symptoms of a duff throttle pot
symptoms of a duff throttle pot
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Discussion

Meatball

Original Poster:

1,638 posts

241 months

Sunday 1st May 2011
quotequote all
How would i know its playing up? Lots of part throttle shunting? poor throttle response?

Edited by Meatball on Sunday 1st May 16:04

Simon says

19,462 posts

252 months

Sunday 1st May 2011
quotequote all
Meatball said:
How would i know its playing up? Lots of part throttle shunting? poor throttle response?

Edited by Meatball on Sunday 1st May 16:04
Hi Ben,why dont you open up TunerStudio and open up Tools/Calibrate TPS then look at the second box out and slowly squeeze the throttle to see you are getting a nice linear value sweep with no drop outs or glitches perform this both hot and cold as the TPS rheostat can fail during temp fluctuations,how do i know this?....... because I had this very part fail when I was running the CUX system years ago rolleyes it was a complete bh to track down as by the time you popped the bonnet and checked the values it would behave itself(perfect linear value)it only showed on my 3rd attempt off the car and even then I at to wait for the problem to get worse(more track wear)in saying all this it did not cause any shunting just random dropping out of power under constant throttle i.e A roads and Motorways eek it may do it during an 1/2 journey sometimes not for a couple of days shoot still woth checking though in case yours as worn lower down the scale,fortunately I purchased a genuine 1 from my local LR agent for about £65 trade they have since gone up considerably,although I think one of the TVR specialist's as them reasonably priced at the moment thumbup

Meatball

Original Poster:

1,638 posts

241 months

Sunday 1st May 2011
quotequote all
Hi Simon,
I did try the tuner studio route and it does appear to be a smooth sweep, but the pot im using had to be repaired due to the wire snapping as it enters the body....guess the repairs not repaired whistlehehe
The shunt as i called it feels like the engines cutting the fuel, then as i pump the gas to recover it springs back to life.
the fun and games carry on.

BTW ive got a nice 1000rpm idle now smile

minkybob

341 posts

202 months

Sunday 1st May 2011
quotequote all
Hi,

I had a faulty trottle pot, symtems were car cutting to idle with gas pedel down then suddenly cutting back in.
It was found by diagnostic guys fitting there onboard thing! and going for a drive, it would somtimes go miles with no problem then start. Pain in the arse.
Hope this helps.
Cheers

Simon says

19,462 posts

252 months

Sunday 1st May 2011
quotequote all
minkybob said:
Hi,

I had a faulty trottle pot, symtems were car cutting to idle with gas pedel down then suddenly cutting back in.
It was found by diagnostic guys fitting there onboard thing! and going for a drive, it would somtimes go miles with no problem then start. Pain in the arse.
Hope this helps.
Cheers
Yep,thats the one yes Ben have you tried running a Datalog session scratchchin could try running Diagnostics too as it's all there with TunerStudio may take a while to analyse the data I find but always worthwhile better than watching CreaseEnders or Corrie anyway rolleyes


Edited by Simon says on Sunday 1st May 19:28

Meatball

Original Poster:

1,638 posts

241 months

Sunday 1st May 2011
quotequote all
Been tinkering in the man cave, the throttle pot wiring is starting to get very brittle....my earlier repair was fine but it had frayed/snapped further down now by the connector under the plenum. Ill give her another run tommorow and see if shes ok.
Thanks for the help chaps

Simon says

19,462 posts

252 months

Sunday 1st May 2011
quotequote all
Meatball said:
Been tinkering in the man cave, the throttle pot wiring is starting to get very brittle....my earlier repair was fine but it had frayed/snapped further down now by the connector under the plenum. Ill give her another run tommorow and see if shes ok.
Thanks for the help chaps
No problem Ben,think your in the right area anyway wink

adyw

388 posts

274 months

Sunday 1st May 2011
quotequote all
Ben,
hook the pot up to a metre, but put the reading onto resistance then twist the pot and see if the resistance goes up smoothly,
I had a faulty one, which gave me a flat spot of resistance on 70% throttle, eg resistance did not change for about 5% then started again.

Meatball

Original Poster:

1,638 posts

241 months

Monday 2nd May 2011
quotequote all
was looking (closer paperbag)on the tuner studios again and it looks like the pots jumping and loosing resistance if i add pressure very slowly, it seems to jump forward 10% around the first 1/3 of the rev range. Its also dropping back a touch to, so im going to try a new pot...where the cheapest place to get one?

Pupp

13,016 posts

303 months

Monday 2nd May 2011
quotequote all
Emerald used to do some generic ones at a reasonable price but I'm not sure how easily they would mate with the Rover throttle spindle and fastener holes. Post up what you do source as I need one! wink

Meatball

Original Poster:

1,638 posts

241 months

Monday 2nd May 2011
quotequote all
Pupp said:
Emerald used to do some generic ones at a reasonable price but I'm not sure how easily they would mate with the Rover throttle spindle and fastener holes. Post up what you do source as I need one! wink
Flea bay cheaper than most. wink
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&am...

scotty_d

6,795 posts

225 months

Monday 2nd May 2011
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When mine packed in it would not idle very well and then cut out if left t idle for a few minutes

EggsBenedict

1,796 posts

205 months

Tuesday 3rd May 2011
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There's a thread on the S forum with Barkychoc messing about with one and an oscilloscope. I saw it just as I was going offline, so I don't know if it helps at all.

Simon says

19,462 posts

252 months

Tuesday 3rd May 2011
quotequote all
To be honest you don't need to get as involved as using a scope to diagnosis for what is nothing more than a rheostat,it's simulating the temp/throttle position where the fault occurs that's the hard bit frown Ben if your not getting a nice linear action in your TS logs then you have found your fault be it poor wire connection worn TPS inner tracks etc wink