This will not work with efi. Tried it, don't work. I am running 60 psi tho. The problem is that your adding pressure to the fuel by doing this. At low rpm when your not using very much fuel most of it is returned. Returning fuel to anything but the tanks is also returning pressure.So your fuel pressure will be a lot higher and when you dial it back down and bring the rpm's up you wont have enough pressure. Your working your fuel pump more than you need to because you not relieving any pressure and will shorten its life.Also with that extra pressure going back to the line as a return it is also possible to push fuel back the other way causing a shortage of fuel. I'm very surprised that Marcsrollin dosent have any issues with that yet. Having more fuel than your burning going back to the supply line just doesn't make sense to me.

I'm a little late getting in here but...Mine did the same thing this spring. I had replaced the filter and added a water separator. Turned over a few times and no fuel. None in the filter and none in the lines. I added some fuel to the carb with a squirt bottle and turned it over a few times until it fired up. After about three or four rotations of adding fuel until it died again I noticed fuel in the filter. Mechanic friend told me that I was on the right track cause the mechanical fuel pump had to be turned over longer to get it to pick up when the lines were completly empty. I had thought I was going to have to change out the pump but all seems to be working fine now. Will probably go with an electric eventually but...,.
Dave