1987 grand am remove oil cap engine dies

Sounds like a PVC valve is stuck open. Go to GAOwnersClub.com to find out for sure.

if i un hook mass air flow it wont die

Ok if you take the oil cap off causes the engine to die, it sounds like it's allowing a massive vacuum leak, so what i am getting at, tenspeed is right on. PCV or Positive Crankcase Ventilation, is vacuum straight from intake manifold sucking air out of crankcase in to intake burning it through the engine. The PCV valve should close, it's purpose is to not allow backflow, or air pumped IN to crankcase. The mass air flow sensor simply measures the air flow so the ECU will know how lean/rich to run the engine, it will not necessarily cause the engine to die. When you take the cap off, and there is a vacuum in the crankcase, and the PCV valve does not close, the engine will die. A PCV valve is cheap and easy to replace

What engine is in your Grand AM? 2.0 L SOHC? 87 was a weird year for the Grand AM as they changed engines took the engine out of the Sunbird GT and made it an option in mid 87. Knowing what engine can explain a lot as GM was messing with their power plants a lot and had a lot of very strange problems with some of them, nothing every devastating just odd, like what your talking about, the guys are right though in what their telling you. This was the big year and start of GM developing one of the best engines ever made the 3.8L L67 Your car did have the option of different engines listed below. 2.5L Tech IV or the 3.0L Buick V6 is this the SE? I think you would have mentioned if it was the turbo charged, wouldn't you? If it's got a turbo well that is another story.