[jjjfw1955]

Help...... 1969 ElCamino vented cap, let pressure out drove opened cap same thing. Figured it was cap, bought new cap drove checked gas tank same thing vacuum?

 

[designo614]

Not sure if a 69 has a vapor canister, but if so, is it hooked up to your vent line from the tank? Or, is the vent line clogged? Somehow as gas is being sucked out, no air is coming in.

 

[pitts64]

They had a lot of issues with the 68-69 el Camino tanks. On my own 69 el Camino I switched to the 1971 tank with three vents across the top front of the tank. I plugged both end outlets and put a steel fuel filter with 3/8" ends. I put a loop in the hose that goes inti the fuel filter. Then I used a vented cap. All the fume and vacuum issues went away. Before I did this, I had terrible fume issues. The cool old dude I bought the car from, lost his sense of smell from Agent Orange in Nam back in the sixties. So he never knew there was an issue. Besides, he gave me such a great deal I still would of bought the car.