speed reads wrong since my c20let conversion from the computer only - new speedo unit sorted the dial readings(20/160 instead of 20/140) - is the comp one driven from another source, ie maybe abs sensor, if yes will i be able to purchase a cal turb sensor(if there is one) to rectify this little niggle
comp was miles out when i had 140 dash upon turbo conversion,- 160 dash cured the speedo but not the computer - only thing off my dial is the cable to the gearbox, there is an electronic devive on the speedo but this is the right dial for the engine and is not reading on comp right
I believe richard bells is of the new version where it was factory fitted with a 160mph speedo driven from an ABS sensor.
The fuel computer is also driven from the ABS sensor.
So when Richard fitted the turbo engine there was no need to change the speedo/fc as it still read correctly. (nothing to do with engine & gearbox you see)
However the early type has a mechanical speedo between the gearbox and speedo.
There is a sensor in the back of the speedo which drives the fc.
If the fc is incorrectly reading it is adjusted by changing the program code within the fuel computer and not the sensor in the speedo.
Sadly I don't know what the code should be reprogrammed too and the job can be expensive.
Also the FC will read wrong because it has C20XE fuel cons values and not C20LET values.
A program code from a t200s would be a useful start. This should be able to be found by holding down both buttons on the wiper switch and the code should be displayed. (or get the colour code number from the slam panel). You will need the number from a t200s with the same sort of speedo as yours though (ie mechanical or electric)
However I fear it's too much hassel and not an easy fix.
I have an LET in my Mk3 with F20 gearbox and a digidash...
speedometer readings are OK ... fuelcomputer-readings AREN'T.
Guess that's the same problem ???
Haven't found out what to do about it , though...
so andy, is it possible my old 140 dash could have been off an abs sensor not off a cable, hence the dial read incorrect upon fitting of the let engine, when the car went back to have the speedo sorted, is it possible they just used a cable driven 160 dash and fitted a cable to the gearbox, i cant remember if the old 140 was cable or electronic as i never had it returned to me, my rev counter also used to be 7000rpm and that was also changed for a 8000 version, along with different temp and fuel display dials - think ive learnt me lesson in the art of car modifying lol, never do it again