When I remove the oil filler my 76 l28 dies. Is this normal or do I have a problem. Car seems to run fine otherwise. As fine as a 30 year old neglected car should

 

That's correct. Your engine is sealed to give a negative air pressure condition when running.
Any opening, oil filler cap, oil dipstick...will cause an error in this ventation.

 

that is really strange. I have never heard of that and it makes no sense to me

 

Comeone Geoff,mine does it all the time, its a old POS with crappy fuel injection

 

does that only happen on fuel injected motors? My carbureted L24 doesn't do that.

 

Only a symptom on injected cars. To put it in simpler terms...the crankcase ventilation is sucking outside air into the motor when the oil cap is opened. This outside air isn't being measured or calculated by the air flow meter, thus causing a tremendously bad reading. Its just like causing a massive vacuum leak.