[911T70]

With the warmer than usual fall we’ve been having and the lack of snow in central-eastern Canada, I’ve been enjoying my 1970 911T much longer than I expected to this year, which is a real bonus! Driving it in cool temperatures, I’ve noticed that the engine performs much better. Since I’ve had it, the engine hesites and sometimes backfires, belching a black cloud of smoke at around 3000 rpm but pulls strongly elsewhere. It hesitates and backfires much less when the temperature is lower, being almost un-driveable on very hot days. I’m assuming it needs a good tune-up, which I am planning on undertaking starting my first valve adjustment over the winter.

The last tune-up was done by a ‘Porsche expert’, according to the PO, in Cedar Rapids, Iowa, which is at a different elevation than its new home, thus at a different atmospheric pressure. I was assuming this was the reason.

Does this behaviour relative to temperature hint at some other problems or does it confirm that my Zeniths need to be tuned to their new environment? Any advice would be appreciated; now that I’ve experienced how much fun this car can be, I want it to run this way all the time!