tickover problem
 

my 1993 torslanda has developed an odd problem
starts fine.ticks over when cold fine but when warm sometimes the revs wont drop below 1600
doesnt affect the running.no stuttering.picks up fine and then after four or 5 miles tickover drops to normal at about 900
any suggestions?

I get that periodically. It's always been the idle air valve - alloy can underneath the inlet manifold - sticking.

It's easy to remove and clean -squirt WD40 into it and use a small brush to wipe the accumulated dirt clear of the rotating vane. You can rotate that through the end hole with something soft, like the wooden end of the brush.
Rotate the shutter open and squirt WD40 generously to wash it out, checking that it snaps back nearly closed when released.

Don't be tempted into fiddling with the idle speed screw - that's preset, idling is controlled by the IAV.

thanks clifford
will have a go this weekend

did as clifford suggested. amazing amount of crud in there
cars running beter thanever
thank you clifford