How do I get positive adaptives???
Discussion
What are the throttle pot readings showing? They may be too high.
The base fuel map was set up against a particular flow of air with the TPots showing a particular percentage opening.
What you need to do is get a TPot reading that puts the ecu onto a map site that is delivering enough fuel for the air flowing but no more.
If both banks are showing the same tpot and adaptives then they are reasonably balanced.
But if both are always negative adaptives then the base map is delivering too much fuel.
As the sites increase around 1,000 rpm the fuel increases. So decreasing both tpot readings (but not changing the physical opening of the throttle butterflies) will move the idle up to a lower map site delivering less fuel. So the adaptives shouldn't go too negative.
IIRC the TVR diagnostics suggest 18% but Trackcar always sets a 4.2 at around 16.9 which gives adaptives close to zero and a decent idle.
The base fuel map was set up against a particular flow of air with the TPots showing a particular percentage opening.
What you need to do is get a TPot reading that puts the ecu onto a map site that is delivering enough fuel for the air flowing but no more.
If both banks are showing the same tpot and adaptives then they are reasonably balanced.
But if both are always negative adaptives then the base map is delivering too much fuel.
As the sites increase around 1,000 rpm the fuel increases. So decreasing both tpot readings (but not changing the physical opening of the throttle butterflies) will move the idle up to a lower map site delivering less fuel. So the adaptives shouldn't go too negative.
IIRC the TVR diagnostics suggest 18% but Trackcar always sets a 4.2 at around 16.9 which gives adaptives close to zero and a decent idle.
mikesr said:
What are the throttle pot readings showing? They may be too high.
The base fuel map was set up against a particular flow of air with the TPots showing a particular percentage opening.
What you need to do is get a TPot reading that puts the ecu onto a map site that is delivering enough fuel for the air flowing but no more.
If both banks are showing the same tpot and adaptives then they are reasonably balanced.
But if both are always negative adaptives then the base map is delivering too much fuel.
As the sites increase around 1,000 rpm the fuel increases. So decreasing both tpot readings (but not changing the physical opening of the throttle butterflies) will move the idle up to a lower map site delivering less fuel. So the adaptives shouldn't go too negative.
IIRC the TVR diagnostics suggest 18% but Trackcar always sets a 4.2 at around 16.9 which gives adaptives close to zero and a decent idle.
Both my TP readings are 13.0 and this seems to give the best adaptive readings when the idle screw is fully wound down, about -20. I can get a reasonable idle of about 950 rpm with the throttle stop popped up a bit and the adaptives both at around -22.The base fuel map was set up against a particular flow of air with the TPots showing a particular percentage opening.
What you need to do is get a TPot reading that puts the ecu onto a map site that is delivering enough fuel for the air flowing but no more.
If both banks are showing the same tpot and adaptives then they are reasonably balanced.
But if both are always negative adaptives then the base map is delivering too much fuel.
As the sites increase around 1,000 rpm the fuel increases. So decreasing both tpot readings (but not changing the physical opening of the throttle butterflies) will move the idle up to a lower map site delivering less fuel. So the adaptives shouldn't go too negative.
IIRC the TVR diagnostics suggest 18% but Trackcar always sets a 4.2 at around 16.9 which gives adaptives close to zero and a decent idle.
Why would the ecu been bunging in so much fuel?
MB
hmmm OK so not high TPots 
Either
1. ecu is bunging in loadsa fuel or
2. less air coming in than should be
1 could be caused by a faulty sensor reading causing the ecu to apply a lot of fuel via one of the compensation maps
Have you run logged of the ecu to see what the water temp, air temp, battery voltage etc are doing?
2 could be blocked air filter or collapsed hoses or some such
Either
1. ecu is bunging in loadsa fuel or
2. less air coming in than should be
1 could be caused by a faulty sensor reading causing the ecu to apply a lot of fuel via one of the compensation maps
Have you run logged of the ecu to see what the water temp, air temp, battery voltage etc are doing?
2 could be blocked air filter or collapsed hoses or some such
trackcar said:
Are you chasing a set of adaptives close to zero or are you trying to rectify a driving fault? If your car drives well asit is then I wouldn't bother adjusting anything, it might be set that way for a reason ..
Trying to rectify a driving fault. It drives like it has too much fuel coming in. It coughs a splutters at low revs and I have a few too many large explosions booming from the exhausts. Whatever I have tried I can't seem to reduce adaptives to anywhere near zero or positive.MB
hmm .. well cerbies are a bit smelly anyway .. they have lots of lift on overlap, and sky high hydrocarbon readings which the cats are only good at cleaning up if in perfect condition.
Pops on teh overrun are due to a WEAK mixture not a rich one .. if you run rich you get no pops at all, so are you sure things are as bad as they appear?
It might be you're barking up the worng tree so i suggest taking the car to your nearest cerbera speciallist (note not general TVR indie/specialist, but Cerbera specialist) and see what they reckon.
Pops on teh overrun are due to a WEAK mixture not a rich one .. if you run rich you get no pops at all, so are you sure things are as bad as they appear?
It might be you're barking up the worng tree so i suggest taking the car to your nearest cerbera speciallist (note not general TVR indie/specialist, but Cerbera specialist) and see what they reckon.
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