99 f1 4.6 2wd 221k

So every morning when I start the truck it sort a stumbles like it's having trouble starting but after a few sec it idles perfectly fine and drives perfectly fine. Only at start up, and it's fine when it's warmed up.

Any ideas? Thanks

 

leaking injector
leaking manifold
leaking head gasket

 

^^^^
Leaking fuel pressure regulator

 

Thanks mbb

No fuel smell (ever)
I've replaced the intake manifold gaskets twice.
I have no signs of leaking hg.

 

Would I smell fuel if this was the problem?

 

I should add, that it does not have issues starting, it's starts 100% of the time. After 1-2 sec of stumbling it idles smooth as butter and has no issues driving anywhere.

 

No, the regulator likes to leak into the vacuum hose. This floods the motor (once the unpsent fuel is gone, it starts). You can pull the vacuum off the regulator after you shut it off, and watch to see if fuel comes out the nipple.

 

So basically after I shut off the engine there shouldn't be any fuel coming out of it?
What if it's been sitting over night?

 

Yes, and yes. I've even rigged up a jar with a short piece of vacuum hose coming off the nipple before.... then see if the jar has fuel in it in a few hours.

 

Thanks white. I'm gunna start checking it out.