Bit late to the party here as I've been driving to get where I am (a lot closer to Super4 than normal but still a bloody long way off). I've been in exactly the same state as you are now and found that no amount of driving will get the TPS voltage to adapt down to normal. It'll appear to go part way, but all it is doing is adjusting the idle valve setting. The way it works is that the voltage from the TPS is stored in the ECU as closed throttle, when you give it a tiny bit of throttle the voltage rises and that acts like the progression jet in a carb. Idle jet supplies fuel at idle, main jet supplies fuel at open throttle and progression jet supplies it during the transition between the two. So, if the ECU sees the stored voltage, it sets the idle air valve to get the idle correct, you open the throttle a crack and the idle air valve opens to raise the revs before the airflow through the butterfly takes over and allows big gobs of air through.
So, you have two choices. Do an adaptive reset that changes the stored voltage that the ECU is expecting to see or make the voltage match the stored one. The first requires a dedicated bit of test gear which you don't have (and the unit your man has with plug in modules will be a generic tester with the modules giving the specific codes for the vehicle you are plugged into, like the £4k Snap On unit that does little more than a £30 generic tester) the second can be done with a bit of mild bodgery. Enlarge the mounting holes in the TPS so it can be turned, start the engine and let it idle at 1,000 rpm or whatever it has decided it is going to idle at, then turn the TPS clockwise a touch. That will bring the voltage down to what the ECU is expecting to see and the idle will drop to normal. Mine was like that for 3 years until I bought the Nanocom, reset it so it wasn't lopsided and poked the Reset Adaptive Values button......
Peterborough, Cambs
- '93 Range Rover Classic 4.2 LSE, sold
- '97 Range Rover 4.0SE, in Oxford Blue with a sort of grey/blue leather interior sold as two is plenty.....
- '96 4.6HSE Ascot - now sold
- '98 4.0SE in Rioja Red
'98 Ex-Greater Manchester Police motorway patrol car, Range Rover P38 4.0, in Chawton white - the everyday car
All running perfectly on LPG
- Proud to be a member of the YCHJCYA2PDTHFH club.