[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.