rebuilt engine in, but only runs in spurts

[cell]

Ok guys, so I got my inline 6 back from the machine shop and back in the truck. Problem is, I can't get it to run for more than a few seconds.

In order to get it to start to turn over, I have to pump the gas a couple of times. Then, it will run for about 5 seconds, but then dies.

I find that if I pump the gas about once or twice every few seconds, I can get it to run for about 30 seconds. However, backfiring becomes a problem, and it dies.

background: this truck ran when I got it, but I haven't rebuilt the carb, and the carb hasn't been used since I tore the engine apart, several months ago.

I have a carb rebuild kit, but I wanted to at least get it running before I tore that apart as well (I didn't want to change too many variables at once). Do I need to just go ahead and rebuild the carb?



thanks guys.