84 k30 6.2 fuel system (leak hunt)

[KamperBob]

I'm hoping y'all can help set proper expectations. My 6.2 developed a fuel leak that I'm trying to chase down. From research I've pieced together some information. If I understand correctly, the primary fuel circuit (stock) would be a follows. From dual tanks supply and return lines meet at the selector valve. Then a single pair goes up under the hood. The supply line goes on to the lift pump (mechanical) on the front passenger side of the engine, inside the frame rail. From there fuel flows up to the filter on the firewall. Then over to the IP on top of the engine, under the intake manifold. Presumably entering the IP at the rear. The IP return line (probably also rear) goes back down to the tank selector. Do I have that correct? Or am I off target somewhere? Any visual aids would be a major blessing to lay eyes on everything under a less than ideal work area in eleventy some temps. Thanks a bunch!

 

[Blue Ox]

Pretty much. The return combines all the injector jumpers and the pump (top) return to a crossover tube that bridges across the front of the engine like an upside down V and has a barb near the passenger frame rail near where the supply line for the lift pump goes.

The injectors have a boot on the back return barb and jumper hoses between them that meet the crossover at the front of the engine.

 

[Ricko1966]

Are you leaking fuel or sucking air?

 

[Ricko1966]

Are you leaking fuel or sucking air?

That was a serious question I had a diesel that I couldn't get the IP to prime because it was sucking air instead of fuel. No external leak visible. I just wondered what he is chasing.

 

[KamperBob]

That was a serious question I had a diesel that I couldn't get the IP to prime because it was sucking air instead of fuel. No external leak visible. I just wondered what he is chasing.

Both. I couldn't see the source but it appeared to pee fuel from behind the IP. Which makes me suspect the supply line first.