1988 Fuel Pressure, Causing Flooding?

[BMH9008]

I own a 1988 Chevy Comaro with a 305 TBI. Sometimes, when the car is warm and you go to start it, it will flood over and not start. I believe my problem is excessive fuel pressure build up in the tank. If I release the fuel cap you can hear the air rush out and the tank even collapse from the pressure. Could this be forcing to much gas into the engine, why is the pressure building up, and is the car suppose to release the pressure itself?
P.S. When I removed the fuse to shut off the fuel pump, the car started and ran for a long time, poorly, but ran.

[wrightz28]

Run your ecm for codes, I'd almost bet you'll get something in regards to the EVAP system.

[89IROC&RS]

my sentiments exactly, sounds like a vent valve is not opening or closing, the "hisss" sound when you open the cap is normal when the tank is almost empty, but it should not be so bad that the tank itself actually changes shape due to the pressure change. it does sound like the pressure in the tank is so high that its pushing fuel up the line past the fuel pump even when its not running. there is definatly a problem with your evap system somewhere. i suggest you stop driving it on the road, if your fuel tank is deforming that much under pressure its not safe to have on the road.