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Did you install an inline pump and this problem happened immediately afterward? If that's the case then the inline pump may be creating too much pressure and it's overcoming the fuel pressure regulator, or it's possible that fuel pressure is too low.
The first thing you'll need to do is check fuel pressure. With the engine running and regulator hooked up you should see 35 PSI, with the regulator vacuum line unhooked it should be 42 PSI. If you see more than this then your new pump is pushing too much fuel, it will either need to be replaced with a suitable pump or another regulator installed to bring pressure down.
If pressure is low then either this pump isn't strong enough, it's power or ground feed is weak, or there is a restriction in the tank causing low fuel volume.