Tamora engine issue

[padc1]

Bare with me while I try and explain the issue

The engine seems to hesitate when is at low rpm (between 1500-2500) it only happens when the throttle is barely open
Every where else in the rev range is fine and it's fine when the throttle is opened a little more

Let's say I'm in slow moving traffic at 30mph in 2nd gear with the throttle at a constant and low rpm it feels like it has a misfire and it hesitates but as soon as I apply a little more throttle and rpm it's fine

It asked my Tvr garage to look at it at the last service last year and after checking on the diagnostic machine they couldn't find any faults

The throttle bodies were checked and something was replaced but the problem hasn't improved

It's going in for this years service in a weeks time so if anyone has any idea please let me know

[Milky400]

Throttle body bushes maybe?

[phillpot]

padc1 said:

if anyone has any idea please let me know

Find a garage that can sort it rather than say "nothing wrong"?

Did they come out on the road with you so you could show them the issue?

[Incognegro]

My failsafe with a speed six engine so far is give Dom at Power a call. Im sure they will dee you good.

[Andy_mr2sc]

Does it ever have a hiccup at ~6200rpm only on wide open throttle?

[Englishman]

I've had four S6 engined cars and just one has exhibited this exact issue so I am very interested in the outcome. To me the symptoms suggest air getting in somewhere other than through the throttle butterflies, but I’ve had the gaskets changed (to Powers) and the throttle body bearings changed, but still does it!

[potash4]

I had a similar issue, not as noticeable as you described but it was the lambda sensor earth. Apparently it's a common fault.

[potash4]

See this for more info http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[padc1]

potash4 said:

See this for more info http://www.pistonheads.com/gassing/topic.asp?h=0&a...

That's the exact same symptoms so thanks very much I'll pass this on Dan at Taylor TVR when it's in for its service next week and let's hope it's fixed ready for the Summer

[padc1]

someone has suggested checking the valve clearances
Could this be the cause of the symptoms ?
I would have thought there would be a problem all accross the Rev range if they were out

[Incognegro]

My memory has just been jogged. When I was getting my dads Cerbera S6 back up to standard it had an issue like this at low and high end. Check the thermal pads. Again Power sorted this before a rebuild and things improved until I bit the bullet as 2 cylinders were out

[chris watton]

Intermittent lambda sensor (intermittent means it's not easy to diagnose, as I found out..) or throttle pots? If faulty, these two will most certainly make the engine stutter.

[padc1]

That's just it its not intermittent
It's there all the time

[Bobhon]

I would have thought if it's there all the time then any competent TVR garage should be able to hook it up to their computer and see what is causing it?

[Englishman]

Mine still does it after valve clearances have been adjusted a number of times. It's become one of those things I just live with, but I'd still like it fixed. Will be really interested to know how if Dan Taylor fixes it!

[padc1]

Englishman said:

Mine still does it after valve clearances have been adjusted a number of times. It's become one of those things I just live with, but I'd still like it fixed. Will be really interested to know how if Dan Taylor fixes it!

I'll have an update on Friday !
I know what you mean when you say you live with it but it's spoiling the car for me
Everything else is spot on and I love it

[shep1001]

If you have a lead & the diagnostics software plug it in and have a look at the lambda traces, throttle pot balance & the ignition trace that might point to the issue(s)

[T40ORA]

Nip out to Woody at TVR101.

[padc1]

Collected the car today and it's running a dream
All the symptoms that I described in my opening post have been sorted and I'm over the moon with the results
Everything that you need to know is explained better than I ever could in this link

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Thank you !

[Englishman]

Great news, so earthing the Lambda sensors seperately fixed it? Do you have 3 or 4 wire versions?