the car has been running great for months after a long slumber. now a new issue has arose, when shifting thr car into reverse the motor will quickly shut off, runs good in all foward gears. I do hear a whistle when going foward. i am assuming it is a vaccumm issue? what do you guys think.

 

definately a vacuum leak. had the same problem with my old 81 bonneville. in fact id wager its the vacuum hose running to the transmission. others might disagree and say its probably the vacuum hose to the PCM