Lambda sensors
Discussion
You need to retain the lambda sensors and keep the tune you currently have. If you switch to the green map, you dont know if TVR modified it (unlikely), so you will need a remap or tornado chip (all these chips have the correct engine tune across both maps). Running the catalysts map is only an issue if your car shunts, as the non catalysts map can be made to run a bit richer that helps reduce shunting. Both maps produce the same peak power. If makes no differences to the catalysts fuel map set up with or without physical catalysts, it will still run quite happily without them.
As your 430 is registered May 93 I don't see how you have cats as I think it was August 93 that cats were made compulsory. Are there any other other 400/430's that are catted?
It would be worth changing the tune resistor to a green (non cat)and putting the deact Y piece on and see how you go. Guess you'd have to disconnect the lambda sensors but not sure, as I believe the green resitoir ignores them anyways.
Be interested to see what the difference is.
FFG
It would be worth changing the tune resistor to a green (non cat)and putting the deact Y piece on and see how you go. Guess you'd have to disconnect the lambda sensors but not sure, as I believe the green resitoir ignores them anyways.
Be interested to see what the difference is.
FFG
grngriff said:
Hi
I think it was a export car, as the first 6 service stamps are from a Spanish or Italian garage,I thought cats were introduced in
Jan 93.
The chassis is stamped dec 92 so might get away with decatting it come mot time,
thanks guys for your input
Pete
You may be right on the cat date as I thought it was when the registrations changed which was 1st August.I think it was a export car, as the first 6 service stamps are from a Spanish or Italian garage,I thought cats were introduced in
Jan 93.
The chassis is stamped dec 92 so might get away with decatting it come mot time,
thanks guys for your input
Pete
Checked last years list and can't see another pre 500 1993 car - they are all 1992.
Why the long delay between making the chassis and being registered. Doesn't tally up.
FFG
Not Griffith but I thought I mention I was successful in changing the tune on my Range Rover LSE 4.2 -93 by modifying the tune resistor. I located it right hand of the ECU. It ran Blue tune (4.2 + cats) but my exhaust only have lambdas without cats. The Range is an import from Belgium where it apparently was ok to run w/o cats. Here in Sweden it was mandatory on all cars since 1988 but import vehicles get exempts. I read without cats it could run leaner in yellow tune (same as blue but no cats). I soldered another 1.8 Kohm resistor in parallel, yields half the resistance, which results in the Yellow tune. I verified using ECUMate that it now runs yellow.
But to my question; I read in the RAVE manual that later chassis uses a later ECU and does not use the tune resistor ?. I am not sure what is the case there; anyone know ? With such a later ECU what kind of tune mode would be used ? My 93 LSE is way past that serial. Anyway ECUMate tells I am running yellow now. I will check if I notice any difference adjusting CO on the AMF sensor. I heard mentioned in Blue tune that CO setting is ignored ? I am after having it run leaner on idle and not spew out too much smelly gases when cold. I have new O2 sensors.
Tune resistor before mod (blue/1800 ohms)
Identical resistor in parallel means half the resistance (=yellow tune)
Crimp hose applied
ECU Mate indicates yellow tune (thanks Steve for this great tool !)
The following text is found in the RAVE manual:
NOTE: Vehicles after VIN No 451518 are fitted with a new ECU, Part No. PRC 8747 to replace PRC 7081. This ECU no longer requires the tune select resistor, which is therefore deleted.
Would that note apply to NAS vehicles only ?
Is there cases where a PRC7081 is preferable over a PRC8747 ?
But to my question; I read in the RAVE manual that later chassis uses a later ECU and does not use the tune resistor ?. I am not sure what is the case there; anyone know ? With such a later ECU what kind of tune mode would be used ? My 93 LSE is way past that serial. Anyway ECUMate tells I am running yellow now. I will check if I notice any difference adjusting CO on the AMF sensor. I heard mentioned in Blue tune that CO setting is ignored ? I am after having it run leaner on idle and not spew out too much smelly gases when cold. I have new O2 sensors.
Tune resistor before mod (blue/1800 ohms)
Identical resistor in parallel means half the resistance (=yellow tune)
Crimp hose applied
ECU Mate indicates yellow tune (thanks Steve for this great tool !)
The following text is found in the RAVE manual:
NOTE: Vehicles after VIN No 451518 are fitted with a new ECU, Part No. PRC 8747 to replace PRC 7081. This ECU no longer requires the tune select resistor, which is therefore deleted.
Would that note apply to NAS vehicles only ?
Is there cases where a PRC7081 is preferable over a PRC8747 ?
Edited by gunnarLSE on Friday 26th April 04:04
Dont get too hung up on part numbers- I think(??) the ability to enable or disable the tune resistor is part of the Eprom data that can be plugged out anyway. On NAS ECU's even fitting different tune resistors directly to the ECU pins (as there is nothing in the loom) wont change the map.
Thanks I´ll take a look at the ECU part no. What is the best way to determine if the ECU ignores the tune resistor ? In fact while I´m at it
I will pull the ECU and take a peek inside to check if all is stock. In my case the resistor was found in the loom as normal.
Vehicle is SALLHBM34KA631324.
I will pull the ECU and take a peek inside to check if all is stock. In my case the resistor was found in the loom as normal.
Vehicle is SALLHBM34KA631324.
Edited by gunnarLSE on Friday 26th April 10:55
FlipFlopGriff said:
AFAIK there are a number of post 01/08/92 registered (to end of 92) Griffs without cats, in fact all seem to be 430's.
Maybe it was the build date not the registered date and the chassis dates were declared as pre August 1992??
FFG
IIRC TVR stock piled a load of Chassis 'in preparation' for the impending cat rules, so I believe the build date legally is when build commenced (ie chassis welded up). Maybe it was the build date not the registered date and the chassis dates were declared as pre August 1992??
FFG
It may sound 'dodgy' but in fairness the changes would have much more impact on low volume producers, so probably just common sense for once on both sides of the law.
On the other hand merging in cat cars to meet the new laws may mean they didn't just use up all the 'pre-cat' chassis first ~ its not like you can just throw a on/off switch ~ so there may be quite late cars with pre-cat chassis? Still not 'dodgy' just managing a changing situation in production IMHO, it's not like they could afford to chuck a pile of old chassis on the tip...
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