noise in gas tank

[blumule]

leaving work today my 69 just died on me. coasted into a parking lot and stopped.heard the strangest sound . at first i thought a jet was flying over.then realized it was a swooshing bbubbling sound from behind my seat in tank. lasted about a minute then stopped . truck never started back. havent had time to investigate. im thinking pump. what do yall think?

[chad67]

That almost sounds like the tank was not venting correctly. If so, the pump would pump until it couldn't overcome the vacuum. If it died under those circumstances, it would suck the fuel from the lines back to the tank. Try running it without the gas cap on (parked, of course) and see what happens. You may have to pour a little gas down the carb to get it going.

[BRUTUS_T_HOG]

Clogged gas cap vent. Run it without a gas cap to verify then get a new VENTED gas cap

[blumule]

that was my first thought. i removed cap and tried cranking but gas never entered fuel bowl. i have a clear in line filter. want to mention a tapping sound on fuel line behind seat and a woosh when opening cap. i did purchase a new cap last month thinking this would help. i assumed this woosh was a normal thing as my other vehicle do it.

[hazelnut]

Just a thought, Theres two different caps for our trucks. One's vented, the others not. 67-69 vented,70-72 not vented- 70-72 a vent line runs to the front of the right frame to a charcole filter.

If its sucking air when you pulled the cap i think the parts store gave you the wrong year cap.

[vwfreak]

Still have a filter in your fuel pump? Might be clogged if venting tank still won't let fuel feed.

[colnago]

want to mention a tapping sound on fuel line behind seat ...

I get this in my truck when the tank is getting low, especially if it's cold outside. Really irritating tap-tap-tap. But right now, I use it as a reminder to get to a gas station! Better than a dash light ... and it's stock!

+1 on the gas cap and the clogged fuel filter.

Joseph

[blumule]

ill figure it out this weekend. always like to get some helpful thoughts. my truck is a 69 and definately has the vented cap. i previously had the locking cap and it never sucked air,

[chad67]

That wooshing sound was the vacuum in your fuel tank sucking all the fuel from your lines back to the tank. As long as you have plenty of gas in the tank, dribble a little gas down the carb and then start it. It should fill the lines and prime your fuel pump. It may take a couple of times to fill your carb, too. Btw, don't try dribbling gas in the carb while it's running, any backfire will prove to be very "interesting".

[R.Smith]

I went thru this with a cap that was supposedly vented but, wasn't. I replaced 2 fuel pumps before it dawned on me that the vaccum created by the non vented cap was causing the fuel pump diaphram to rupture.

[blumule]

The gas cap not venting properly is the only logical explanation. Once I cracked the cap open I expected pump to refill my bowl. When it didn't I have to wonder if it didn't ruin my fuel pump. Ill.pullnmy gas line tonight and see.