Characteristic or service required ?

[KPW894]

I'm relatively new to Tuscan ownership (4 weeks) and have only covered a few miles, but I find it very difficult to drive the car smoothly. At slowish speeds (30-40 mph)it seems that the throttle works almost like and on/off switch making progress quite jerky however gentle I am with the throttle pedal. I seem to be changing gear more than necessary to overcome the problem, if it is a problem. I'm curious to know whether this is a characteristic of the Tuscan/Speed6 or whether it needs a service. Current mileage is 17,500. Last service was carried out by Offord at 16,850 miles on 16/07/11 (6,000 mile service) and the previous service to that was again by Offord at 16,100miles in June 2010 (12,000 mile servce including tappets.)

Any thoughts or recommendations welcomed.

Thanks.

Kieron.

[Robertjp]

That certainly isn’t a nice or typical characteristic.

It sounds like its mechanical, could be a few things. Could be the throttle cable sticking, throttle bodies, either the spindles, butterfly valves etc. It could also be down to the adjustment of the throttle bodies / fuelling, which could be causing it to ‘bog down’ due to poor afr at low RPM and therefore requiring significant throttle to pick back up. They are just the things i can think of right now, there will be others.

Either way, i would advise caution in driving to be honest until you can get it to a specialist, if your throttle sticks open it could be very dangerous!

The throttle should be very responsive and smooth even from idle...except when cold where they tend to be a little lumpy.

[Laser Sag]

I would be asking the servicing garage why the drive has become so poor after only 750 miles and politely suggesting they might want to do something about. Offords has had a change in management team recently so will hopefully be keen to provide a good service to a customer to help improve what they know has become a poor reputation of late.
Phil came along to the last Cambs car club meet to promote Offords so I would suggest you try havinga chat with him and see what recommends.

Edited by Laser Sag on Monday 12th March 18:20

[TheGroves]

KPW894 said:

I'm relatively new to Tuscan ownership (4 weeks) and have only covered a few miles, but I find it very difficult to drive the car smoothly. At slowish speeds (30-40 mph)it seems that the throttle works almost like and on/off switch making progress quite jerky however gentle I am with the throttle pedal. I seem to be changing gear more than necessary to overcome the problem, if it is a problem. I'm curious to know whether this is a characteristic of the Tuscan/Speed6 or whether it needs a service. Current mileage is 17,500. Last service was carried out by Offord at 16,850 miles on 16/07/11 (6,000 mile service) and the previous service to that was again by Offord at 16,100miles in June 2010 (12,000 mile servce including tappets.)

Any thoughts or recommendations welcomed.

Thanks.

Kieron.

Hi Keiron,

It could be one of a number of things but there are some less expensive things to try first. My Mk1 Tuscan did exactly as you descibe at one point. The solution was the Throttle Potentiometers (throttle pots) They do get prone to needing to be replaced and aren't a service item so get overlooked a fair bit.

He's the link to Dom's website, http://www.tvrpower.co.uk/store/slug/throttle-pote...

If its this causing your problem, it'll be an instant fix and not a pricey one.

Mike

[Zippee]

Is the actual pedal smooth to press down when the engines off? If not it may be all linkages need greasing or it may be an indication the throttle cable is fraying and on its way out. Did you buy from Offords? If so I'd suggest they sort it for you, though personally they're not a garage I'd use.
Where abouts in Suffolk are you? Is Downham Mkt reasonably close by? If so theres an excellant TVR mechanic shortly to be starting up on his own there following many years at a well known and respected Indie.

[Laser Sag]

Zippee said:

Did you buy from Offords? If so I'd suggest they sort it for you, though personally they're not a garage I'd use.
.

I have to agree with you Tony, was perhaps trying to be too politically correct, not like me at all

Could possibly give Schole Engineering in Diss a try, I believe they have a decent reputation.

[coco79]

Is it a DIY job replacing the throttle pots? I have what seems a similiar issue..but keen to start doing things myself, but am always a bit nervous!

[Robertjp]

Throttle pot replacement is pretty straighforward, but you do need software to reset throttle pot positions and adaptive maps afterwards.

I also needed to make a gasket as the throttle body spindles were marginally longer than ideal... and this made the throttle pot very difficult to rotate, a gasket gave a bit more clearance and sorted out the mechanism

[blueg33]

Same problem in mine was a sticky throttle cable. New cable fixed it.

[KPW894]

Thanks for all the responses. In the end I called Dom and he suggested the sensible thing to do would be to plug it in to a laptop and attempt to diagnose the problem properly. So, I've got a cable on order and am currently reading through the previous threads covering this topic.

Any advice or pointers are welcome. I've downloaded the software and have read through the manual.


Thanks.

Kieron.

[Laser Sag]

Zippee said:

Is the actual pedal smooth to press down when the engines off? If not it may be all linkages need greasing or it may be an indication the throttle cable is fraying and on its way out.

Kieron

As Tony has said have you checked out the throttle smoothness when either switched off or when stationary? If it is jerky then it would probably suggest a mechanical component needs attention.
Where abouts are you in Suffolk?

With regard to the software side of things best bet is to try to check it when Dom is likely to be about as a call to him while you can pass on readings will probably have an answer much quicker.
Kev

[KPW894]

Hi Kev - I'll do as you suggest and speak to Dom when I get the laptop plugged in.

I live just south of Bury St.Edmunds and work in Cambridge.

Thanks.

Kieron.

[KPW894]

I've ordered the dianostic lead...should I be concerned that I've got two blue and one black wire going to my remote ecu connector?

Having read other threads on this subject I thought these should be different colours?

Thanks.

Kieron

[Cliffedge]

Try contacting Kerridges in Needham Market they're a lot nearer to you than Offords, and used to be a TVR main dealer but still work on TVR's, see link; http://www.kerridges.co.uk/.

[Curdster]

I have the same issue and want to diag before the service.
I have 3K used HT leads, so possibly not the issue. The jerkiness happens with constant throlle, so I don't suspect the linkages or sticking cable, so what next? Coil or Throttle Pots? If TP's which colour do I need and how many of them?

[Robertjp]

Curdster said:

I have the same issue and want to diag before the service.
I have 3K used HT leads, so possibly not the issue. The jerkiness happens with constant throlle, so I don't suspect the linkages or sticking cable, so what next? Coil or Throttle Pots? If TP's which colour do I need and how many of them?

That actually sounds like throttle bodies, once the spindles wear, at constant throttle you get hesitation, most easily detectable in high gear at constant speeds. Its the butterfly valves moving if this is your cause. Spindles are typically worn from 30k miles onwards from my research and experience. The latest cars had bushed throttle bodies to fix the issue, early ones are steel spindles in aluminium throttle bodies, not an ideal mix!

Be carefult replacing your throttle pots alone if this is contributing, they will simply fail again albeit a lot quicker!

When was your car last serviced? If its gone out of tune quickly that could also be an indication of the same.

[Curdster]

Rob thanks for the advice. I will therefore get the service done and then see what the running is like. It only seems noticable after a longer run say 2 hours in, rather than straight away. Do you have any idea how much a new set of Throttle Bodies are likely to cost?

[coco79]

New spark plugs, HT leads and fuel filter sorted mine..running sweet

[JimmyZZ]

Synchronize throttles and reset adaptives.
Changed the behaviour of mine completely.
Did it myself btw. Not a very big deal.

[JimmyZZ]

Synchronization following the order in the picture in this German forum
http://www.tvr-forum.de/viewtopic.php?f=16&t=2...
The first screw sets idle too.
Should be self explaining when you look at the picture.

Just be careful and do not confuse the adjustment of #4 throttle and #1 throttle and idle!!

You just need a carburettor synchrometer which you can easily find on eeekbay.

RESET the throttle pots when it is done!