High RPM Misfire?
Discussion
Hello peeps. Collected my Tuscan on Friday, well chuffed. It's a 2001 (X) in Olympic Blue with Magnolia hide & Prussian seat inserts and has done 5800 miles. I've noticed it hesitates momentarily at high rpm (between 6000rpm and redline) which seems like a slight misfire. The plugs wouldn't be wet, as it was only driven at the weekend when it was dry and it's just had the 6K service prior to collection. Any ideas what this could be, if not a misfire and how to resolve?
Appreciate any advice!
Cheers.
Appreciate any advice!
Cheers.
I still have the same problem on mine. It is going back to the Dealer tomorrow. So far they have replaced HT leads, checked plugs, adjusted throttle bodies, tried a new potentiometer, replaced lambda sensors, replaced engine management chip and I think that is it. It seems to make no difference if I run on Optimax or 95 Ron. Will let you know if the dealer manages to fix it this time.
Had the same prob with mine last year feels like the revlimiter cutting in found out the fault is the spindles on the throttle body’s.
Went to the dealer and had them changed, great but after a few months and some hard miles fault came back again.
Spoke to Claire and Brian at Dreadnought TVR about the problem and it was a problem they see the whole time. After a long chat they asked if i wanted to test their new T/Body's, sure i said at which point they showed me their new prototype t/body’s with roller bearings sleaved in to them which will eliminate spindle wear and vibration, very trick.
So next day brought car in ripped the factory body’s off and Claire fitted the new roller T/Body’s on, set the flows and away we went.
Well its now as smooth as an M3 six, pulls from 700rpm in 4th around town with no fuss or stuttering !!
You can even put the old ECU chip back and its smooth, responsive and ultra fast.
Dreadnought are the only TVR dealer on the planet to do this and production is now in full swing, in the mean time Claire at Dreadnought can be contacted on 01877 331099
>> Edited by YAHOO on Monday 12th May 21:07
Went to the dealer and had them changed, great but after a few months and some hard miles fault came back again.
Spoke to Claire and Brian at Dreadnought TVR about the problem and it was a problem they see the whole time. After a long chat they asked if i wanted to test their new T/Body's, sure i said at which point they showed me their new prototype t/body’s with roller bearings sleaved in to them which will eliminate spindle wear and vibration, very trick.
So next day brought car in ripped the factory body’s off and Claire fitted the new roller T/Body’s on, set the flows and away we went.
Well its now as smooth as an M3 six, pulls from 700rpm in 4th around town with no fuss or stuttering !!
You can even put the old ECU chip back and its smooth, responsive and ultra fast.
Dreadnought are the only TVR dealer on the planet to do this and production is now in full swing, in the mean time Claire at Dreadnought can be contacted on 01877 331099
>> Edited by YAHOO on Monday 12th May 21:07
Yahoo, please tell us more. My Tuscan 'hesitates' at constant throttle when held anywhere between 1800-2200 rpm. I spoke to the factory today who serviced the car just a few weeks ago. They said that all was well and that it was tuned OK. However, if this problem persists then they could "spend 4 hours trying to balance the butterflies". I don't think they are entomologists with small scales - but I don't know enough about fueling to fully comprehend what this would involve. Are you telling is that this is a superior set up that Dreadnought have invented themselves and can fit (albeit without TVR approval). How much, can anyone else do this, could it be a DIY job? Answers on a postcard please - I'm interested!
Thanks
Bryan
>> Edited by TUS 373 on Monday 12th May 21:28
Thanks
Bryan
>> Edited by TUS 373 on Monday 12th May 21:28
TVR5 said:
If 'judas' reads this thread, did the new HT leads sort your (similar) problem?
Still here lurking, work's been a nightmare so no posting 
Anyhoo - no the HT leads did not sort the problem, as I found when I went over to TMS to pick it up after they'd said it was sorted, got part way home and it started misfiring again
In the end they checked the valve clearances and found some were 'a bit tight' and now that's been sorted it's running fine.
Thank God I am not alone I have been a constant miss fire at 2200 revs. Been back to the factory many, many times and had everything changed!
Last Service took it to Jools @ Joospeed who had it 2 weeks and thinks it's an ECU mapping problem? He wanted to increase the minimum Lambda value from zero. Spoke to John Ravenscroft who would only suggest that the HT leads etc need changing!
Still runs like a bag of s@#te.....
Last Service took it to Jools @ Joospeed who had it 2 weeks and thinks it's an ECU mapping problem? He wanted to increase the minimum Lambda value from zero. Spoke to John Ravenscroft who would only suggest that the HT leads etc need changing!
Still runs like a bag of s@#te.....
IanF said: Thank God I am not alone I have been a constant miss fire at 2200 revs. Been back to the factory many, many times and had everything changed!
Last Service took it to Jools @ Joospeed who had it 2 weeks and thinks it's an ECU mapping problem? He wanted to increase the minimum Lambda value from zero. Spoke to John Ravenscroft who would only suggest that the HT leads etc need changing!
Still runs like a bag of s@#te.....
Ian,
My problem started at a high RPM around 4.5K but became most noticable around 2000 to 2500 as the problem grew. Do you notice a slight lurching when on the motorway at around 90mph as well?? If so it sounds identical to the problem I have just had resolved...
David Gerald TVR sorted mine out as I had purchased from them and it was under warrenty through them (and I hasten to add that they did it first time!)
Cheers
DC
I've spoken to quite a few people about the 'hesitancy' of my engine at around 1800-2400 rpm. The factory do not seem very interested - and I mentioned it to the at the time of the service a couple of weeks ago. They put a new chip into the ECU (possibly a dethrottle chip - but they did not give specifics) - if anything it is worse than before, but the engine seems up on power though down on smoothness.
Spoke to Claire at Dreadnought. Seems that the throttle body spindles could be another potential cause. As Yahoo put so well, if the spindles on the butterflies have worn, they do not operate smoothly. Any vibration/osciallation will cause (some of) the butterflies to open too much/little at the wrong point and the ECU will try to compensate - but can't. Result is rough running. It may be OK with a quick rebalance - but if the spindles are worn, its not going to help. Even new throttle bodies will wear in time and the problem can return. Dreadnought are stil developing their set up in conjunction with TVR where bearings are used (so don't wear). This sounds like a worthwhile upgrade when they are availble - and when the problem develops.
Other thoughts by those in the know are HT leads - which can give similar symptoms. Otherwise, failing all of this, the ECU may need remapping - and this sounds like a non-starter for one reason and another - that the map programme is fixed and cannot really be modified (AFAIK).
It'll be a couple of weeks until I can run the car down to a local expert on the subject (SFR Engineering, Stockport, Cheshire) - so I'll report back when I have more news on my own situation.
Spoke to Claire at Dreadnought. Seems that the throttle body spindles could be another potential cause. As Yahoo put so well, if the spindles on the butterflies have worn, they do not operate smoothly. Any vibration/osciallation will cause (some of) the butterflies to open too much/little at the wrong point and the ECU will try to compensate - but can't. Result is rough running. It may be OK with a quick rebalance - but if the spindles are worn, its not going to help. Even new throttle bodies will wear in time and the problem can return. Dreadnought are stil developing their set up in conjunction with TVR where bearings are used (so don't wear). This sounds like a worthwhile upgrade when they are availble - and when the problem develops.
Other thoughts by those in the know are HT leads - which can give similar symptoms. Otherwise, failing all of this, the ECU may need remapping - and this sounds like a non-starter for one reason and another - that the map programme is fixed and cannot really be modified (AFAIK).
It'll be a couple of weeks until I can run the car down to a local expert on the subject (SFR Engineering, Stockport, Cheshire) - so I'll report back when I have more news on my own situation.
Well, the car is in as we speak being roadtested to see what Walldonway TVR make of the misfire. Will let you guys know they reckon!
Oh, had the 15A ignition fuse go on me at the weekend but thanks to these forums knew which fuse it was straight away and how to remedy! Cheers guys (and girls...!)
Oh, had the 15A ignition fuse go on me at the weekend but thanks to these forums knew which fuse it was straight away and how to remedy! Cheers guys (and girls...!)
darty said: I still have the same problem on mine. It is going back to the Dealer tomorrow. So far they have replaced HT leads, checked plugs, adjusted throttle bodies, tried a new potentiometer, replaced lambda sensors, replaced engine management chip and I think that is it. It seems to make no difference if I run on Optimax or 95 Ron. Will let you know if the dealer manages to fix it this time.
Was it fixed then?
I had the same problem at Donni where it was missing at around 6500rpm and getting worse near the end of the day. Just picked the car up from Andy at APM who serviced it an mentioned two of the throttle bodys were way out but he thought the missing problem was a plug.
Took the car for a good drive yesterdy and problem gone - not to mention running like a dream and sounds wild after having the exhausts sleeved.
Would recommned Andy if your having a problem like this.
Took the car for a good drive yesterdy and problem gone - not to mention running like a dream and sounds wild after having the exhausts sleeved.
Would recommned Andy if your having a problem like this.
Just heard from the Dealer. Having tried everything recommended by the factory they have been unsuccessful in fixing the problem. 
I am now waiting to find out when the transporter is in the local vicinity to take the beastie back home to Blackpool. Anyone got any idea from experience, how long this may take to get fixed by the factory?
I am now waiting to find out when the transporter is in the local vicinity to take the beastie back home to Blackpool. Anyone got any idea from experience, how long this may take to get fixed by the factory? The problem is made worse by the way the ECU on the S6 operates. Each time they put the Lap top on it resets the ECU values. It would seem that the ECU sets the throttle values it self (unlike the AJP 8) So with my car it sets off great (after a service etc) then usually 3 days later starts with the typical poor running due to the ECU running the engine leaner and leaner?
Jools reckons if I run my car with a lap top attatched resetting the ECU every 1/4 of mile then it would solve the problem!
Jools reckons if I run my car with a lap top attatched resetting the ECU every 1/4 of mile then it would solve the problem!
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