88 E32 dies after warm

So I was having some issues with the battery always dying on my car but I found out it was the alternator and had that replaced, now it seems I am having a whole new issue, my car will fire up just fine when it is cold but after it has a chance to warm up when I put it in gear it and drive it, it will die and then will not fire up again until it has a chance to sit for a couple hours. Any ideas? I am at a loss.

Thanks,
Iain

An help at all would be awesome, I am a little over my head here

I also have an 88 e32. An easy and free try would be to unhook your battery for a while and then hook up again. It has fixed a few problems for me. Also curious if once it has cooled down and re-started does it run okay?

No, once it cools down the same problem happens after a few minutes of driving. It will stall out and die and then can't be re-started until cool

coolant temp sensor