The engine is a 3.8L Supercharged no mods. I just recently had the Crank shaft pulley wheel and the harmonic balancer replaced with new ones and the car has been running great for three days although today I noticed that the rpms kept dropping well it was idleing then I went to start it again today and twice in a row when I put it into reverse the rpms dropped to 0 and the engine stalled out this is an automatic car I have heard different things I don't know if its the mechanics fault that installed that part or it has something to do with the air idleing control motor or if its anything worse.
Any help would be great
Thanks
Any help would be great
Thanks