Back Again....
I checked the valve clearances - all good apart from Number 2 and 3 exhaust valves were both a bit tight(.010") adjusted them up so they are all fine.
I was starting to think I was having a win and convinced it was a vacuum leak/leaks somewhere........took it for a decent drive went fine, accel good, idle still a little erratic but still convincing myself vacuum leaks.....then came the highway run.
1,2,3,4, gear all smooth under light or heavy acceleration, next to no black smoke, now here comes the biggest gremlin of all.
After about a minute of highway driving about 100kph i accelerated hard up until about 130 then let it coast back to about 100 again - everything fine. I repeated this a couple of times still ok came to a bit of a hill put the foot down again to check it out...........seemed to be hesitating / flat spotting up slight hill.....went to accelerate hard again and it started PINGING ITS HEAD OFF! I eased up straight away and under light accel it was not to bad and after about another 1km of light driving I could accelerate hard again and it was ok.
But repeat that same process again same conditions, time frame, engine temp etc the same thing will happen. WHY THE PINGING!!!!!!!!really bad.
Engine temp guage read ok whole time.Returned home double check everything for the 2 billionth time. Dwell, timing, float level, vacuum advance etc etc etc. Cant fault anything.
I cant see anything carby wise that can cause this can it???????????????
HELP I'M RIPPING MY HAIR OUT!!!!!