Engine cutting off????? HELP

[aabdelhamid]

My 1990 M20 E34 520i is behaving very strangely. Two weeks ago it started cutting off when I am speeding on any gear, as soon as I reach around 5000 to 5500 RPM the engine cuts off and then picks up instantly, this could have repeated once or twice and then the RPM range would continue smoothly as is till I hit the maximum 6500 RPM and then it flickers the usual normal cut-off flicker. Occassionally when I revved the engine while standing still, it used to do the same and sometimes would back-fire.
Yesterday it cut off the same way, backfired and then BOOOOOM the rear muffler box burst and nowe I am driving a wonderfull big lawnmower (the sound is horrible and i have a lot of exhaust leaking inside the car).
Apparently the muffler box was blocked. Do you guys think it was causing the cut-off or not? Help me out please

[Ausmpower]

Ignition problem, coil?, cam sensor? could be O2 sensor, bad maf, my guess....... fuel is there hence the rear muffler doing a popcorn impression!!

Hows your fuel economy?

p.s A single backfire can srew up you afm.

[shogun]

Does that engine have a crankshaft position sensor? If so, check that for correct installation.

[Ausmpower]

Cam sensor on the M20's Shogun, Mounted in the upper timing case.

[krazy00kanadian]

im haveing the same problem with my 1990 535i. not backfireing, but the random cut-off/flickering happens. i checked the CEL codes and i got 1263 which was the purge valve. nobody seems to know aht it is/ what it does.

you may have a differant problem and thats a bummer abuot your exhost.