hi guys just got the zed out of storage ready for the summer and the idle is to high whilst warm (ticking over just over 1000 rpm) this fault is intermittent, but i have traced it to the the back end of the plenum, where the loom feeds in for the injectors/coil packs etc someone has been into the loom there before looking at the loose black tape around it, but when i move the loom the tickover speed drops to where it should be, then raises when i release it so guessing broken wire in there somewhere, which units on the plenum control the tickover speed?

The IACV (Idle Air Control Valve). I think the connector is common to other plugs in the bay so should be easy to source and replace.

Also a great result that you have isolated the source of the fault [emoji106]

Disconnecting the Idle valve should drop the base idle on a warm engine to like 650. If it's sitting higher than this then you need to investigate other things too, such as the base idle, TPS etc. I have mine sat at 1k rpm at idle because it improves drivability, my neutral switch has failed.

cool that'll keep me busy i think i replaced iacv plug a couple of years ago but worth a check

well just a quick update i've now resolved this issue, turns out when i got into it a bit deeper, the problem wasn't exactly broken wires, the connector on the air regulator had gone brittle and popped off, but would not stay on once put back on, then when i removed the rubber cap i found the earth wire broken off and the insulation around the the positive wire quit badly split, so luckily i had new connectors here which i bought a couple of years ago (obviously i never replaced it as i thought) so fitted a new connector, i then checked the iacv and ficd connectors, the iacv has a yellow connector on and it tight so may have been replaced or still has it's clip intact, the ficd though had also popped off, so i replaced that one as well and now i have correct tickover

Well done.