Throttle position sensor, success story.

[GrayUK]

Well...once again this web site has helped me solve a problem with my Omega.
Last week it was the power sounder (thanks Debs).

The other problem started about 6 months ago when I brought the car.
I kept getting a random ECU light (one with the spanner). I took it back under warranty and the garage did their tech bit on it. Lambda sensors they said, we will replace the problem part. This they did and then on the way home up popped the light again. It was random in the way it popped up, sometimes not for days. It had no effect on the running of the engine that I could detect, if you stopped and turned off the ignition it would clear and then not come back on. So I took it back and they checked the code....Lambda sensor again. So, they said that this time they would put a genuine VX part in, that should do it...... well, on the way home it popped up again, I rang them and they said to take it to Vauxhalls and they would pay the bill.
This I did and Vauxhalls said the code actually said it was the throttle position being in an unexpected position for the engine as it was running at the time. They followed the book, which involved clearing the 'learned' values and assured me it would be OK now. The bill was £90.0 (paid by the garage I brought it from).

Well...you have guessed it, it came on again! VX said that it was a faulty ECU which would cost around £800 to fit. I did not believe it was this and asked what happened if they changed it and the fault was still there? The answer was effectively that was the risk I had to take! Not happy with this and very happy with everything else on the car I decided to leave it and carry on with the light popping up every so often.
Over the last month the light got more regular and would come on within a minute of setting off.

When reading this forum I found this thread
http://www.omegaowners.com/forum/YaBB.pl?num=1202157944
Which awakened my interest the problem again.
The thread pointed me to
//www.omegaowners.com/forum/YaBB.pl?num=1162397695
This awakened my interest the problem again.
Well today i went out an brought the 2 gaskets and followed the procedure laid out.
I can confirm that the hoses were partly blocked with sludge and the small hole mentioned was blocked.
After much cleaning (it was in a state) i reassembled and started the engine. I know I had had an effect because the engine ran rough for a minute as it re-learned the changed situation.
I took it out for a 10-mile drive and all is well, no light, no problem. The engine runs really well, and I am sure it now changes gear better on the auto box.

So, lesson learned, 2 garages failed to solve this problem, the OOF had the answer!
I would recommend this procedure on the carb to anyone who my have random ECU light, to be honest, it is so easy to do and the car must run better when all that crap is cleared out, I think it is worth just doing it!

Well done OOF slap yourself on the back.

[TheBoy]

Great news

[mars]

Hiya, bought my 2.2 cdx a month ago from a trader. Within a few miles of picking it up same light appeared on my dash. Phoned trader who booked it in at a garage he uses and i took the car there. They plugged in diagnostic and a long list of possible faults appeared. They cleared memory and told me next time light comes on to take it back asap. Drove away and got half mile up road and light came on, turned round and went back. They plugged it in again and only one fault appeared, throttle position sensor.  They fixed it at traders expense as it is under warranty and several hundred miles later it has not come on again.

[Debs.]

Brill` news Paul!  

Well done; for both the research and the execution of the repair.....
Having that EML coming-on 'whenever' it wanted-to, really must`ve put a downer on trips out.

Wouldn`t you think that Vx. would have been able to fathom such a well documented (and doubtlessly-common) issue though?  

Really glad your prob.`s sorted.  

[GrayUK]

Thanks Debs...by the way....it is still quiet around here!

[Andy B]

........and asked what happened if they changed it and the fault was still there? The answer was effectively that was the risk I had to take!  .......

This seems to be the standard responce from dealers of any kind. It really amazes me that you go and ask the 'experts' to diagnose & repair a particular fault. The dealer guesses the wrong fault & repair & then still expects the paying customer to foot the bill for their mistake.    
Well done for sorting it out.  [smiley=thumbup.gif]

[GrayUK]

Andy B
Yes, bad really, in most other areas of life that does not happen.

Thanks for the Thanks.

[mars]

It is sad and also frightening to think how many people trust the dealers and get stung for vast amounts of money for things which could have cost almost nothing.

[GrayUK]

Brill` news Paul!  


Wouldn`t you think that Vx. would have been able to fathom such a well documented (and doubtlessly-common) issue though?  

Debs
I think the problem today is that a lot of these guys are not what i would call 'mechanics' they dont think through a problem. If the computer says it is the sensor then it MUST be the sensor  
If that does not fix it then the book says it must be the ECU...and so on.  :-/

Paul

[GrayUK]

Mars
This one of the reasons why i felt it was worth posting the story.
My car is in great condition, low milage for year (2001 65,000) with full sevice history. But i was amazed at the state of the pipes and carb inlet.
I think it is something that would be worth doing anyway just as a job worth doing!
The 2 gaskets cost £1.98 and it took about 1 hour to do  
Got to be worth it. :-?

[Martin_1962]

I did it yearly on my old 2.0CD

[GrayUK]

Just a quick update.
Took the car out today for a run to Oxford, for me that is about 1 hr each way.

The drive is a mix of dual carriageways, stop start traffic and normal roads, in fact a good test of the system.
The light did not come on at all so I consider it definitely cured.  [smiley=beer.gif]
But as I mentioned yesterday the whole thing seams better, auto-changes are smoother, and more precise.

But the real good news is the petrol consumption.

Average speed was 36mph for the trip and she turned in 29.6mpg!
I do this trip regularly and the best I have ever got was 27 mpg and just recently it was down at 24mpg.

So..total success in all areas..

Thanks again OOF  [smiley=2vrolijk_08.gif]

[mark.adams]

I know I had had an effect because the engine ran rough for a minute as it re-learned the changed situation.

This part caught my attention, i never realised it would have to re-learn parameters again, the rough running after cleaning it out made me think i had done something wrong....

[Marks DTM Calib]

Yes, the state of teh modern day fitter is a conecern, cars are getting more complex and teh fitters are not keeping up.

Note I use the term fitters, there are few who work on cars for a living these days who could do a full engine re-build adn hence in my book they are not mechanics.

But, good news on the fix.

[GrayUK]

Yes, my understanding is that it does that.
When the lambda sensor was changed previously VX wiped the memory of learned parameters, it runs rough for a short while and then settles down. You are supposed to take it out for a 'normal' run (I am told) to help it relearn the norms.