Ok I need some serious help 81 Sierra starting problems

[81granderod]

My 81 Sierra had problems starting and I saw no choke was hooked up so I put on a manual choke. Had no problems! Until I went to fill up my tank before work and it would not start! This isn't the first time it's happened when I put gas in it.. So I'm thinking it has to be a vacuum lock in the tank or a spillover or something in the gas tank an 81 might have.. But I have no idea. Does anyone have an idea what might be goin on? Thanks

 

[dirtclod]

So, did you check to see if the engine was getting any fuel? Did you check for spark? I can imagine your scenario. Stuck in a line at the gas station and fearing you'll be late to work. Been there.

 

[2001 GMC Sierra]

If you overfilled the gas tank and the Evaporative system pulled raw fuel into the carburetor system, it might have flooded the engine. Next time try leaving the gas cap off after you get gas... Ron

 

[81granderod]

i tried leaving the gas cap off, because i heard that there might be a vapor lock or something, which i assume might be the evaporative system u mentioned. it wouldnt start so i caught i ride to work..came back 3 days later and it fired right up..no idea why it would do that haha. drove my truck to subway today then it wouldnt start. the carb is definately getting fuel, just doesnt want to spark and it keeps turning over and over until it dies.....maybe something electrical? though idk what would be electrical on an 81.