dalions

1994 F150 5.0L
I beleive I have a vacuum leak coming from the fuel pressure regulator area. I can hear a hissing sound coming from the fuel pressure regulator area. I have tried spraying starter fluid in the area of the hiss, but can't really tell if it is effecting the idle. It starts up first time every time but has a rough idle. I have recently replaced the plug wires, plugs and mass air flow sensor.
Before I replace the regulator, does anyone have any other suggestions?

Johnny Mullet

You gotta find that leak to smooth it out. I use Dragon Fire to spray around the area to find vacuum leak because it works better that starting fluid.

Could be an intake gasket.

dalions

What is dragon fire and where do you get it?

Johnny Mullet

n Fire is in a can just like starting fluid. Castle makes the product.