low rev pull back - anything to panic about

[tvr totty]

just want to use the benefit of all your wisdom on this people, know there has been items on high rev misfires, and after reading a few replies to the engines that are failing, think i have become paranoid, words of reassurance please

from cold in 2nd gear between 15 - 25mph (yes i know that is probably unheard of in a tuscan, its thanks to the 2 speed cameras as i start my journey to work each day!!) if you are not accelerating, but keeping constant speed you can feel her pulling back, the same applies in 3rd between 30-40pmh, you can accelerate through it, but if you are stuck behind yet another bloody tractor doing this constant speed she pulls back throughout. have felt this too when poodling along between 60 and 70, service is 2000 miles away and the dealer kindly gave us a years warranty (car is oct 2001). don't want to panic unnecessary, but don't want to do any damage??

thanks xx

[Dai Capp]

Sounds very similar to the problem I'm having...

When it happens, see if your revs are around 2300 to 2600 rpm. Also see if the same symptoms occur at around 3400 to 3800 in fifth (it'll be 90mph + so make sure your not near scameras!).

Try holding at a constant throttle to see if the problem continues. You should feel hesitation as if you are lifting off the throttle even though you're not.

If so I'll be able to enlighten you on July 11th as I'm at the factory on 10th to have it sorted. So far I've had new throttle pots, new throttle bodies, new leads and plugs. Haven't had the valve clearances done, which is also said to cure the problem, as the factory want to see the car first.

Hope this helps in diagnosing the problem further, if these are the symptoms you see hold on for 11th July! Incidently, my dealer has not indicated that the car shouldn't be driven, just use a bit of mechanical sympathy, ie find revs where it doesn't lurch and stick to them...

Cheers

DC

edited to say I've just reread your post and I'm pretty confident we share the same issue. If it makes you feel any more relaxed, I'm not expecting a rebuild...

>> Edited by Dai Capp on Friday 4th July 13:54

[ghosty o'shark]

Sounds exactly the same as mine. I had it serviced a few weeks ago and it turned out that both throttle pots (whatever they are) were knackered. This was only highlighted after the the engine had been tuned and then was taken for a test drive. I hate that "is it pulling back or is it just me?" feeling. In still have major engine issues but the one I have just described seems to be cured.

[Dai Capp]

ghosty o'shark said:

Sounds exactly the same as mine. I had it serviced a few weeks ago and it turned out that both throttle pots (whatever they are) were knackered. This was only highlighted after the the engine had been tuned and then was taken for a test drive. I hate that "is it pulling back or is it just me?" feeling. In still have major engine issues but the one I have just described seems to be cured.

New throttle pots cured mine for around 500 miles but it returned, that was when new throttle bodies were prescribed, they managed 100 miles.

Hope you get your major issues sorted pronto...

Fun in Tuscan land isn't it!

DC

[tvr totty]

thanks peeps, at least with a tvr you are never alone

will wait for verdict on 11th july, then go from there, thanks for that reassurance, keep me posted

xx

[basil brush]

Mine is doing a similar thing too. It's going into TMS for a service on Monday so will let you know if I find anything out.

Marcus

[T88CAN]

Guess what? Ditto had mine diagnoised as "a short between Lamda sensor and ECU" by TVR power nothing major have warranty? will have it looked at at next service power steering belt now sqealing on half lock!! the misfire obviously does n,t effect power to much ask the owner of the 996 turbo Porker (if he ever shows his face again)

[swordfish]

Sounds like the same as mine's doing too, though mine is at about 3000-3200 rpm in most gears.. Felt like the sparks or petrol supply was iffy at those revs.
Took it to the dealer for it about 6 weeks ago... After some laptop fiddling it was sorted.

It's now back again so it's going back for a better fix this time I hope.

Will post with details once it's sorted.

Martin

[Dai Capp]

As promised...

According to the factory they all do it its just some are worse than others. 4 litre speed six Cerbies don't do it as they have a different purge system apparently.

Anyway, they balanced the throttles, cleaned the plugs which will need replacing, I might need to have an oil consumption problem looked at and I may have a worn finger follower. Lots of mights and maybes.

The truth of the matter seems to be that if you have a 4 litre car you'll never be shot of the problem, mine appears to be as before after four hours of factory fettling.

So they may be able to reduce the lumpiness but not clear it totally.

Cheers

DC

[andyvdg]

Excuse my ignorance, but what is a "purge" system ?

Cheers,

Andy.

[anonymous-user]

tvr totty said:

thanks peeps, at least with a tvr you are never alone will wait for verdict on 11th july, then go from there, thanks for that reassurance, keep me posted xx

Definitely sounds like the throttle pots.
Don't worry, they're cheap and easy to balance/replace.

[Dai Capp]

andyvdg said:

Excuse my ignorance, but what is a "purge" system ? Cheers, Andy.

It's all to do with purging petrol vapours into the carbon cannister as I understand it. Still trying to work out how this could make a car run rough unless it is having a detrimental effect on fuel supply, ie the purge system is chucking some neat fuel into the carbon can and forcing the engine to run a bit lean.

I wish I was cleverer at this point!

Would agree with Bandit that the throttle bodies helped the 'misfire' - just make sure that they are fettled regularly until they are bedded in. However they certainly did not cure the problem for me...

Cheers

DC

[basil brush]

Mine is no better either after TMS having a look. They said that the throttles were a long way out and setting them seemed to have cured it. The funny thing about mine is that if you let it sit on tick over for a while the misfire clears for a bit and then returns after a couple of miles.

[s1nrr]

Mine too......about 3800 revs when on the motorway .....my S6 Cerbera never did it.................

Regards

Danny

[Nick Elliott]

Have never had this issue and have only had throttle pots balanced at routine services, has always reved up to point where all three light flash with no problems.It seems very strange to me that some have this issue & others don't.

Nick

[basil brush]

Mine didn't have it when I bought it about 2 months ago, but developed the problem fairly suddenly a few weeks ago. I can't understand why leaving it ticking over would temporarily cure it.

[YAHOO]

Just to say i have had all your symptons on my car when i first got it and tried all the usual suspects.
The only fix to all your problems {miss fire,pulling back,stuttering,crap idle and lumpiness is quite simple get Dreadnought TVR to fit their throttle bodys and you will be amazed. I have had my t/bodys on now for a year and 6 months and only had them tuned once in that time period ,and if you now my car you will know just how quick and smooth it is.

[St george]

Mine too. It was quickly sorted though. the cause was water in the 2nd spark plug seat. It also Knack>>> the Ht cable.

[badger748]

Mines has had this same problem since birth and has had various things done, including adjusting the throttle pots about 4 times.

Currently back at factory for a 'fix' including multitude of other issues, stemming from poor build.

Will post outcome when/if I get it back.

Lee

[tvr totty]

thanks everyone, car goes in for 6000 mile service in about 3 weeks, to check all the bits and pieces mentioned above, are we talking a couple of days - just that i use the beasty everyday for work and the less time off the road the better

xx