86 GMC - won't start unless gas poured in carb

[kcackler]

So this truck was starting and running just fine a couple of weeks ago. We let it sit for about 2 weeks, and I went to go start it today and it just would not start no matter what I did. So I put a little bit of gas into the carb and she fired right up and ran for a few seconds before dying. Tried starting again, and the same thing...It just won't start unless I put gas in there, and when I do, it won't stay running.

What could have happened in two weeks that could be causing this, and what do I need to do to start troubleshooting? We've GOT to move this truck in two weeks, and I'd like to be able to drive it to its new location instead of towing it. My first thoughts are maybe a clogged fuel line somewhere, or maybe the fuel pump crapped out while it was sitting?

Any tips or advice will be very helpful. I'm a bit green when it comes to carbs, so please walk me through whatever troubleshooting needs to be done. I'm willing to learn, just need some help along the way

Thank you!

[74 C-30]

i think youre right to start with the fuel line, try disconnecting it at the carb and crank it over to see if gas comes out, if no, work your way back until it does. if yes then theres another issues

[73chevyman]

check the fuel filter and your fuel pump pull the line from the carb and see if your getting fuel. if no fuel take the filter out of line and try it again if fuel the filter is clogged change it. have a friend with you when you do this have them bump the motor. damn i'm thinking like your not stock if Q'Jet the fuel filter is were your gas line hooks to the carb get the model # of ur carb and go to the nerest autoparts store for a new one..... good luck jack

[xs-style]

Im hoping you get a responce to this one. Ive got the same problem... only with a lawn mower lol

[kcackler]

We replaced all of the usual stuff back when we got her running a few weeks back (fuel filter, spark plugs, wires, distributor, etc..) so I doubt it's the fuel filter that's clogged. I'm going to take the fuel line tomorrow if it's warmer and see if we're getting any fuel through it when it's cranked. I'll update this when I find something out.

[74 C-30]

if she sucked up some muck from the older nasty gas tank, then it could clog the fuel filter

[kcackler]

I just had a thought...

The truck USED to have dual tanks on it. Now, however, there is only the driver's side tank. The switch is still in the truck, though I'm not sure if it's still functional. Could it be possible that it's trying to pull fuel from the passenger side tank, even though it's no longer present? (IE, maybe somebody hit the switch or some electrical glitch caused the unit to switch to the passenger side)?

I just went outside and made sure that the switch was on LH and tried to start again, but still nothing..

[kcackler]

73chevyman - You hit the nail on the head. This was a new fuel filter, but it was already clogged up with nasty crap. Took it out and she started right up, so we'll be replacing it when it gets a little bit warmer out.

Thanks!

[73chevyman]

glad i could help