Hi all, well got a bit of a problem with the Supe. Basically when I start the car it will idle at around 450-500rpm and it sounds as if the car is going to cut out, there is also a rattle ive been having under the car for around 2 weeks now but thinking its the heat shield, will that be also a possible cause of the low revs that have suddenly appeared? it was always at 700rpm idle but now its down at 450 and as I set off in traffic it will sometimes judder as if its going to stall any ideas? tried search but cant find anything for an auto on this. O and it goes up when I put the AC on but dont want to keep putting that on everytime i hit traffic.
EDIT: Also the positive on the battery seems to have a slight build up of battery acid (when it goes white) but cleaned that off and seems fine now but still the revs are low