320i Misfire under load (between 2500 - 3200rpm)

[DJBouncin]

I have a 1989 320i 2ltr which has developed a random misfire, it occurs around 2500-3200rpm, over this and under this it seems to run ok (lacking a bit of power though) some days it can run fairly fine other days it really struggles and has a real bad loss of power, it tends to get worse once the engine has warmed up,

And recently (last 4 days) when have gone to start it in the morning it wont idle and will barely pick up revs, only way can keep it going is to put foot to the floor and hold it at high revs for a few mins and it seems to sort itself out,

It has recently has new plugs / leads /distributer / fresh oil / new air pipe between intake and air flowmeter (one with idle control valve on)

Is really bugging me now and going on holiday soon so would really like to get to the bottom of it before we go.

PLEASE CAN ANYBODY HELP?????

[Grrrmachine]

Air leak would be my best bet.

[DJBouncin]

I have checked for air leaks and cant find any at all, have visually looked and tried coating all pipes ect with a spray to see if can see anything and nothing at all

[Grrrmachine]

The best place is the rubber plug under the throttle body, which is impossible to get to with everything bolted together.