Air in my fuel lines?!?!

[tiredtiretodd]

I noticed bubbles inside my fuel filter after shutting off the engine today. Not just a few bubbles, it kept bubbling for about 3 to 5 minutes. This is after driving it for the first time in about a year and it sat for several years before that. The back story is that this square was bought with me knowing that it would need a lot of work to get it drivable! Well Today was it’s maiden voyage and it shuddered and backfired the whole time. It drove fine the last time it was driven a few months to a year ago.

 

[1987 GMC Jimmy]

I'd make sure the evap system is working properly (good canister filter, gas cap, and vacuum lines). I'd also check your rubber lines for cracks because they can pull air in that way.

 

[74 Shortbed]

If it sat that long with that skunk piss in it that's the reason for all the backfiring, stuff is bad and probably stinks nasty too, all the rubber is probably all eaten up by now and needs to be replaced, that ethanol **** destroys everything. Whole system needs to be drained and checked from one end to the other..

 

[tiredtiretodd]

Another thing is that it used to have dual tanks and the driver side tank was removed and the lines were plugged off. Guess I’ll be tracing the fuel lines and possibly replacing them. As for a evap tank, I’ve never seen one and don’t think mine has one. I looked at the filler neck and hose coming off of it and there was a little bit of fuel on the outside of them so I’ll be replacing those hoses and clamps.

 

[Honky Kong jr]

Another thing is that it used to have dual tanks and the driver side tank was removed and the lines were plugged off. Guess I’ll be tracing the fuel lines and possibly replacing them. As for a evap tank, I’ve never seen one and don’t think mine has one. I looked at the filler neck and hose coming off of it and there was a little bit of fuel on the outside of them so I’ll be replacing those hoses and clamps.

It should of had a charcoal canister on the driver side mounted to the radiator support drive an towards the frame.

 

[tiredtiretodd]

It should of had a charcoal canister on the driver side mounted to the radiator support drive an towards the frame.

If it did it’s long gone now. Wondering what year they started that?

 

[Honky Kong jr]

If it did it’s long gone now. Wondering what year they started that?

Probably 74ish that’s when they started the emissions craze lol

 

[1987 GMC Jimmy]

Well, as long as it's venting properly, that's all that matters. But yeah, the stuff about sitting couldn't be truer. Your sending units are probably junk because I've seen them rust sitting like that, and I don't imagine your rubber lines look so pretty. A carb doesn't like to sit that long, either, and mix in today's gasoline... I'd just go through the whole fuel system from the strainer socks to the carburetor if it were me.