Hey All, I'm a new (to me) LR owner and new to the forums. Just wanted to add my experience with Robert's GEMS app to the thread in case anyone wanted an idea of how it's working in 2022.
I just got a '96 Discovery I GEMS 4.0 V8 from my father-in-law, and the first issue I noticed was a high idle upon startup (approx. 2k-2500rpm). The idle was this high only in Park or Neutral, but upon shifting to Drive or Reverse it immediately went down to 700-800 and was very reliably changing up and down when I shifted between P and D. I suspected an idle air control valve issue, so I took it out, tried to clean it, but ultimately replaced it with
THIS ONE (it's a Mopar part for a Jeep Cherokee, but it fit just fine, although I had to remove the included o-ring and cut a new gasket for it). I also poked around and buttoned up a few vacuum leaks that I found (fuel pressure reg to plenum and loose fitting between MAF and air box), but the high idle in P and N still persisted. I found this thread and ultimately tried Robert's GEMS app with the cheapo Micro Mechanic OBD dongle I already had, but I couldn't get it to connect to the rover's ecu. After some chatting with Robert, I tried ordering a new, compatible OBD reader from Amazon (
Linked Here) which was only 14 bucks. I plugged it in, fired up the app on my phone, and it connected right away. I did an adaptive values reset, and like magic the rover cranked right up and idled at 690-700 rpm, steadily. I just did this today, so time will tell if the idle creeps up and I have a more serious issue that needs addressing.
I'm using a Google Pixel 4a with the newest Android 12, so there are no apparent compatibility problems with the new Android update.
Big thanks to Robert for all the time and know-how he put into the app, and saving a lot of us an expensive trip to the shop for a few bits of code.
