I am hoping someone can help here, and I must apologise for my limited technical vocab, as others do for their (often very good anyway) English...

It's a late-1967, B20 122S. Yesterday it started a bit slower than normal, perhaps turning over 5-6 times. It's cold at the moment 34-38F. Started with choke full on, no problem. After 4-5 minutes I put the choke in after the temp guage creeps up towards the middle. Then after this, every time I put down the clutch in gear, or idle in neutral, the engine sounds as if it's about to cut out, so much so that I have to press the accelerator to keep it revving. When I reached somewhere to park, I experimented, just letting it idle, and noticed that it continued to almost cut out and the temp guage went right off the scale, hot end. But when I blipped the gas, and revved the engine (still in neutral) the temp went down. After blipping the gas a few time it idled nicely and continued to do so.

Did I clear something by doing this, and what should I give attention to to make sure that it doesn't try to cut out again when stopped at traffic lights etc. I should point out that even when cruising my temp guage regularly moves around from middle to the overheating point and then back to the middle, every 30 secs, but never with the accompanying symptoms described above.

Thanks very much for any advice on this.

Tom