hesitation/jerky travel solved at last!
Discussion
Following a couple of months of jerky travel (won't let you drive smoothly on v light throttle), i've sorted it.
A nameless main dealer had no joy, both throttle pots replaced (twice) new ht leads, plugs etc, & once you had reset the adaptive maps the car would run fine (until the car was run for a couple of miles & the adaptives would change).
Turns out to be the throttle link rod ball joints - have just replaced & the kangaroo effect is gone.
If you are having this problem, grab the link rod in the centre (where it is knurled) & gently rock from side to side. If you have ANY play there, it will contribute to the problem
What happens is, as you accelerate, the n/s bank opens first, the slack is then taken up & the o/s bank opens a fraction later, & the reverse when you close the throttle. Though the play in the linkage may seem tiny, the throttle pots are so sensitive to small movements the ecu gets confused = shitty low speed driving.
Hope this helps anyone who is having problems, i can post the TVR part numbers if required, i think the lot was just over twenty quid.
Thanks also to Joospeed for his patience & time when i threw a thousand "could this be the problem?" type questions at him.
Darren.
A nameless main dealer had no joy, both throttle pots replaced (twice) new ht leads, plugs etc, & once you had reset the adaptive maps the car would run fine (until the car was run for a couple of miles & the adaptives would change).
Turns out to be the throttle link rod ball joints - have just replaced & the kangaroo effect is gone.
If you are having this problem, grab the link rod in the centre (where it is knurled) & gently rock from side to side. If you have ANY play there, it will contribute to the problem
What happens is, as you accelerate, the n/s bank opens first, the slack is then taken up & the o/s bank opens a fraction later, & the reverse when you close the throttle. Though the play in the linkage may seem tiny, the throttle pots are so sensitive to small movements the ecu gets confused = shitty low speed driving.
Hope this helps anyone who is having problems, i can post the TVR part numbers if required, i think the lot was just over twenty quid.
Thanks also to Joospeed for his patience & time when i threw a thousand "could this be the problem?" type questions at him.
Darren.
I found the same problem with my linkage when I was replacing the bits after a starter motor overhaul last night (again some good tips from Joolz). Although you couldnt tell by just turning the throttle, it was certainly visible when you looked at the butterflies that one bank was opening before the other. I have adjusted the linkage so it's tight and both banks open together, but could really do with a new one if they are only a score. Numbers will be appreciated.
Okay, here are the part no's:
E2596 Throttle ball joint (RH) £4.37
E2676 Throttle ball joint (LH) £4.91
E2706 Throttle link adj (RHT) £1.44
E2698 Throttle link adj rod £5.77 all + vat
Add £20 if you want the actual rod itself (the above parts are just the end balljoints/ threads). you get the locknuts & retaining pins in the above as well.
Note the above fits a 97 4.2, not sure about 4.5 etc
I ordered direct from TVR parts (speak to Mick) as i did not think the dealers would keep the parts in stock.
Darren.
E2596 Throttle ball joint (RH) £4.37
E2676 Throttle ball joint (LH) £4.91
E2706 Throttle link adj (RHT) £1.44
E2698 Throttle link adj rod £5.77 all + vat
Add £20 if you want the actual rod itself (the above parts are just the end balljoints/ threads). you get the locknuts & retaining pins in the above as well.
Note the above fits a 97 4.2, not sure about 4.5 etc
I ordered direct from TVR parts (speak to Mick) as i did not think the dealers would keep the parts in stock.
Darren.
Julian64 said:
I looked at this a ouple of weeks ago. Strangely the idea of it being an expansile metal hit me too.
I thought I might brush the dust off the lathe and make a polycarbonate one?
You're looking at it from the wrong angle .. have another think about what's happening to the engine ..
joospeed said:
Julian64 said:
I looked at this a ouple of weeks ago. Strangely the idea of it being an expansile metal hit me too.
I thought I might brush the dust off the lathe and make a polycarbonate one?
You're looking at it from the wrong angle .. have another think about what's happening to the engine ..
Gotta take it apart again for that, you tease !!!!
You've already got me doing my homework on that ECU. I have just spent £100 at farnells on the bits required to be able to map the engine on the fly.
Or at least I think its gonna do that :fingerscrossed: you didn't really want that ECU back did you
. >> Edited by Julian64 on Tuesday 9th December 14:40
Julian64 said:
Julian64 said:
I looked at this a ouple of weeks ago. Strangely the idea of it being an expansile metal hit me too.
I thought I might brush the dust off the lathe and make a polycarbonate one?
You're looking at it from the wrong angle .. have another think about what's happening to the engine ..
Gotta take it apart again for that, you tease !!!!
You've already got me doing my homework on that ECU. I have just spent £100 at farnells on the bits required to be able to map the engine on the fly.
Or at least I think its gonna do that :fingerscrossed: you didn't really want that ECU back did you
>> Edited by Julian64 on Tuesday 9th December 14:40
DON'T KILL MY ECU!!!!!!joospeed said:
joospeed said:
Julian64 said:
I looked at this a ouple of weeks ago. Strangely the idea of it being an expansile metal hit me too.
I thought I might brush the dust off the lathe and make a polycarbonate one?
You're looking at it from the wrong angle .. have another think about what's happening to the engine ..
Gotta take it apart again for that, you tease !!!!
You've already got me doing my homework on that ECU. I have just spent £100 at farnells on the bits required to be able to map the engine on the fly.
Or at least I think its gonna do that :fingerscrossed: you didn't really want that ECU back did you
>> Edited by Julian64 on Tuesday 9th December 14:40
How much do ECU's cost ?
Nope, on the other hand you better not answer that. I may end up with performance anxiety problems. I will be real careful. A little while to go yet anyway.
Top tip Darren!
Finally got round to changing mine at the weekend. There was quite a bit of free play in each balljoint.
Now both have been changed slow progress in traffic is far better with the jerkiness eradicated.
Just had mine serviced and the ironic thing is I was told the only way to cure the jerkiness was to have the throttle body spindles rebushed at a cost of £500!!! - Pahhh
Finally got round to changing mine at the weekend. There was quite a bit of free play in each balljoint.
Now both have been changed slow progress in traffic is far better with the jerkiness eradicated.
Just had mine serviced and the ironic thing is I was told the only way to cure the jerkiness was to have the throttle body spindles rebushed at a cost of £500!!! - Pahhh
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