my 320i 1500rpm running sh1t. (small update)

[ah]

My 1990 320i cab has the most annoying fault I've ever known,can someone help.When driving the car around 1k-1.5k it kangaroos,anything after those revs it flys.Also at standstill when you blip the throttle the engine fails to pick IE it dies for a second.On more than one occasion it will not start for about 2 minutes or so,it also seems to be slightly misfiring all the time,but better the faster you go,and it much worst when the car is cold,The things that have been changed and checked so fare are-new fuel filter,new main rubber hose on inlet manifold,all 6 new plugs,new rotor arm +distributor cap,second hand air flow meter+crankcase sensor,new TPC,new temperature Sensor,new HT leads,valve clearance adjusted,checked the multi plug under the inlet manifold seems to be OK.Ive also checked every where for air leaks but cant seem to find any, I had a couple of ideas today and I would like the zones opinion whether you think I may be up the right tree,could it be a knackered fuel injector,or a fuel pump relay, PLEASE PLEASE CAN SOMEONE HELP! as Ive had to live with this fault for the last year months,plus 6 different mechanics to try an find what is wrong but with no success. I found lately that the idle goes up to 1000rpm+ for no apparent reason and then the car runs slightly better.Also it has never run up to temp IE 3/4 but again lately it occasionally runs up to proper temp,maybe these to are connected

[Speedtouch]

Which ECU do you have? The later 0 261 200 381 type were reknowned for diodes failing in the idle control circuit.

A chip may also help, to remove the flat spots.

[Brianmoooore]

The one thing you've missed from your list in refurbed injectors, which should have been right near the top of the list, just after checking for air leaks.