Just got a '96 F-250 crew cab short bed with duel tanks. Filled front tank and put cap back on. Was going to put some in rear tank but as soon as I removed the fuel cap fuel gushed out of filler tube. Check engine light is on now. Got a code P0443. Evaporative Emission System Purge Control Valve Circuit. Is there some kind of check valve in the system that goes bad?

 

Almost sounds like the fuel from the front tank was returning to the rear tank. Research the switching system and controls for the dual tanks. I had a similar issue with the older system in my '88 F150. My system uses fuel pressure to direct the proper supply and return, where yours should have an electric solenoid valve, I believe. Give that a look, anyway.

 

Yes it sounds like you've got the fuel transfer issue. The check valve in the rear tank is to blame as I understand it.

Good news is, it'll seem like your fuel economy will go way up once resolved.

 

Thanks, I'll have to crawl under there and see if I can spot anything.

 

No electric solenoid valve. All of the valves are in the FDMs (Fuel Delivery Modules) in the tanks. You likely have a bad FDM in the rear tank.

 

Is this a gas or diesel truck

 

It's a gas 460
Thanks for all the replies.