Truck won't run unless tapping on the fuel rail

[Pbourgeois]

I have a 1985 4runner 22re. I've put a new engine in a long block and have found that the only way the truck will idle up and run is when you take a screwdriver, and tap the center of the fuel rail. I've checked fuel pressure, fuel pump is new. changed mass air flow sensor, knock sensor, igniter, new injectors checked pressure drop on each. The fuel pressure regulator is also new. I just can't fathom what my problem is, and why tapping the fuel rail only will make it idle and run fine for about 6 minutes or so. Please tell me someone has had this same issue before and can help. I'm ready to set fire to it as it is.

 

[fourwd1]

What about the pulse damper, that's about the only thing left on the fuel rail.

 

[KidVermicious]

What about the pulse damper, that's about the only thing left on the fuel rail.

Exactly what I was going to suggest after seeing the title.

 

[Pbourgeois]

Okay fellas I appreciate your info I am going to break Down the fuel rail check that damper and see if maybe a dirt dobber built a nest in side while I was swapping engines.

 

[SV_Dude]

If you see any debris in there you may want to consider getting your fuel injectors checked out.