Alejandro,
I agree with what the guys have said already, but would offer a couple of suggestions.
Firstly, TPS issues do not usually involve transmission issues. You said your gearshifts were harsh, so you definitely seem to have the transmission in limp mode. I would be inclined to get to the bottom of this first before focussing on the idle speed issue. As has already been suggested, retrace your steps and check everything has been reconnected correctly. Have you tried clearing the codes with your scanner? They do not clear automatically, and once the gearbox light is on, you are in limp mode, even if the original fault has been fixed.
The TPS issue does not throw a code or a warning light. You will need to look at "live data" with your scanner. Throttle position as mentioned, and also coolant temperature. I had experience of a faulty coolant sensor which was telling the ECU an extreme temperature reading which caused the idle to be raised. Easy fix.
You also mentioned you had loosened off the throttle cable, to no effect. Are you remembering that there are two parts to the throttle cable, both of which need to be correctly adjusted, before and after the traction control / throttle relaxer?

 

Live sensor value data with a ELM - 327 will let you see where you're at

You can see it in the form of a recorded graph after a test drive later at home or on this forum

There was a good Youtube video on this I can't find now

The TPS will not read lower then 11 or 13 % at idle closed position

The Mass air flow rate as a rule of thumb will be around 1.0 grams per second for each 1.0 liter displacement at 650 RPM

The correct RPM is 700 and you are pumping in extra air so you may be around 5.0 grams per second

There is a software error in the ELM - 327 devise so you may have to multiply the given MAF value by a factor of 10 or 100 to make sense

 

unreliable TPS data will confuse the transmission and eventually damage it.

the TH400 had a vacuum modulator and electric kickdown switch, the 4L80E replaced that with electronic sensor control. it needs accurate crank sensor and TPS data to work right

 

The crankshaft sensor on the X300 seems to go bad in some aspects of it's usage around the car without telling you

There was a resent example of one going bad in one aspect ( fuel pump enable ) but was able to see a corresponding error in the difference in starter rotation speed of 200 RPM vs. 300 RPM

Someone found the CKPS wiring splice inside the bundle going over the fuel rail had deteriorated

Some have just simply cleaned the face of the sensor of debris effecting the signal

The connector is always suspect given the environment it is in

 

Thanks for all your support. After the break, I have the dates from the TPS and the sensor it seems to be ok.


Rev on the upper graphic and butterfly opening percentage on the downer graphic.


The screen shot showed the real info about rpms, MAF sensor also the oxygen on lambda sensors.


As you could see on the pictures below, the info sowed by the car scanner app it seems to be ok. I have something to add to the fault information.

I had read the P0753 which means that the circuit A is open or malfunction.

Other problem that I see with the instant information from ECU is that the butterfly is open when de revs increase (leaving the accelerator pedal free).

Someone tell on as on the response above that there are two springs for the butterfly return, how can I be able to adjust those springs? In addiction I have to say that the butterfly cannot be closed by hand when the car is revving (it is clase at all)

I hope this new information so us the way to understand the problem I help us to find the solution

Thanks in advance for your replies

 

Dear all,
I have tried to solve the problem again and now I can say that the gearbox problem is related with the P0753 solenoid A malfunction. I think that this malfunction is due to the inestable idle and this high revs affected to the gearbox and broke the actuator or something.
Other things I will like to ask you is if someone has a problem with the Traction Control. I think that it has a problem too. The two cables that came from the bottom side to into the actuator are in bad condition (the cable cover is out) and the actuator is also communicated.

Could the cables be connected between them?

I also confirm that the cables are also be connected inside the traction control actuator.

It is normal or I should change this device. Could this problem affect to the idle problem?


Thanks all in advance
Additional information will be appreciated

 

You have what I have on the bottom of the TC actuator , some have put shrink wrap on the exposed wires

By turning off the TC you would think the TC actuator is not biasing the idle setting on the throttle cable

Have you checked the connector on the left aft attached to the transmission body

The connector has a trick and does not just twist off

 

You subject to put shrink wrap on the cables because they are not okay (I will put it this evening)

I think that the TC is opening the throttle butterfly, the cable or maybe the TC actuator is stuck due to exposes wires. Don't you think?

Thanks for your comment Parker 7

 

The role of the TC is to retract or more close the butterfly

The neutral or resting position of the TC actuator may be off and is subject to someone else right now

C1495 TC actuator - Jaguar Forums - Jaguar Enthusiasts Forum

Your TPS on idle stop should be 11 or 13 % and never gets to 0

The mass air flow at the proper idle speed is a little over 4.0 gram / second and is sometimes a error in the reader and would be a multiplication factor of 10 or 100 to correct

See page 90

www.jagrepair.com/images/Training Guides/801S - 2000.pdf

It will read 1.2 volts DC on the center wire of the MAF sensor connector still installed

Short term fuel trim has a target of 0.0 but is not perfect at all times

Your engine coolant is above 88 C so you are in closed loop mode

 

I'll review your readings in the morning

 

Might be worth a check to see that the TC is correctly adjusted as well. I can not remember who posted these first, but thank you as I have found them very useful!

 

I'm stealing that for another post

 

My opinion is to leave the TC actuator alone for now and just unplug it or turn it off

Could be adding a mis adjusted component into the engine regulation system ( opening up a can of worms )

 

Hello again
I have tested the idle with and without the TC and there was no diferencies at the engine revs. Also I have disconnected the IAC and there was no changes. I have readjust the throttle cable to the pedal and throttle body which allow the engine slow down the revs from 1200 to 800. That is okay. But I have still experiencing the high and fluctuating revs.

I have noticed the revs going down when I select R or D on the gearbox. So the fluctuating revs maybe only happened when Parking or Neutral are selected. Also when I move the gearbox command crossing the diferentes positions (P R N D), the gearbox shake the car.
The gearbox light is on at the dashboard and the P0753 (solenoid A) is showed by the OBD readings.

I am absolutely lost with that issue... what is the next I have to check?

Thanks in advanced

 

If with your hand twist the top of the butterfly to the idle stop do you have a butterfly that is binding and not allowed to by spring force return to the idle stop ?

This is common and addressed by a Jaguar TSB and cleaning of the butterfly area and a better air / oil separator in the crankcase breathing system or you can periodically keep it clean

The transmission connector can get dirty affecting a return transmission speed sensor signal to the transmission ECU which in turn communicates with the engine ECU as they coordinate their activities together

The transmission connector fault from reading usually happens as you are shifting the select lever

This could explain your transmission light and shift solenoid fault

The connector is easy to get to on the left side rear without jacking the car and there is a trick to getting it off and it does not simply twist off


It is the black connector, another pic coming




Pic coming

 

Yes, I tried to close the throttle butterfly by hand but it was not possible... it was closed. The TPS is correct because the opening mesure by the OBD shows that it is okay. Also the butterfly is clean, or it was, because now has engine oil that comes from the breather hose.

The thing is that yesterday the revs was stabilized at 800. Then when put the revs up with the pedal or by hand (moving the butterfly) the revs didn't go down. That is what make me think that the problem is caused by the gearbox solenoid or maybe the cable malfunction...
Correct me if I wrong but for the XJR x300 the gearbox is the GM 4L80-E.

This evening I will check the gearbox connectors and exact model and brand from my gearbox.

Thanks Parker 7
regards

 

Yes the supercharged inline 6 and the V12 use the GM transmission

Which engine do you have to make sure we are talking about the correct one

 

It is a XJR inline 6 MY1994.

 

To remove the connector on the ZF4HP24 transmission you must first move straight back on the connector to unlock and only then rotate it off

There is a good picture showing the trick to rotating off because the items too close around it do not allow your fingers or tools to grip the connector shell

The use of tie wraps gripping the shell helps

 

Ok supercharged with the blower on top