I had the exact same problem on my car.
If it still goes out when the crankcase vent is open and you rev-up, it's most
likely worn rings, worn vales or more...
I did everything I could to fix mine, and nothing worked...
Until I rebuild the engine, since then I have no problems, and I pass
emission, even with a Webber and all the emission stuff removed...
Have a look at: http://hpmad.homeip.net/eng/mgrebuild.html and
The rebuild included:
- fix the head cracked), valve and harden seat job, clean block, overbore
cylinders, grind and balance all rotating stuff (crank, rods, poulies,
flywheel), change flywheel gear, polish all bearings and moving stuff and cost
The parts (including gearbox rebuild): high compression pistons, rings, new
perf camshaft, all seals, all valve train, pushrods, tappets, timing stuff,
bearings, bolts and nuts, engine holds, oil pump cost me in the $1100 range.
Plus I got to buy new toys... Heu, tools...
It took me around 2 months (mainly waiting for parts and having to fight with
the cold as I did it in winter).
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