Vapor lock or fuel pressure issue?

[79malibu350]

Hi all, long time no see but i am back! :lol: so the old gal developed a bit of an issue on me late last year, namely when i drive it work, about 25 miles, it always wants to die as im pulling into the lot, or whenever else it drops to an idle and i dont keep the RPMs up a little. It sometimes will do it on shorter drives too. It can be pretty hard if not impossible to re-fire after an episode, at least for an hour or so, then its fine again. Usually, if i floor the throttle it will start, but it doesnt want to idle. I admittedly am a bodyman, and by no means a mechanic so im perplexed. Could the fuel be getting to hot? should i change the lines, try a different filter, maybe a spacer? Ive also noticed a very high build up of pressure in the tank, to the point it makes the cap dance if i loosen it even after a short drive. So thats got me wondering if it is getting to much pressure to the float and flooding. Im wondering if i need a pressure regulator, or a carb spacer, or both. Thoughts opinions and request for any more info are appreciated!

 

[Fox80]

Pressure in the tank is most likely your problem, find the vent line where it runs into your charcoal canister, remove it from the canister and tie it up and drive it to see if it will build the pressure again. If it does you have a blockage in the line or the sending unit, under the car you have the two or three rubber connection from the tank to the hard lines, find the vent and see if you can blow through it. Start with that stuff good luck

 

[79malibu350]

well, tried a couple of things. replaced the crusty old gas cap and wrapped the line from the pump to the carb in foil, with a couple corks banded to it for good measure. New vented cap seems to help the pressure build up, but i guess i wont know for sure until it gets alot warmer here :?