280 idle speed
Discussion
Looked at a few earlier threads on 280 idling and seem to have similar problem.
Starts ok from cold but revs quickly drop to about 300rpm - just about stalling.
Once up to temp idles at about 500 - 600 rpm
Adjusting idle screw doesn't seem to make much difference.
Revs and drives fine when accelarator is pressed.
Aux Air Device valve is closed after only a couple of minutes which seems a bit quick. I've already changed this but hasn't made any difference. Tried disconnecting wires so valve wouldn't close and this allowed to rev fine during warm up.
What controls aux air device ? Is it just current sensitive and could it be getting too hot too quick?
What can be else can be checked or adjusted to alter idle speed ?
Any thoughts would be appreciated.
Starts ok from cold but revs quickly drop to about 300rpm - just about stalling.
Once up to temp idles at about 500 - 600 rpm
Adjusting idle screw doesn't seem to make much difference.
Revs and drives fine when accelarator is pressed.
Aux Air Device valve is closed after only a couple of minutes which seems a bit quick. I've already changed this but hasn't made any difference. Tried disconnecting wires so valve wouldn't close and this allowed to rev fine during warm up.
What controls aux air device ? Is it just current sensitive and could it be getting too hot too quick?
What can be else can be checked or adjusted to alter idle speed ?
Any thoughts would be appreciated.
From cold, the aux air device gets a 12v feed that causes a heating element to warm up and gradually cut off the air bypassing the throttle. 3-5 mins would be about right. Once the engine is warm, if you restart, the heat from the block causes the valve to be shut already so you don't get the bypass unless it's needed.
The idle mixture and idle speed adjustments tend to work together to some extent - fiddle with one and you need to fiddle with the other!
The V6 injection is very unhappy about air leaks, and you can get those from the daftest places...
Also, there's a warm-up regulator that doctors the fuel pressure in the same way that the aux air valve adjust the air bypass. Known to be problematic, hard to find as working spares and bloody expensive new. Oh, and there are two types.
Ian
The idle mixture and idle speed adjustments tend to work together to some extent - fiddle with one and you need to fiddle with the other!
The V6 injection is very unhappy about air leaks, and you can get those from the daftest places...
Also, there's a warm-up regulator that doctors the fuel pressure in the same way that the aux air valve adjust the air bypass. Known to be problematic, hard to find as working spares and bloody expensive new. Oh, and there are two types.
Ian
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