tomoyb

iTrader: (3)

my car used to idle fine.

ive had this hassle with previous cosworths and usually the iscv
but not this time ive got 3 in total and all do the same

had the car on rolling road and ever since it has done this hunting between 6-12rpm

car was running lean so fuel pressure was adjusted to compensate,at the same time I removed the dumpvalve and plugged the vac hose from inlet(im confident its sealed)

car is ok when started from cold its only when it warms up,and if I unplug the iscv it will idle steady but low as you would expect

anyone have thoughts on this?

l8 4x4 po08,msd setup

gingerturbo

iTrader: (2)

You may find it is still an iscv problem but with the loom/plug have you checked the wiring coming from the iscv

richard youll

In plug the iscv and see what it ticks over at, when you unplug the iscv there should be no rpm change at all what so ever , if the revs change the base idle screw needs adjusting till you can unplug the iscv and there is no rpm change that's the most common fault

tomoyb

iTrader: (3)

Theres nothing wrong with wiring.
I was going to mess with base idle
if iscv unplugged it ticks over evenly but obviously low like 600rpm
but can adjusting fuel pressure cause this?
I didint think so

as said it was spot on for years up until this point.then the hunting started

richard youll

Quite possibly , I've never had a faulty iscv ever and customers that have replaced there own faulty ones allways end up needing base idle setting to cure the real fault