I drive a 1960's Triumph Herald 13/60. My rev tacho always sat at 1000rpm when idle, but now it sits at 1500. Same when i drive, my revs are always higher, costing me more fuel and making the car louder in general. Any help here? I'm assuming its maybe a vacuum leak, but i've tried spraying starter fluid around the pipes and found nothing.

Alongside this, my car also struggles to start, and it gets worse every day, taking longer to kick in. I know it's not the starting motor as it turns over perfectly, but it struggles more and more to catch on and kick the engine in to running. Not sure if this is related but started happening around the same time.

Finally, i also noticed the temp gauge to be cranking up faster, and feeling the engine, it does appear to get hotter quicker than it did last week. Again not sure if this is all related or not. I checked the throttle and choke, they're all good, nothing getting stuck or tugged.

This all started happening randomly a few days ago...any ideas or similar situations?