Have just got Rovergauge working on my 99 Disco 3.9, I bought cable from ebay, WORKED FIRST TIME
. what a brilliant piece of software! Anyhow, I need a little help interpreting the results and faults.
First off my AFM is reading 27% on the direct scale, this seems low considering I have seen a 32% figure quoted for a 3.5, I am using the 5AM meter. Also when measuring between the blue/green and black/red wires at the AFM with a volt meter (at idle), I also get a low reading of 1.4v, reading up it should be somewhere between 1.6 and 1.75, the reading between the same wires with engine not running was 0.3345, I am unsure how accurate the voltmeter is though! Also the reading between the other wires was 1.83v so seems OK on CO front?
Anyhow its an Old meter (date stamped 94) that I got from the scrappy a couple years ago to replace a rubbish aftermarket one fitted.
The other issue is that the engine always races to 2000rpm when started, dropping back after 5 seconds of so, I can see on rovergauge that idling normally when warm the car stepper is only open between 0 and 3% to keep the target idle. Base idle is set at 525rpm with hose clamped. I took the stepper out to clean it and unfortunately broke it trying to refit, so have another on order
However what would you interpret from these readings ? I was expecting the stepper to be maybe on 20% ish with the car at normal temp. idle, just to give it some room to compensate.The lambda readings seem to be fine, short term trim tending to be on the + side about 20% ish but fluctuating between + and - under load.
Throttle pot was 4% at idle and moved smoothly.
Just for info, car has new NTK lambdas and cheapo cats, New genuine coolant temp sensor, new plugs and leads, and runs pretty well on Petrol and gas, returning reasonable economy although maybe not quite as good as it used to be.
Sorry for the long post!
Any help much appreciated - Olly
