MK2 k-jet engine prob- HELP!!

[strega]

Hi guys,
My k-jet runs sweetly when driving, very strong and quick etc, but today it has decided it wants to cut out completly when idling, it DOESNT do it when I dont have anything drawing from it, i.e. lights heater fan etc, but as soon as i put the lights on the engine  hunts then dies totally, any ideas because its worrying the heck outa me 

[psenior1]

I had a similar problem on mine where when hot  and you switch on the lights and fan etc you can hear the tone of the fuel pump change and it will start hunting.  I replaced the alternator which improved it alot, though not completely.  I've also cleaned up the earth from the battery to the body and gearbox, next on the list is the battery, though it does seem to hold it's charge OK...

If you've got a multi meter check the voltage across the battery with the engine sat at 2500 -3000 rpm with everything switched on, think it should be 13.5-14.5v.....

[Gambit]

does sound like the alternator.

if the alternator aint fully charging then the battery light on the dash should glow ever so slightly. very hard to see in daylight.

once it stops charging altogether then the light will come on full!

u dont run any large sound systems or anything like that?

[rubjonny]

Take the plug off the fuel pump & clean up the contacts then reconnect.  Next replace the fuel pump relay

[strega]

Hi guys, many thanks for the helpfull explanations, will have a go at them and see which it is, Im not running any sound system at all in it so cant be that, well I'll have a look and see, thanks guys