Battery Isolation switch ?

[TeGriffic]

I’ve just got a 4.3 1992 Griff and in the passenger footwell is a red plastic key with a small lug on it. It is, I am told, a battery isolation switch. Now, the arrangement looks, by way of the rubber cover, as though the key is not designed to be left there and thus, I thought I’d remove it. I think I have now momentarily isolated the battery. Interestingly, the car now idles incorrectly (see my post “Revs won’t drop”).

Presumably, by doing this, I have reset all sorts of things ?
Would that be a correct assumption ?

[Guillotine]

sounds reasonable.

disconnecting the ecu will return it to factory settings. it will now "learn" about your car over the next few miles.

if the car wont rest at low revs, its usually down to the valve at the back of the plenum which along with the ecu/injection modifies the tick over to acount for excessive loads like fans on, a/c on etc. and /or general engine conditions.

if you clean it (the stepper valve) run the rag aroundthe hole as well to ensure a good seal.

cheers