Engines turns off after prolonged running
When I drive long distances, my M800 type 2 engine turns off the moment I press the clutch pedal down to change the gear and it wouldn't turn ON. I had to leave it idle for say 20 mins and then it runs again without any problems until I press the clutch pedal down within another 5 to 10 mins. This problem did not occur when the AC was NOT ON. Starting the engine through key turn or by releasing the clutch while it is in motion did not help.
The distance was around 250 Kms non stop with no gear change in between (as it was a night drive). The moment I pressed the clutch to make a turn, the engine turned off and all lights on dashboard lit ON. I waited for 20 mins for the engine to come back to life.
I checked the temperature gauge and it was slightly lower than the middle position, the engine fan was running fine. I also opened the bonnet and did not feel too higher temperatures. No coolant leaking, engine oil issues as it has been already check at the local garage as well as MASS but they couldn't sort it out. I strongly feel that it happens only when the AC was ON. No issues with AC ON in city drives or short drives.
Any thoughts?