My throttle became sticky recently so I've decided to clean it today, as this was never done on this car. It turned out to be a rather major job as the TB was super dirty and of course both IACV little bolts snapped while undoing them.
Lots of scrubbing and even a little 800 sanding was required but got there eventually, its clean now and works great.
While there I've noticed few things. It seems there are two holes where the throttle cable is bolted, M and A. I suspect this is for Manual and Auto. Mine is mounted in M even though its Auto. Should I move it to A?
I've decided to replace the throttle spring as its still available from Jaguar and when I replaced it I've noticed the spring just doesn't sit right, there is 5mm+ gap between the spring seat and the top part of the TB. I've put a large nut in there but I'm wondering whether there suppose to be some sort of an extra spacer there that I'm missing(pic of the nut attached).
Last thing, I've noticed a lot of oily residue in the intake(too much), already ordered oil breather kit as its clearly a must for this engine but I was wondering whether something like sea foam would help cleaning the intake a bit or is it intake out job? I have to replace the intake gasket at some point so might do it eventually anyway.

Oh, and for all people with a high idle issue, the attached pic shows TPS sensor. Despite the looks, IT IS possible to adjust this by maybe a 1mm each side with loosened screws. This is almost always enough to get the idle back to normal. Ideally this is done from underneath the car while its running so you can find the correct position when TB is closed and then tighten the TPS.
This may save you a visit to Jag dealer to get this set up in WDS.

 

That throttle body cleaned up very well. A couple of the Jaguars I have had also had the throttle cable in the wrong hole in the bracket, I moved mine to the A position.

Make sure you adjust the throttle cable so it moves the throttle plate all the way open when you floor the accelerator pedal. A lot of these cars seem to have this problem. You cannot get the maximum power out of the engine if you cannot have wide open throttle.

 

With the key in the run position before starting you will have power through the TPS . The Green / Yellow wire should read 0.60 + or - 0.02 volts . You can shave off some of the wire insulation as it goes over the fuel rail and tape it up later . You can easier adjust the TPS sensor in your hand before installing the TB assembly . Mine was at 0.63 volts for whatever reason and drilled the TPS plastic mounting holes up a size to put my TPS right on 0.60 volts .

The TPS sensor reading at butterfly closed position is orientated or matched to the ECU and if you get them to match at the last orientation you should be good . The TPS sensor can be adjusted from the top while the whole TB assembly is installed but takes some patients .

The IAC valve bolts are loctited in so some heat and penetrating oil may help .

As to the gap on top as the new spring is installed I don't see that there would be a problem in how the spring functions

Remove and clean the inlet air temp sensor in the plastic 90 degree bend as this will be gucked up as well

If you remove the intake manifold the critical area to clean is the ports on the head so it flows better .

 

Issue with the spring is that without that large nut(spacer) I've added, the top spring seat can(and will) move up and down and if its fully up, the spring just comes out of it, bends sideways and sits distorted and doesn't work as intended.
Plastic elbow already cleaned, it was bad too, hence me ordering that oil breather kit, clearly a good idea for these cars

 

Turns out I had this issue too. It appears my throttle cable is stretched too far now, I have it adjusted all the way up and I can still get up to 4.75V at the TPS with the pedal floored.

Another thing I've noticed, even with the new bottom spring the throttle would stick with the cable adjusted to max. To fix this, both top two springs needs to be adjusted by one extra turn each. Just pop the end of the spring out of the hole, add extra turn and that's it, now throttle open and closes perfectly.

Even at 95% max, the car drives like new. I've put the cable in Auto mount, but I might switch it back to M again as this should give me an extra mm or two of adjustment, should be enough to pull it to 100% TPS at wide open throttle

 

Very useful information. Thanks for sharing

 

Katar83, I am too lazy to go down to my garage and check this on my car but; Do you really expect 100% TPS reading? Obviously we do want to be sure the throttle is mechanically fully open. The TPS is just a variable resistor and even at WOT we don't want it to be off the end of the resistor material, close but a little bit left. So does this mechanically WOT give us 100% TPS? Or say 95%?
Same at the idle end; even when the throttle is mechanically fully shut the TPS must have a little bit of resistor track left. Does this mean we cannot get a reading below say, 5%, for example?

 

Not exactly 100%, but would be great to get it as close to it as possible. Currently on kickdown it will go up to 4.75V max, I'd like to get it to 4.9V(out of 5) so ~98%.
At idle it goes down to 0.57V and that's crucial because only then the IACV will work.

Before adjusting the cable, the max I could get was ~4V and I could feel it became sluggish. Car runs amazing now, best since I bought it for sure.

 

Hi, regarding the A Auto and M Manual locations, can you please clarify what you mean by "While there I've noticed few things. It seems there are two holes where the throttle cable is bolted, M and A. I suspect this is for Manual and Auto. Mine is mounted in M even though its Auto. Should I move it to A?"
Do you mean where the cable housing adjustable nuts are mounted to its bracket as shown in the pic I've attached? Where are the A and M marked?

 

They are on the right, windscreen side of that bracket, as far as I remember.