Hi guys,

I have a 1999 4.6 Thor V8 on which I replaced the original BOSCH TPS with a £25 variant from JGS 4x4 when hunting down a problems I had which is now finally fixed, it wasn’t the TPS at fault. However, now the car seems to judder and almost loose power momentarily while accelerating. When the TPS is disconnected it doesn’t do this. I noticed on live data when idling the Throttle angle will erratically jump about and do strange things. It will read 0% and then spoke to 72% and then drop to 27% so on and so on. Is this down to the aftermarket cheap TPS I replaced the original with. Annoyingly I didn’t keep the old one so I can hook that one back on and see if it still does it. I have reset adaptions and it still does it with the TPS plugged in.

It also revs up high on start up and sits at around 2,500 revs until I rev it and it drops back down. Could that also be linked with this or is that more likely to be a sticking IAC valve??
 
Very likely a faulty TPS.
Try a 'wiggle test' of all of its the wiring you can get at & see if anything happens.
Plenty on ebay etc for various prices. Can't say I'm a fan of cheap aftermarket stuff though.
You could raise the issue with the suppliers of your TPS but many won't accept returns of electrical items that have been fitted.
 
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I thought it may be. Any idea where I could get a new genuine one from. Been looking and see them sat at around £250-£400. Is that about right?

Rimmer Bros for genuine.

If you want cheap then eBay scrapper one. Classic Rides North Wales or someone might remember what Charles's pseudonym is. Cn4x4?
 
Rimmer Bros for genuine.

If you want cheap then eBay scrapper one. Classic Rides North Wales or someone might remember what Charles's pseudonym is. Cn4x4?
Not sure if the the same chap you are on about but I did order the outer handle for mine from a chap on eBay called cn4x4sss so I assume that’s that’s the one you are on about.
 
Not sure if the the same chap you are on about but I did order the outer handle for mine from a chap on eBay called cn4x4sss so I assume that’s that’s the one you are on about.
That's charles he's the bloke who supplied/fitted the engine for me
 
I would check it with a multi-meter before assuming it's the cause of erratic readings. Definitely clean the IACV & throttle body inside as well.
 
I would check it with a multi-meter before assuming it's the cause of erratic readings. Definitely clean the IACV & throttle body inside as well.
If you do then as already said by datatek the swing of the readings must be smooooth without any sticking or sudden jumps.
 

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