could someone please help. 92 f150 5.8 dual fuel tanks. first thing in the morning it starts good. if it idles for about 3 minutes and I push the gas peddle down it dies and will not start unless the peddle is all the way to the floor then it pours black smoke, from flooding I assume. new idle air control, new coil, new fuel pressure regulator, new fuel filter, eec taken to autozone and tested on the machine that heats it up. after all the new parts i checked the fuel pressure with it at idle and got 40 psi. key on engine off fuel pressure 8 psi. I assume this is not right. truck runs the same way on both tanks. Im not a mechanic by no means. I hate to spend more money on a fuel pump. Im trying to reason this out with no success. can both pumps be bad (only 2 pumps) anyone who would be willing to share their wisdom would be greatly appreciated!!!

 

So the system makes 40psi at idle? Is that with vacuum attached to the regulator or removed?

And you say it only makes 8psi with the engine off. Is that after 1 cycle of the key or is it the same no matter how many cycles you give it? Does it hold this pressure or does it bleed off instantly?

Do you have the fuel transfer problem between tanks?