16v idle with lights turned on - SOLVED

[tony_ack]

My valver idles fine when warm and cold during the day, but as soon as I turn the lights on, the idle goes up to about 1250-1500 rpm, and hunts like crazy when returning to idle after being revved/driven.

When I turn the lights off again, it returns to normal.

Any ideas to make my car less afraid of the dark?

[walchy01]

Hi There

Had this before on a previous valver, stopped using it in the dark

Sorry but never resolved it......

Some expert on here will though, any joy on your garage???

[tony_ack]

Nope, no luck on finding a garage or workshop - I've been looking on and off for about a year, so I'm not expecting to find anything any time soon

[tony_ack]

No-one got any ideas??

[Wayne]

Could be a idle control valve problem that only shows with the extra load.

[jezza16v]

Try re-tuning it from scratch. The idle speed has to be set with the isv disconnected and when the cooling fan and lights are on iirc, been a while now since I've done this. Mind you when you put the lights on the revs would normally drop a bit. Could be that your ISV or its controller is dodgy and over compensating when you put the lights on???

[rubjonny]

no you set the idle with the red/black wire disconnected near the coil, with lights off.  worth resetting the idle as above though, there is a guide on it in the maintenance section.

If that doesn't help then I'd agree it sounds like isv or controller may be the problem, check the red/green wire to the single pin black sensor on the side of the head is connected ok, and check the condition of the brown and brown/white wires to the side of the head.

[jezza16v]

Ah, yes, everything turned off not on, senile dementia setting in I'm afraid..........doh! But have to wait til fan comes on to show its well hot and then set idle while the fan is off, I seem to recall disconnecting breather pipes and plugging holes as well, or was that for CO..................I give up!

[rubjonny]

yah disconnect the breather from airbox, but dont plug it just point it somewhere it wont allow fumes to be sucked into the airbox

[tony_ack]

Sorry to resurrect this, just thought I'd post my progress so far.

Changed the ISV for the one I had replaced it with, and no change.
The garage reset the CO/Idle after I fixed some air leaks on the inlet and exhaust. No change (though CO needs setting again as it's running lean now)
All wiring on the side of the head seems okay

I notice that the idle improves slightly when I turn the dash lights down, and picks up when I turn them up again. There is a mass of dodgy wiring behind the dash (retrofitted electric windows with 'custom' loom  ) so I would bet on an issue with the ISV controller, or the wiring (maybe it's sharing an earth with the dash lights or something else on that circuit?)