5kcstq idle problems

[mark Rutherford]

Car: 86 5kcstq.

Symtoms: Car has been very hard when it is warm for about a week.  Over the
weekend I replaced a few vacume hoses, this helped the hard start problem.
Car started Ok(not great but OK) on Sunday and Monday.  Today the hard start
comes back with a new problem.  The idle is surging between 1100 and 1600
RPMS.  I looked at the duty cycle of the frequancy valve to check the
mixture and noticed that mixture would vary from 35 to 65 in a constant
movement(not the normal 5 or so degree variation that is normal) and then
shoot down to 35 and start the process over again.  The movement is in phase
with the idle and takes about 2 sec.

Tried: Unplugging the idle stabilizer has no effect. unplugging the O2
sensor no effect.  Looked for vacume leaks none found, does not gurentee
that there are none.

Ideas

Thanks
5kcstq at sisna.com