Ok so bit of an odd issue with my 93 Mk1 1.8..
It's high mileage, 260k Kms
When i first bought it, it had a habbit of bogging out sometimes, running rough and just generally poor.
Swapped the CAS to a known good one
New Coil pack
MAF to a known good one
Leads and plugs
Seemed to be fine for the past 4 months or so after that.
Other day 27 degrees, nice hot day, i took it for a long run, about an hour in it stuttered and came to a stop, turned over but wouldnt start. Few minutes later it starts and its fine, for maybe 30s down the road and same again, longer i left it longer i could drive it. Fairly sure its heat related.
No codes thrown up, because i was over an hour from home i left it and got a lift home, went back and got it the next day and it made it home an hour with no issue, i left it running on the drive for a bit and didnt cut out.. not sure.
Its intermittent and only ever seems to do it when hot and its been running for a while, its not overheating and nothing out of the ordinary, no loss of power etc.