well i havent posted for ages, but have been working on the car..
since i recond my head and had it shaved 1.5mm, once its warmed up and i turn engine off it continues to run for about 10 secs (shuddering) and finally dies.

normally as far as I know this should only happen when motor is too hot. Ive fitted a new temp guage and cleaned radiator and its only running up to about 93 deg, not too hot.

I thought it might be the regular ULP not up to the higher compression and detonating, so filled wih LRP, no improvement.

i have the idle at 1000rpm, that shouldnt be too fast to be causing the problem i think.

any ideas, its driving me nuts