. if i have a passenger and some stuff in the back; this is not happening. probably because the engine needs some more pulling at those rpm's with some load on board, or the tps is at another position..Mine has the problem between 1800 an 2000 rpm. Since this is the most used speed; i can imagine the tps is the problem; i think it works with an old fashioned contact that moves over another contact. if the contact is at this same place a lot; say between 1800 and 2000 rpm i can imagine the contact is bad there. i did use some contact cleaner on the tps but it did not change anything at all. i recognized the tps a bit from a volume knob from those old radios... when it gets old and dirty, and when you move it the radio makes some loud noises. until you turn it a lot, or clean it. unfortunately, with the tps it did not help.

unfortunately, for me it was not the transmission not knowing what to do. driving in sports or 'economic' does not make any difference at all.


thanx, pim

 

You don't have an economy setting, the x1 just skips first gear.

Also, the TPS is sealed, so spraying it with anything is not going to do anything.

If you get a new TPS, then maybe it will resolve the issue, but for that kind of money, I would just ignore the issue. Keep in mind that if you ever think of replacing the TPS, be sure to come back here and ask what to do. If you can pull the voltage at idle with the TPS youre about to replace, it will probably save you the trouble of getting your TPS reset when you install the new one. You'll just have to install the new one and set it so that the voltages at idle are the same.

 

There are a number of good videos on YouTube explaining fuel trims much better than I can here.
Search and ye shall find.

 

Ignore the LTFT on your 95. Jaguar apparently couldn’t program something correctly and those values seem to “runaway”.

Typically it would help reveal if your car was being overfueled or underfueled to make up for a vacuum leak, wonky oxygen sensor, etc.

However Jaguar programmed the OBD2 computer to track this information wasn’t done correctly, hence it shows ridiculous values that don’t help anything.