1986 jimmy wont start help appreciated...

[Schwedy925]

Hello. So im having some trouble with my 1986 4x4 jimmy. When i first got the truck not too long ago it would take a little while to start if it hadnt been running for a while (ie usually in the morning i would turn the key and wait for it to turn over while giving some gas until it started usually about 20-30 seconds or so). Last night however when leaving the store i started my truck and it seemed kind of boggy and then when i put it in reverse and gave it some gas it just died. I went to start it again and it just keeps acting like it wants to turn over but the engine just wont start. I tried jumping it and the man at AAA said it sounded like i was out of gas by the noise the engine was making when trying to start it (i already put a couple gallons in while it wasnt running so i know its not that). I let it sit overnight infront of my house and when i go to fire it up this morning it just does the same thing. I did some research and i THINK i may need to replace my fuel pump or somthing along those lines. The people on this board seem to know what they are talking about so i figured i would bring my problem here and see what advice you guys might be able to shoot my way. Any help is greatly appreciated. Thanks.