Have you tryed unpluging the two water temperture sensers on the bottem of the inlet manifold ? As it could be one of these braking down which makes the engine think that the engines temperture is At
-41' hence your over fueling/no spark, most BMW e30 89-91 2.5-2.0L run a simlar Bosch mechanical injetion contactless distributer engine management and have the same sensers Brown and Yellow at the front of the cylinderhead which causes a miss fire on the BMW but will tickover failtlesslymiss at low revs but rev freely between mid rev range and rev limiter ,on the Rs it ticks over perfect but will miss and overboost at low Rev's unplug the brown wile engine is runnig see if this makes a diffrance for the Yellow sencer ive found that you'l need to change this becouse this needs an earth unpluging this causes engine to stall unless there is a short in your lom which can cause smiler problems which seem more complex then they are , But also have found rocker cover lose it causes a vacume leak ? there are so many posabilatys for air leaks : Round the throtall body : Boost hoses and very rarely rust or splits round the servo all of these are easy to diagnos with a tin of carbretter cleaner gentley sprayed round any of the above areaswhich if there is a vacume leak the carbretter cleaner causes engine speed to incress . Streched turbo studs can cause same problems over time .
Ben Stanley BennyboyRS hotmail.com
December 2009