Revs are idling lower than usual on start up and car is stalling when I brake with the clutch down. Starts up fine and runs fine every other time. Isn’t overheating. Just had a new head gasket fitted. Don’t know what is causing it to cut out?
My guess would be some sort of a vacuum leak. Most likely an oversight when doing the work replacing the head gasket. This would be what I would look for first assuming of course the check engine light is not illuminated.