I have a 97 F250 HD with a 460 in it. dual gas tanks. as soon as I go to start it, it will go up to 1500 rpms then die immediately. sometimes it will run for a second(studdering as it goes). when I hit the gas it will studder and not pick it up right away or it will die faster. it started ths a few months ago and has gotten progressively worse to where i havent driven it. I replaced the fuel filter and cleaned the air filter. I bought two fuel pumps but havent installed yet... WHAT COULD IT BE...? Any help would be greatly appreciated

 

Welcome to FTE Babe460.
Does this happen when warm or cold? Does this happen on both tanks or just one in particular. It sounds like the fuel is draining back towards the tanks. I had a '77 F350CS with the 460 that did the same thing. Mine ended up being the tank switch solenoid. There are one-way valves that you can install in the fuel system that may help or else you may have to install those fuel pumps. You might also want to check in the 460 engine forum for some help and answers. Good luck.

 

some new developments... I tried to start the truck today and it died same as before. However, when I hit the gas immediately after starting it, it ran ok at high rpms. When I let off the gas it idled normal at 900. When i shifted into reverse the idle dropped and wanted to die. shifting back into park made it ok again. Also when it was idling, I heard a rattle coming from what seemed like the cat... could a clogged converter make the engine do that???

 

It has also been warmer the past few days...