There's a sensor pick up on the bottom left of the R380 box, which can cause erratic idle if it comes loose or is misaligned somehow, I believe. I recall researching it on other Landrover forums when I had issues. My problem ended up being the throttle postion sensor. I used a cheap pattern one to start, which didn't improve things, but after fitting geuine LR part it seems to have been fine over the last 40k miles or so. You could try unplugging the TPS and running on MAF signal alone. That was how I found the problem.You won't have the performance response, but the engine should idle fine.
Good luck, Phil
