Hi, I have an odd problem with my car, it is a x type 2.5 v6 2004 estate manual. It has a very low idle, around 500rpm and has stalled a couple of times coming to a stop in neutral. If I pull a wire from the throttle body the idle becomes around 1500 rpm. This wire connects to the connector circled in the image attached.
Would I be correct saying that this is an idle control valve? If not what is it?
Is is possible to mend this or would it be better to buy a new throttle body?
Tia, John

 

This is according to a cheap ebay obd reader. Car has also recently been serviced and spark plugs replaced, this did not affect the problem.

 

Throttle position sensor.
Heed post #3, if it ends up needing a new throttle body (WAY $$$ from Jag), contact member Dr Dome who parts out X's.

https://www.jaguarforums.com/forum/x...-sensor-86984/

 

Thank you for correcting me, I went to take it off today and it's an annoying 5 sided torx bit that I don't have. I've ordered some so when they arrive ill take the tps off and give it a clean. If that doesn't solve my problem I'll look at a new throttle body.

 

Hi John,

Sorry for being a bit late to this party, but perhaps this might help.
Being a 2.5 or 3.0 V6 engine, your throttle body does not have an idle speed control valve, that I believe is only present on the 2.1 V6 (like mine) which has a manual throttle cable activating the throttle position, so an idle speed valve is required to manually alter my manual model of throttle body during engine start, whereas the 2.5 and 3.0 engines are fully electronic control.
The 2.5 and 3.0 V6 has a fly-by-wire control, your accelerator pedal is activating a dual variable resistor sender module in the cabin which is connected to the ECU allowing it to interpret the physical pedal position. The ECU then drives the throttle motor back or forth until it gets sufficient feedback from the throttle position sensor (TPS) to validate that the throttle has physically reached the desired user pedal position.

Dell is most likely right...adjusting the throttle rest position (torx screw) slightly may certainly fix your problem, as over time there can be some additional play in spindle bushings or reduced clearances due to wear of the screw end or end stop which may decrease the original clearance setting. I would also certainly take a close look at gently removing any road grime deposits that you tend to find accumulating around the edge of the throttle butterfly and on the throttle body venturi as they will trick restrict airflow at idle and needlessly increase vacuum.
There are some very good and inexpensive throttle body cleaners which you can use to de-coke the inner airway, and if you use a cotton bud you can delicately encourage more stubborn deposits of the lip of the butterfly.

There are two connectors to the throttle body in your photo but only one 6-way connector listed for the throttle body of the 2.5 and 3.0 engines that I can see in the electrical schematic (Connector EN-95), but I suspect that harness in practice might be split into two final connectors to service the TPS (4 wires) and the throttle motor (2 wires). Unfortunately I can't easily verify as my throttle body is different. Depending on which you are unplugging (it looks like you might be unplugging the motor as with the shape of the black cover there looks to be a flat motor and gear housing at that end of the throttle body), the engine vacuum my be sufficient to force the ungoverned butterfly open a bit, giving you the resultant higher revs you observed.

 

Not too late at all, I had to order some 5 pointed torx bits as I didn't have any and they have only just arrived. I will adjust what you have suggested and give it a clean and hopefully that will clear the problem.
thanks

 

Would you say it is safe to spray cleaner on the throttle body whilst the engine is running?
Sorry if that's dumb question, This is my second car and my last car was a mini

 

https://www.jaguarforums.com/forum/x...dy-worth-8890/

 

Hi John,

I took my throttle body off to have enough access to give it a good thorough clean, as the deposits were pretty heavy and it needed some very gentle agitation.
Judging by the condition of mine, I doubt the previous owner or the garages he was taking it to ever cleaned the throttle body or the air mass sensor.
I used a CRC throttle body cleaner aerosol product on the throttle body and their Air Mass sensor aerosol product for "de-gunging" the air mass sensor too at the same time.

You may still need to gently open the butterfly up a bit to get to the crucial pinch point where the butterfly rests at idle, to successfully clean that restriction area of the body and also butterfly edges.
I personally would not be in a hurry to spray any of these products into a running engine, as they are solvent based and I am not sure how combustible they are - who needs a nasty blow back experience!
One a practical note I would prefer that the gunk that gets dislodged ran onto my bench, rather than into the intake manifold and through the engine.
Probably only an extra 15 minutes to remove and refit the throttle body; a small price to pay for getting better access to both sides of the body and to have better control of the task.