4000csq running problems

[David Jankowski]

have a strange problem.  have an 86 4000csq with 130k on it.  car has a
small misfire that i have not been able to find.  it is intermittent just in
the fact that it went away twice after setting the car up.  i just replaced
the cap, rotor, plugs, wires, o2 sensor, injectors, and load control relay.
checked fuel head, isv, spark, and connections.  noyhing is out of the
ordinary.  the two times that it cleared up have almost no similarities
other than the car has been run inside for about half an hour both times. 
if anybody has any ideas it would be very helpful.         david jankowski