Just a heads up to the community if anyone is needing a new TPS sensor for their 2.1 V6 cat.
After having some issues with mine, and seeing the only original part is a complete throttle body, I began searching around and found that a Walker Products sensor (part# 200-1060) seems to fit nicely.
Physically it is the same package, termination type and internal drive spline shape, and orientation.
The only difference I found was the internal resistor measurement of the original TPS was about 3.4K ohms and the Walker replacement seems to be about 4.5K ohms.
That variation doesn't seem to matter much to the ECM as it appears to compensate after a short period of time to re-adjust idle speed back to the normal 750rpm.

The symptoms I had was a annoying flat spot just at the beginning of acceleration just from rest.
I also was noticing that flat spot between gear changes (auto) under light acceleration also.
I could not find any vacuum leaks anywhere - which was the logical place I started.
I had managed to mask the issue by slightly adjusting the throttle body butterfly end stop by about 1 turn, prior to obtaining a new TPS sensor.

I suspect the TPS was just worn out in the off idle position and the ECM was not initially increasing fuel until it received a more logical reading, therefore the air availability was increasing in advance of fuel.
This TPS is a single resistor unit as the 2.1 engine throttle body is cable pulled, not the same as the TPS used in the 2.5 and 3.0 models that have dual sweep resistors for 'fly by wire' operation.

I know most of you will have either the 2.5 or 3.0 V6 engines, but I suspect there are quite a few members of this forum that are in regions where they may have a 2.1 powered model.
My car has done 124,500 Km and spent its first 13 years crawling around the traffic in Japan, so I expect a lot of idling and slow congested traffic movement was the initial diet of my cat.

Hope this helps someone else that might be having some niggles with their car and saves them spending time looking for phantom vacuum leaks for the same symptoms.

 

Mark, that's a great heads-up and detailed explanation. Well worked through and big 'thank you' for sharing, as the OEM TPS sensor is listed here as NLA, and new TB replacements are priced higher than a good productive ewe - of which last week's record here for an entire pen of 20, was AU$980 each!

Mind you, they probably didn't have flat spots
Cheers,
Ken

 

Thanks for the feedback. Yes the car is so much smoother now. It was certainly bugging the crap out of me.
Going to be interesting to see if I notice a little bit more range out of a tank of fuel (mainly round town driving at the moment).

Next job....Front shocks and jounce bump stops to get rid of some of the clattering over manhole hatches and potholes.
Hmmm flat spots on a ewe.........Not unless the tupping Ram had given them too much of a hard time!
Good god, that is one heck of a per unit cost for a ewe there currently.
Is that because of the de-stocking that has occurred there due to successive droughts?
Their teeth will be getting prematurely ground down with grazing the stubble there as well I suspect.

 

Just a point of clarity, the ewes were all pregnant.

 

Yes, all pregnant, but wow, what a price! Yes again, widespread drought followed by bushfires has seen massive stock losses, so there is a frenzy of restocking underway. Previous week, story was of a dry old dairy cow fetching over $1500 from a butcher glad to get it!

Vision of Mark clattering over 'manhole covers' has me twitchy, but I bet your X-Type settles into a more frugal state. I am constantly surprised how a good clean of the entire induction side can achieve significant benefit. Pls let us know some before/after results when you can settle her down into some long-legged runs.

Cheers mate,

 

THANKS MARK.

I have one on the way for my 2010 Beast.

Could be fun, as the front screw is missing the "philips teeth", meaning someone has been here before me, bugga.

I will update my findings when it done and dusted.

The Ewes, I will leave alone, HA.

 

Hi Grant,
I'll be interested to know how you get on with your replacement too.
The internal resistor was not open circuit, just slightly erratic in low end sweep.
Not easy to measure tracking accuracy with a digital meter as the 'noise' of the wiper continuity would probably show up far better with an old moving coil meter showing the meter twitching.
.
Just a reminder that the initial idle you will get with the new TPS installed may be artificially high.
I was seeing around 1100rpm in park/neutral and 900 in drive.
The ECM does take a bit of time to 'realize' that the baseline has changed.
Probably took about two or three short 10 minute trips for it to start and settle down into lower idle state, did seem to hunt a bit and then drop down, but great now (two weeks since change).
The engine seems a lot more willing to respond now too.

I read on one of Thermo's recent replies to the behaviour of the ECM clearing 'Check Engine" error lights, the ECM needs to see 10,000 engine turns to class the start cycle as a valid event.
Just wondering if the learning cycle for ECM to reassess and compensate for a new TPS is somewhat similar.

As I said, hope this helps someone else recycle their throttle body.

 

Thanks again Mark,

I was thinking of pulling the Fuse 19 = ECM, and #32 = TCM, while I played with this sucker.

That should drain any residual I think????

I will take the throttle off due to that rounded out screw, safer and easier on my old back than leaning over the beast.

Talk soon.

 

Mark,

TPS Arrived.

Fitted today, fuse 19 and 32 pulled for the duration.

Old one was the WORST flaky TPS I have even come across.

At rest, 013, then 009, back to 030, 015, etc etc, and this was all in about 5mm of rotation.

Went full scale with the thing, then it rested at 024, 008, 013, 015, 024, 009, again in about 5mm of rotation.

I thought some of the V12 ones were sad, this one takes the cake for sure.

New one at rest is 003, and a steady increment rise, as I would expect.

Started the beast, idled at 1500, then did the 1000 to 1500 hunting about 6 times, then settled at 1000. I raised the revs to 2500, and let it idle, repeated a few times, and its settled at 900 after 15 minutes of running, ran it through the gears a few times also.

I will not use the car for a few days, Management has decreed we will use the S Type for a while, and who am I to argue with Management.

Let you know when I know more.

 

Hi Grant,
Good to hear your new TPS arrived and you managed to fit it OK despite the rounded screw hassle.
I didn't pull the fuses on mine, so the ECM did seem to take a bit more time to acclimatize to the new part's insertion.
I would definitely suggest pulling those fuses so the ECM is forced back to using the base mapping tables, to then quickly relearn the local parameters of the engine and environment.

I think we need to treat the TPS as a consumable item, prone to mechanical wear of the resistor and contacts.
They can create some weird behaviour when they are unstable in their operation.
Fly by wire cars need to consider the accelerator sender resistor assembly as well will suffer similar deterioration, as it is doing the exact same movements as their TPS is following.

Note to those that might follow:
I actually received a faulty TPS that had an occasional 'binding issue' creating a weakened return of the new TPS to home position.
It took two goes for me to fix the faulty part by relieving some of the compression tension of the TPS backing plate incorrectly located during manufacture. Trust me to get the one faulty part in their stock!.

I only mention this as I just want to share that you should manually operate the new TPS several times with a broad screwdriver to ensure a strong and smooth return operation of your new part before fitting.
My dud part caught me out by creating very occasional gearbox errors where it would occasionally not up-change and then lock out into limp mode unit I had disconnected battery for 10 minutes.
Sometimes it would eventually start gear changing up and down but it was very very harsh after initial faulting began, and until you cleared the ECM it would not run smoothly again.
The first time it froze the gear changes, I pulled over out of traffic then I shut off car. I was then a total non starter - crank but no start with CEL light lit.
The TPS not returning properly created an imbalance in feedback signals to the ECM that was reading manifold vacuum via the MAP sensor, versus engine revs and realizing the throttle butterfly could not be where the TPS was saying it was.
It totally confused the ECM that then confused the gearbox as to what gear to be in and whether I was trying to accelerate, or was in overrun down a hill. Eventually it would throw its hands up and says enough is enough - gearbox warning and limp home or CEL

Hasn't missed a beat since sorting that binding issue out......smooth shifting and feather control of the throttle.....YAY!

 

Good info there also Mark.

Out of habit (way too many V12 TPS issues over the years), I worked that sucker many times, and observed the SMOOTH rise in Ohms each time.

Rounded screws, NO ISSUES, 1/2" drive rattle gun, Zoom, Zoom, out they came, and never went back, found some better Hex head 5mm replacements.

Test drive to come, maybe next week when the storms pass and Management gives the all clear to put the S back in storage, HA.

 

FORGOT, it happens.

That fuse 19 and 32 is related to the Update X Type, AKA 2008 to end of production, mine bing Dec2009 Build.

Easily identified by the Mesh style grille, and different snout.

Earlier cars, from what I have read on here, it is Fuse 32 only.

Read your cars owners handbook to confirm what fuses do what, simple.

 

UPDATE:

The S Type is back in storage.

Drove this X Type for the 1st time since installing that TPS.

Idle seemed a tad high, 1000rpm in Park, but SMOOTH as it should be.

Gearchange is now smooth and near unnoticed, either up or down.

Performance, suburbs with 50KPH limits, is better than ever.

The dreaded hiccup, when taking off quickly to insert in a traffic gap, is GONE.

I know it takes about 350Kms to reset the brains, and that will happen in due course, but teh driveability of the whole package is now superb.

Time we returned home, approx 30Kms, lots of stop start happenings, the idle is back to normal, and that is a good sign.

I noted a comment by Thermo in a thread by Dell, about the Injector earth point on the RH shocker tower. Found it, 8mm headed bolt, and removed, OOPS, the amount of gunge in there was worse than I thought an 11 year old car should be. Cleaned up, star washer on that bolt, and refitted. Just the fact of real lousy contact has me now looking at all the earths I can find.

 

Hi Grant,

That is great news.
I have for the first time got over 400km out of a tank (450+) with just round town and back and forth driving to work. Refilled late last week and monitoring this tank as well.
I don't always drive sedately and have a tendency to engage the sport mode quite frequently to give the trans some more life when I am able to give the Cat some much needed exercise.
Needless to say it is a completely different car to drive after doing the TPS, especially since I did the trans fluid prior to TPS.
Still have the front shocks etc. to get organised.

Have noted your comment about earthing points from Thermo........I will be checking mine as the engine can still produce an occasional cough at around 1350 to 1400RPM when in 4th at around 55kph under light acceleration going up an incline.
Have already done spark plugs and checked coils and done the "Start ya Bast@rd" starter fluid test for finding any vacuum leaks - none found.
Earthing points are my next check.
I might also pull out and test the ignition suppressor capacitor mounted up front.- I don't have any noise in the sound system but worth a check while I am there as it is on the coil supply line so could create some oddities.


2005 X-Type Saloon Grounding Points

 

Mark,

Thanks for that earth point chart, makes it easier.

Gave mine some beans yesterday, OOPS, it really wants to boogie now, so that TPS was reeking havoc me thinks.

Catch can next, to keep that oily crap out of the manifold. That MAF has oily mist on it again.

Car needs a good hard LONG 8 hour run, but the borders are closed, so it will have to wait.

 

H2O2steam, I ordered a Walker TPS a few months ago and have had it sitting in the glove compartment of my car. I finally installed it today. Wow! I seem to have a new car. The small flat spots and stuttering I had at low speeds when accelerating have gone and all is well. My idle speed is slightly higher, but I read how yours did that for awhile and will wait to see if it does the same. Took me maybe 10 minutes, as I had changed the screws last time I had them out and also put some copper ease grease own the threads and under the head of them. Thanks for your earlier advice and I also would recommend the Walker 200-1060 TPS to anyone seeking one. The price is a little higher than others, but this one works.

 

Really glad the new TPS is working out for you and thanks for posting your response.

Mine is still going fine, although I haven't been driving it much recently (The XJ8 has been getting the miles on it at present).