how very odd - good luck withthe hunt - seems strange though that hte issue can't be traced!

One question - do you use supermarket fuel all the time?

My folks had exactly the same issue with their car and it was down to the fuel they used - as soon as they bunged a few tanks of super in it - and then switched to garage fuel the misfire/stalling went away.....

the fuel choice may be a cheap way to problem solve?

I'll be honest, whilst forum advice can be brilliant, at times like this it can be very misleading aswell. From what you've said and I've read in your previous posts, my advice is stop changing parts that other folk have said caused them problems. Take it to a garage that has an interest in Mg / rover. As I read "rovers are like that with code readers" from your other post, that's a load of bollocks. Every car is like that if you have no clue to what you are doing. If you were closer idve liked a look. It sounds like something simple but without seeing it or knowing what anyone else has done or "checked" before, it's virtually impossible to guide you. It'd be a stab in the dark.

For the record, common problems listed on here such as ;

Idle control valve issues - I've never had one on any k series.
Poor pump fuel - never one. Heard Jap cars have the odd issue.
Lambda sensors - never had one fail.
Throttle bodies leaking - never.
Blocked injector - never.
Ecu failure or malfunction - never.

Now in no way shape or form am I saying that any of the above won't happen or have issues, but when I read this forum it reads like these happen constantly. In my experience of 12 years and numerous rovers in all models, I've never seen it.

One thing to check that I have touched on before is to check the wiring loom behind the inlet. Where it meets the metal pipe causes chaffing and shorts out the wires. Effecting usually the map sensor, injectors and idle control valve. You can almost bet that it won't have been checked unless by someone who knows these cars.

Hopefully that doesn't sound too high and mighty, but I hate to think a good car would go to waste due to bad advice and shoddy diagnostic skills.

Really appreciate the advice mate.
The garage is at the bottom of my road so I'll pop down tomorrow.
I do trust the garage though, the chap who owns it has 3 classic (MGA, B and Magnette) and a ZR.
From what you describe that could well be the issue. Will report back ASAP.
Would love to have it back, but it's so frustrating!

Car is being transported to a specialist in Cambridge tomorrow to hopefully rectify the problem. Just hope it's fixable!

Finally heard back from the garage. The part that the bottom end of the cambelt sits on has chewed itself inside, damaging the crankshaft in the process. The timing however was spot on.
Changing the part later today to see if that rectifies it.

Hopefully a fix, that's exactly what happened to the guy on RT, it seems weird not to have a Woodruff key to locate the crank sprocket.

Interesting find, quite how it did that is another matter. Fingers crossed it gets sorted and is fit and well.

Common fault mate. I thought the other garage had checked that????????

It shouldn`t effect the crank though. I`ve had them 4 teeth out and only superficial damage.

To be fair they were just looking at it when they had time, but hope this does the trick. Wish I lived nearer Scotland as all the help is up there lol.
The damage does look superficial on the crankshaft though so not too worried.
Also the inlet manifold gasket needs changing and he said about 2-3 hours labour, is that right?