Adaptive Mapping Issues
Discussion
Perhaps someone can shed light on my problem.....
My T350C starts running "Rough" between 1500RPM and 3000RPM making it jerky and awkward to drive, especially in traffic.
Several times I have had my adaptive maps reset by the dealer and lo and behold the car runs smoothly (problem goes away) for a few days and then gradually returns - although I do spend time in traffic I also drive hard on a regular basis as well - I could maybe understand if all I did was drive in traffic - from what I understand the engine management system "adapts" to the driving style (I may be wrong) I would also like to have the motor dyno-tuned (had my cats recently removed) but will this be a waste of money if the adaptive system changes the tuning profile anyway?
The car has had this problem since day one (the removal of the cats did not cause this) the local TVR mechanic is a bit in the dark and is quizzing the factory however perhaps someone out there has experienced the same issue and knows of a fix?
We have checked the Lambda sensors and the air-flow sensor and these are fine.
Any advice or comments will be gratefully recieved.
My T350C starts running "Rough" between 1500RPM and 3000RPM making it jerky and awkward to drive, especially in traffic.
Several times I have had my adaptive maps reset by the dealer and lo and behold the car runs smoothly (problem goes away) for a few days and then gradually returns - although I do spend time in traffic I also drive hard on a regular basis as well - I could maybe understand if all I did was drive in traffic - from what I understand the engine management system "adapts" to the driving style (I may be wrong) I would also like to have the motor dyno-tuned (had my cats recently removed) but will this be a waste of money if the adaptive system changes the tuning profile anyway?
The car has had this problem since day one (the removal of the cats did not cause this) the local TVR mechanic is a bit in the dark and is quizzing the factory however perhaps someone out there has experienced the same issue and knows of a fix?
We have checked the Lambda sensors and the air-flow sensor and these are fine.
Any advice or comments will be gratefully recieved.
mwtryan said:
....We have checked the Lambda sensors and the air-flow sensor and these are fine.
How could you check the air-flow sensor? SP6's don't have them do they
? The air mass is calculated from air temp, throttle angle and manifold pressure. Have they checked the throttle pots, as this can cause all sorts of problems?
I have just had my car back from a 12k service and my tamora does exactly the same(it didn't before) I took it back and they replaced the chip underneath the steering column, I drove home no problem. Drove it a few days later and the problems back.
I need to speakto them again but I dont think they know the answer!
Would you describe yours as occuring when you feather the throttle at about 2000rpm when coastng in traffic? or say when you are holding a gear at low revs, in a car park say in 1st or second gear?
>> Edited by higgy on Monday 12th September 21:10
I need to speakto them again but I dont think they know the answer!
Would you describe yours as occuring when you feather the throttle at about 2000rpm when coastng in traffic? or say when you are holding a gear at low revs, in a car park say in 1st or second gear?
>> Edited by higgy on Monday 12th September 21:10
mwtryan said:
The sensor that sits on top of the air filter housing as far as I'm told is the air sensor? At least that's what the local TVR mechanic told me (hey HE might be wrong - we're a long way from the factory).
If this is not the air flow sensor - what is it?
If this sensor sits dead center of the airbox facing the engine, and has two pins in the plug / sensor then it's the air temperature sensor.
Nothing to do with air flow.
My arguement about the throttle potentiometers still stands.....
nelly1 said:
[
My arguement about the throttle potentiometers still stands.....
there is some merit in the throttle pot theory, had mine changed last year after my car displayed the same symptoms as what you describe, and once replaced, it was perfect! These, I was told ny TVR Power 'realistically' last about 14K miles before they get worn (They are Ford parts, only around £80 for the pair) I have mine changed at every 12K service.
Er .... OK AIR ''Temperature'' sensor then, well whatever - checked out OK. Could be the throttle pots, what do you actually check for? Whats the procedure? The car is with TVR at the moment - maybe I can get an answer from you so he can look at it today / tomorrow?
What I don't understand is this: If the throttle pots ARE causing this surely that's a physical problem, if so why does the car behave itself for a day or 2 after re-setting the adaptive maps? A faulty part is a faulty part and surely no amount of electronic adjustment will make any difference - what do you think?
What I don't understand is this: If the throttle pots ARE causing this surely that's a physical problem, if so why does the car behave itself for a day or 2 after re-setting the adaptive maps? A faulty part is a faulty part and surely no amount of electronic adjustment will make any difference - what do you think?
chris watton said:
[
My arguement about the throttle potentiometers still stands.....
there is some merit in the throttle pot theory, had mine changed last year after my car displayed the same symptoms as what you describe, and once replaced, it was perfect! These, I was told ny TVR Power 'realistically' last about 14K miles before they get worn (They are Ford parts, only around £80 for the pair) I have mine changed at every 12K service.
I have to agree with throttle pots, these will cause lumpy running at low revvs in trafic.
mwtryan said:
What I don't understand is this: If the throttle pots ARE causing this surely that's a physical problem, if so why does the car behave itself for a day or 2 after re-setting the adaptive maps? A faulty part is a faulty part and surely no amount of electronic adjustment will make any difference - what do you think?
The fact is that the maps are adaptive ie. learning from the moment you reset them, and they are controlling the closed loop (part load / throttle) fuelling of your engine.
These maps are governed primarily by throttle position and HEGO sensor (Lambda) feedback, and IIRC, they are updated at regular intervals for different load sites.
If the table has to be 'built' before the module decides there is a fault, this could explain your engine's tendency to be ok for a while.
It could just be the well known phenomenon of faults disappearing the second the car gets near a garage
OK - think I get the picture and what you say does make sense, will have the throttle pots checked out. This is the second motor in the car (1st one blew up spectactularly at 3000 miles!) and has only done 2500 miles though. Can you tell me what to look for re: throttle pots and here's why, being a new dealership in SA the local knowledge is still relatively little on the S6 motor and information from the factory is sooo slooow, also we have noticed a certain reticence from TVR in admitting certain issues arising out of generic problems with this engine.
mwtryan said:
OK - think I get the picture and what you say does make sense, will have the throttle pots checked out. This is the second motor in the car (1st one blew up spectactularly at 3000 miles!) and has only done 2500 miles though. Can you tell me what to look for re: throttle pots and here's why, being a new dealership in SA the local knowledge is still relatively little on the S6 motor and information from the factory is sooo slooow, also we have noticed a certain reticence from TVR in admitting certain issues arising out of generic problems with this engine.
I reckon if you 'phone Austec (uk - 44 I think - 01293 531080) and speak to Paul explaining your predicament, he'll be more than happy to help
!!Expensive not an issue as the car is under warranty - plus TVR in SA are fabulous in their service - they are really trying and even give me the demo T350 as a "loaner" whilst they attend to mine.
The catalytic joints are fine, so are the leads, as I've said - this car is barely run-in, however have found some poor factory electrical connections duly sorted. No, I really think the throttle "pots" are the guilty party here, by the way, the name "pot" threw me as we call them throttle "bodies" here. Sean (TVR mechanic) is stripping the throttle pots for a re-set tomorrow and we will see if there's an improvement - will let you guy's know how we get on.
The catalytic joints are fine, so are the leads, as I've said - this car is barely run-in, however have found some poor factory electrical connections duly sorted. No, I really think the throttle "pots" are the guilty party here, by the way, the name "pot" threw me as we call them throttle "bodies" here. Sean (TVR mechanic) is stripping the throttle pots for a re-set tomorrow and we will see if there's an improvement - will let you guy's know how we get on.
There is a difference between the throttle potentiometers and throttle bodies, the throttle 'pots' are 2 little plastic encased Ford units, which fit either end of the throttle 'rail' (I think!), the 'Pots' control the opening and closing of the throttle bodies, and when the pots wear, the first symptoms are uneven running and stuttering acceleration, because the the female holes that hold the rail in place wear, causing the pots to get out of alignment.
I think! lol, amazing what a complete engine nimpty learns from owning a TVR!!!!!
>> Edited by chris watton on Thursday 15th September 20:07
I think! lol, amazing what a complete engine nimpty learns from owning a TVR!!!!!
>> Edited by chris watton on Thursday 15th September 20:07
Throttle bodies and throttle pots are different things.
There are 6 throttle bodies on a S6 enigine, one for each cylinder. They control the mixture of air / fuel entering the engine, like a carb. All the throttle bodies are joined by a common throttle linkage, which is connected via a cable to the throttle / loud pedal
The pot, (short for potentiometer), is a little black electrical device that tells the ECU at what position the butterfly is within the throttle bodies. there are 2 of them on an S6, one at each end of the throttle linkage.
I had mine changed as a preventative measure at the the 12k service as they are know to be a week part. The cars runs very smoot now compared to pre service.
There are 6 throttle bodies on a S6 enigine, one for each cylinder. They control the mixture of air / fuel entering the engine, like a carb. All the throttle bodies are joined by a common throttle linkage, which is connected via a cable to the throttle / loud pedal
The pot, (short for potentiometer), is a little black electrical device that tells the ECU at what position the butterfly is within the throttle bodies. there are 2 of them on an S6, one at each end of the throttle linkage.
I had mine changed as a preventative measure at the the 12k service as they are know to be a week part. The cars runs very smoot now compared to pre service.
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