mr2 hunting

[simpson_eh]

HI all

my mr2 rev 3 turbo runs fine in the daytime but when i turn the lights on the engine revs hunt between 1400 and 600 and ideas why this would be

regards

tony

[LukeSi]

Is it scared of the dark?

[b4nk51e]

Is it scared of the dark?

[simpson_eh]

lol i still need the right answer lol

[Scruff]

Sounds like an earthing issue. Can't be of any help past that though.

[Willenium]

Poor charging maybe? Perhaps during the day when the lights aren't being used it's managing but once some additional drain is added to the mix the alternator can't keep up.

[b4nk51e]

As above try switching on heated rear screen maybe use electric windows see if the revs move about could point to load on the alternator

[simpson_eh]

tried the heated rear screen/ac/windows only happens when i put headlights on its an apexi ecu if that helps or makes a difference

[KarlBristol]

Maybe a short circuit/bodged wiring to do with the headlights

[KarlBristol]

Also, is this a relatively new development or have the revs been playing up for some time?

[toxo]

The Apexi has a weird way of dealing with high electrical load, you have to put it into a config mode that I can't remember the name of and then turn EVERYTHING on and it learns that that is the draw for 'high'. It doesn't have an ELS pin like the stock ECU does. Maybe you just need to redo that? Unfortunately that is the sum total of everything I know about PFCs, I don't even know how to get it into that config mode, just that it exists.

I am also assuming that by 'apexi ecu' you mean a power FC and not a piggyback.

Edit: http://www.paulr33.com/powerfc-faq/powerfc-faq.htm#33

[simpson_eh]

headlights havent been touched and yes its a power fc not a piggy back

def something electrical as when i turn the ac on the revs pick up as normal just doesnt like the lights