advice, have moved this from the Tam forum
Discussion
Right, I hope someone can suggust why my Tam seems to hesitate when accelerating, like it is struggling to find the power, but only sometimes, not all the time, although the past 2 days it seems to have got worse!
No warnings are showing, and all pressures, temps, oil/coolant levels are absolutely fine.
I took it to County TVR for a diagnostic a few weeks back, but said there's nothing wrong, but I know there is, even Chan commented on the hesitation yesterday when she drove it.
The only 'visible' sign of something being not quite right in the engine bay is one of the injector leads, that attaches to the injector/throttle body had black tape around it, suggesting the cap has split, could this possibly have something to do with it. As I said, sometimes it accelerates great, other times it seem very 'lumpy'
Hope someone can put my mind at rest, these wouldn't be symptoms of anything to do with the valves (gulp), could it?
Are De-throttle chips readily available?
Thank you
Chris
(have moved this to the Tuscan forum, as there are many more owners, and have had more experience with the S6 'traits', thank you
>>> Edited by chris watton on Thursday 29th July 13:07
No warnings are showing, and all pressures, temps, oil/coolant levels are absolutely fine.
I took it to County TVR for a diagnostic a few weeks back, but said there's nothing wrong, but I know there is, even Chan commented on the hesitation yesterday when she drove it.
The only 'visible' sign of something being not quite right in the engine bay is one of the injector leads, that attaches to the injector/throttle body had black tape around it, suggesting the cap has split, could this possibly have something to do with it. As I said, sometimes it accelerates great, other times it seem very 'lumpy'
Hope someone can put my mind at rest, these wouldn't be symptoms of anything to do with the valves (gulp), could it?
Are De-throttle chips readily available?
Thank you
Chris
(have moved this to the Tuscan forum, as there are many more owners, and have had more experience with the S6 'traits', thank you
>>> Edited by chris watton on Thursday 29th July 13:07
Sounds very much like the common problem with throttle bodies wearing. Does it happen more at higher revs? And almost cut out at 5-6k RPM? Do you ever get it at constant throttle (at high RPM, especially)? How many miles have you done?
If it is the throttle bodies, you're better off getting them replaced (with uprated ones like Dreadnought/SFR do), rather than getting the d-Throttle chip - all that'll do is even out readings over a greater period of time, affecting throttle response, etc.
Having said all that, you're not going to know unless you get it to a garage and have it checked out by a proper mechanic.
If it is the throttle bodies, you're better off getting them replaced (with uprated ones like Dreadnought/SFR do), rather than getting the d-Throttle chip - all that'll do is even out readings over a greater period of time, affecting throttle response, etc.
Having said all that, you're not going to know unless you get it to a garage and have it checked out by a proper mechanic.
Thanks J S G
If it were the throttle bodies, would that not show up on a disgnostic machine? But, if it is the throttle bodies, I wouldn't have to wait months for them, would I? I have the car booked in at County TVR next Monday, I hope they get to the bottom of it.
The prob is intermittent, and happens mostly on hard acceleration, the Tam's only done 13K!
If it were the throttle bodies, would that not show up on a disgnostic machine? But, if it is the throttle bodies, I wouldn't have to wait months for them, would I? I have the car booked in at County TVR next Monday, I hope they get to the bottom of it.
The prob is intermittent, and happens mostly on hard acceleration, the Tam's only done 13K!
It is not unknown for throttle bodies to wear, even at that low mileage. Now, if I understand correctly, the throttle bodies have two potentiometers that sense the position of the bodies, one for the first 3 cylinders, the other for the remaining 3. Sometimes these need re-balancing to make things run smoothly - less than an hour's job.
If the throttle bodies are worn, the pots give out wildly differing voltages to each other so the ECU finds it difficult to know what position they are in. The reaction to this can be 'desensitised' using the dethrottle chip. Most people report that engines run more smoothly after this little upgrade, and I can't say I have felt any difference in terms of performance. However, the best solution under these circumstances (especially if the dethrottle chip does not cure it completely), is to have the worn bushes on the throttle bodies replaced. As JSG said, you can get this done by Dreadnought or SFR Engineering (about £300 + VAT I believe). James can probably tell us more as I think his car was the first that SFR did with this.
'Yahoo' got his done by Dreadnought and has also been very pleased with the smoothness it brought to the engine. Incidentally, a 3.6, as your Tam is most likely to have ( I think there have been a few unofficial 4.0s) should inherently be a smoother engine than a 4.0 Speed Six.
If the throttle bodies are worn, the pots give out wildly differing voltages to each other so the ECU finds it difficult to know what position they are in. The reaction to this can be 'desensitised' using the dethrottle chip. Most people report that engines run more smoothly after this little upgrade, and I can't say I have felt any difference in terms of performance. However, the best solution under these circumstances (especially if the dethrottle chip does not cure it completely), is to have the worn bushes on the throttle bodies replaced. As JSG said, you can get this done by Dreadnought or SFR Engineering (about £300 + VAT I believe). James can probably tell us more as I think his car was the first that SFR did with this.
'Yahoo' got his done by Dreadnought and has also been very pleased with the smoothness it brought to the engine. Incidentally, a 3.6, as your Tam is most likely to have ( I think there have been a few unofficial 4.0s) should inherently be a smoother engine than a 4.0 Speed Six.
Now i had a very similar problem, and it stumped the RAC it turned out to be a faulty HT lead that was only a couple of years old so something i did not check, apparently the heat generated under a TVR bonnet wears these quickly, I had also dropped a spark plug before fitting so the usual diagnostics went out the window as the car was only firing on 4 cylinders sometimes, I would recomend changing spark plugs and ht leads then some good quality injection cleaner and if this doesnt work i will eat my hat, I tried to diagnose by changing 1 plug at a time and this did not show up anything as 2 plugs were wearing out, If you live localish i will come over and swap my plugs and leads over for you to try, But in the meantime some injecter cleaner, Happy hunting
Thank you very much for the suggestions thus far guys
I will ask the garage next week to change the plugs and HT leads, and also fix the injector cap that is 'taped up'! I will also ask them to look at the throttle bodies for signs of wear, hopefully, this will cure the prob, if it's not too expensive, I will have enough for a close ratio gearbox (on the proviso that I quit smoking!!! 
)
I will ask the garage next week to change the plugs and HT leads, and also fix the injector cap that is 'taped up'! I will also ask them to look at the throttle bodies for signs of wear, hopefully, this will cure the prob, if it's not too expensive, I will have enough for a close ratio gearbox
(on the proviso that I quit smoking!!! )TUS 373, sounds spot on to me.
Chris, if you get the ECU wired up to a laptop at the garage, they'll be able to see straight away whether it's trying to fudge the fuelling of the car 'cos of the worn throttle bodies. Similarly, they can balance them in a few minutes, too, if that's all it is. I had the SFR bodies put on mine - £300-ish all in. The problem with the standard ones is that they don't have a bush at all (as far as I can remember) - the 3rd party upgrades do.
It could well be anything else mentioned, or something entirely different, too, of course.
Chris, if you get the ECU wired up to a laptop at the garage, they'll be able to see straight away whether it's trying to fudge the fuelling of the car 'cos of the worn throttle bodies. Similarly, they can balance them in a few minutes, too, if that's all it is. I had the SFR bodies put on mine - £300-ish all in. The problem with the standard ones is that they don't have a bush at all (as far as I can remember) - the 3rd party upgrades do.
It could well be anything else mentioned, or something entirely different, too, of course.
Cheers , What do need to ask for exactly regarding the throttle bodies, could you paste a link for me?, I am assuming they're the same for both 3.6 and 4 litre varients?
Cheers
Chris
Have just rang SFR, and they need the car to alter the throttle bodies, saying they machine the exsisting ones, or something!, but Cheshire is a little too far really! bummer
>> Edited by chris watton on Thursday 29th July 17:59
, What do need to ask for exactly regarding the throttle bodies, could you paste a link for me?, I am assuming they're the same for both 3.6 and 4 litre varients? Cheers
Chris
Have just rang SFR, and they need the car to alter the throttle bodies, saying they machine the exsisting ones, or something!, but Cheshire is a little too far really! bummer
>> Edited by chris watton on Thursday 29th July 17:59
chris watton said:
Cheers
Cheers
Chris
I believe the 3.6 and 4.0 will be the same. Just ask to have the balance checked and adjusted if necessary. As above, its a simple procedure that can be diagnosed rapidly from the ECU input voltages from the throttle assembly.
Standard throttle bodies will wear again, given time. Think there've been some stories on here of them only lasting a couple of thousand miles. 
(Can't confirm that, though)
Yeah, you do have to drop the car off for getting them done at SFR/Dreadnought. I would've gone for the Dreadnought ones myself, if it hadn't mean driving all the way up to Scotland/going to their only UK distributor (Hexham - as near to the Scottish border as an English Tiv dealer gets!!?!?)
In the end, my car was off the road for three weeks having it done, but that was an exception, as far as I know... Shane at SFR had a few problems getting them done.
Best just to see if there's something else wrong before resorting to this!
(Can't confirm that, though) Yeah, you do have to drop the car off for getting them done at SFR/Dreadnought.
I would've gone for the Dreadnought ones myself, if it hadn't mean driving all the way up to Scotland/going to their only UK distributor (Hexham - as near to the Scottish border as an English Tiv dealer gets!!?!?) In the end, my car was off the road for three weeks having it done, but that was an exception, as far as I know... Shane at SFR had a few problems getting them done.
Best just to see if there's something else wrong before resorting to this!
I will now wait and see what the conclusions are when I take it in Monday (have wrote a list of things to check for the garage! lol)
Shame about the uprated throttle bodies,9are there really no others local to me that doesn't do them??) I was under the misguided assumption that I could just ring up SFR, pay for the 6 throttle bodies over the phone, and have them delivered to me for Monday, ready for fitting! Silly me, nothing's that simple, especially in TVR land! lol
Visiting this site with you guys is I think just as important as the car service itself!
Shame about the uprated throttle bodies,9are there really no others local to me that doesn't do them??) I was under the misguided assumption that I could just ring up SFR, pay for the 6 throttle bodies over the phone, and have them delivered to me for Monday, ready for fitting! Silly me, nothing's that simple, especially in TVR land! lol
Visiting this site with you guys is I think just as important as the car service itself!
chris watton said:
I will now wait and see what the conclusions are when I take it in Monday (have wrote a list of things to check for the garage! lol)
Shame about the uprated throttle bodies,9are there really no others local to me that doesn't do them??) I was under the misguided assumption that I could just ring up SFR, pay for the 6 throttle bodies over the phone, and have them delivered to me for Monday, ready for fitting! Silly me, nothing's that simple, especially in TVR land! lol
Visiting this site with you guys is I think just as important as the car service itself!
Yeah, would be nice if it didn't involve having the car off the road! You try finding out how much a normal set are new from TVR, order them, and have those "modded", then shipped down to be fitted by someone local.
Best of luck!
Worn throttle bodies will show up as a slight hesitation while driving at a constant throttle speed of around 2500 rpm, much more noticeable on a longer drive for example sitting at 70-80mph on the motorway. It's a bit like you are driving into a headwind and the car is trying to overcome it. This can be helped by lubricating the bodies and ensuring your engine is properly balanced and set up.
If your car is misfiring and running very badly it will probably not be the throttle bodies unless they are really stuffed.
Replacement bodies contain roller bearings in the bushes rather than normal bushes which can wear slightly which causes the wrong fueling readings and hence the very slight engine speed variation.
A lot of people seem to confuse throttle bodies with throttle pots. To replace the throttle bodies is a big job and most dealers would not do it unless absolutely necessary. Throttle pots can be replaced in 10 minutes each and are cheap.
My Red Rose Tuscan has had the symptom mentioned in my first paragraph above since about 5000 miles, but is only annoying on a long trip and the engine runs beautifully when set up correctly and you forget about the throttle bodies. The factory did mutter about a fix for them back in 2001 but I gave up asking in the end.
In my experience the Speed 6 engine needs a tweek every 3000 miles and new HT leads at every service and tappets checked whenever the hot idle drops below 650 rpm.
And what a fantastic powerful wicked sounding engine it is......
cheers
Whitey
If your car is misfiring and running very badly it will probably not be the throttle bodies unless they are really stuffed.
Replacement bodies contain roller bearings in the bushes rather than normal bushes which can wear slightly which causes the wrong fueling readings and hence the very slight engine speed variation.
A lot of people seem to confuse throttle bodies with throttle pots. To replace the throttle bodies is a big job and most dealers would not do it unless absolutely necessary. Throttle pots can be replaced in 10 minutes each and are cheap.
My Red Rose Tuscan has had the symptom mentioned in my first paragraph above since about 5000 miles, but is only annoying on a long trip and the engine runs beautifully when set up correctly and you forget about the throttle bodies. The factory did mutter about a fix for them back in 2001 but I gave up asking in the end.
In my experience the Speed 6 engine needs a tweek every 3000 miles and new HT leads at every service and tappets checked whenever the hot idle drops below 650 rpm.
And what a fantastic powerful wicked sounding engine it is......
cheers
Whitey
J_S_G said:
Standard throttle bodies will wear again, given time. Think there've been some stories on here of them only lasting a couple of thousand miles.
I have heard similar storys regarding the throttle bodies.I had un-even running at certain RPM and thorght it may be the spindal wear due to mileage although it just turned out to be one of the throttle pot's.
Update on my hesitation prob,,,,, I emailed TVR Power yesterday and explained the symptoms. Dom emailed me back saying'
'This is no big problem your throttle pots are worn
We are closed for 2 weeks from 16th august until 31st august'
Phew, but when the hell can I get them looked at!!! lol
PS, the throttle pots are FORD parts!!!!!!!
>> Edited by chris watton on Wednesday 11th August 13:44
'This is no big problem your throttle pots are worn
We are closed for 2 weeks from 16th august until 31st august'
Phew, but when the hell can I get them looked at!!! lol
PS, the throttle pots are FORD parts!!!!!!!
>> Edited by chris watton on Wednesday 11th August 13:44
Gassing Station | Tuscan | Top of Page | What's New | My Stuff