This is a step by step guide to removing the TPS on the x14xe/x16xe engine. On any other engine this would be a very simple task but not on these engines.

Introduction

The TPS informs the ECU of how much throttle is being applied at any given time, allowing it to adjust fuel mixture more quickly. It also tells the ECU when to go into idle control mode.

A lot of idling problems can be linked down to the TPS not reading 0% throttle causing the revs to go up and down erratically . The revs go up and down due to the ECU creating a rich/lean mixture due to lambda readings and injector pulse width. (when in idle mode the ECU doesn't do this) Other issues can be stalling and surging.
In more serious cases flat spots can be evident as well as needing to pump the throttle to start the engine.

Tools
Rachet
rachet sockets 7mm, 8mm, 10mm, 13mm. best to have a full set.
torx keys t10, t15, t20, t25, t30 others may also be needed.
various spanners (10mm in particular)
throttle body gasket
inlet manifold top gasket
loads of rags
coolant (if you plan on replacing it)
bucket or other such coolant capturing vessle.
loads of rags
various pliers and clamps
wd40
a couple of plasters.

Step 1

The TPS is right down where the red arrow points


If you don't to get wet later then you can drain some coolant. I couldn't find the lower radiator hose so i disconnected the left hand hose from the coolant tank and fed it down a tube and into a bucket and fired the engine up until about 2 litres were withdrawn. (Bad Picture)


Step 2

Remove the battery. remove the negative terminal followed by the positive then with a deep socket extension, remove the 13mm bolt holding the battery clamp in place.


The battery should now be easily removed.

Step 3
Preparing inlet manifold

Remove Map sensor. there will be 2 10mm plastic bolts holding it on the bulkhead. remove these as well as the connector and hose going into the inlet manifold.


Now remove the brake servo hose from the inlet manifold. 19mm spanner i think.
.

Plus if you have not already done so, remove the plastic engine cover if you have one.

Next remove the fuel tank ventilation valve from the right hand side of the inlet manifold. Its held on with 1 weird star socket. a 7mm socket will get it off. Unplug the hose that goes down the back of the engine. With draw along with the hose that goes into the manifold.


Remove the hose that goes from the fuel pressure regulator to the inlet manifold.


Also remove the S hose that plugs into the camshaft cover (PCV valve)


Step 4
Remove top inlet manifold

Start by loosing all 7 of the 10mm bolts from around the top inlet manifold. starting on the left, making your way around all the bolts in a circle like fashion. loosen them up first before removing.


Now loosen any clamps that hold the rubber trunking to the inlet manifold. if you need pliers or clamps to do this you may need a helping hand.


Withdraw the top inlet manifold and you sould be left with this. remove the manifold gasket ( you may want to consider replacing) and the rubber trunking attached to the throttle body mount.


Step 5
Prepare throttle body

remove the coolant expansion tank. this isn't essential as you can move it out of the way when need be but it makes life alot easier. Undo the two 10mm bolts from the bulhead and the two hoses at the top. now pull it forward so you can get to the hose underneath. undo the clamp and remove.


Remove battery tray. four 13mm bolts.


Remove the engine earth from the throttle body mount (10mm) along with the engine wiring troth bolt (also 10mm). move the very very VERY annoying wiring troth out the the way.


Next remove the fuel pressure return hose from the fuel pressure regulator (1) (prepare for fuel splillage) 15mm spanner i think. Unplug the plug from the TPS (2) and unplug the plug from the idle control valve (3).


Next we need to remove the throttle cable from the throttle body. start off by pulling the grommit away from the bracket as shown


Then unhooking the end of the throttle cable from the throttle lever.


Around the back of the lower inlet manifold there is apparently two bolts that brace the intake pipe. I only found one. remove these so that the pipe can be pushed down on throttle body removal.


Step 6

Remove throttle body

Undo the 4 torx bolts that secure the throttle body to its mount and loosen the clamp that secures the inlet pipe to the back of the throttle body.


Now yank the throttle body out with plenty of bad language and it should come away. Undo the two coolant hoses and have a bottle on hand to catch any coolant. sorry i don't have a picture for this bit as i was very angry at the time.

The throttle body should now be free of the car. The Throttle position sensor (1) and idle control valve (2) are held on with torx bolts. mine were t15 and t20 but yours may be different.

Step 7

Reffiting

It would make sense to give the throttle body a good clean with wd40 or your preffered carb cleaner.

When you resinstall the TPS make sure it is connected to the bufferfly catch.

Install throttle body back into the car along with a new throttle body gasket (or one made of a couple of sheets of card like i did). connect the coolant hose back up (doesn't matter which order) before securing the throttle body into place. It will take a heck of a lot of persuading to get it back into place.

putting everything back together is the reverse of the removal procedure. just remember to top up your coolant.

Start engine and listen for any hissing from the throttle body area. hissing would indicate airleaks and forgotten hoses. also allow the ECU to reset its self.

Well done, you have saved yourself hundreds of pounds of labour over a stupid little sensor.

Cost

tps = 15 (cheapo) - 60??? (for propper one)
inlet manifold top gasket - 10?
throttle body gasket - 5??

Total estimated cost. 25 - 75