Ok , i have spent nearly 50 hrs trying to solve this one.

At 1,3 bar at 5800rpm it starts braking down until 6200 rpm there is a complete brake down almost like a rev limiter.
At 1 bar it is fairly clean.
I have check and replaced :
Plug leads
Plugs - now i have KHS Iridium i45 with 0,6 mm gap
MSD twin tower coils x 2
MSD Dis 2 Ignition amplifier

Set Crank angle sensor to 0,8 mm ( spec 0,6 to 1mm)
Set Distribitor to 0.15 mm magnetic pickup
Checked distibutor and coils on a bench test.

Set up distibutor as follows :
TDC on the first pickup tooth after the cut in the crank pulley. Turn distributor to line up with a slight cut mark on the round base . Near perfect alignment.

Is there any knock sensor on these cars ?
Can a air or water temp sensor cause this ?

Any help or ideas please , please ,please

 

have you checked your fuel pressure?? i had a similar problem with mine! there was a miss fire at 5500rpm but if i kept my foot in it went again as the fuel pressure had a moments chance to get back up again!!!! when i put it on the rollers with there c02 machine it was blindingly obvious that there wasnt enough fuel so i uprated the pump then back on the rollers and hey presto it worked fine

 

got 2 fuel pumps and a pressure meter -no problems there!!
thanks anyway!!

 

i had a similar fault

voltage drop

alternator/battery good

 

Its a new battery but as you say i must test that will do on a dyno !!

good suggestion !!!