Help needed with Diesel Delivery Issue

[MIKEVANK]

Hello.

I have a diesel heating system installed and its been running fine all winter up till now. The fuel feed for the heater is Teed into the fuel supply line from the Raycor to the Port engine.

Heater stopped running recently about 2 weeks after a new filter installed. Filter looks clean. There was a vacuum when I remove the Raycor lid. Re primed and the heater dies within an hour or so. Return line from the engine is shut off at the manifold.

I have tired feeding the Raycor from both the Aft tank and FWd tank with the fuel manifold selector. Same result on both. I don't think its a clogged pick up... but possible I suppose. Id like to test as much as I can to rule out other issues before I start digging into the tank.

Im getting kind of stumped here.

Boat is 1986 Hatteras 43 MY with Cat 3208s

Any help would be appreciated.

[oscarvan]

You have a vacuum gauge on the Racor? If not you need one anyways. That said I don't know how much the heater pump would be pulling and if it would be enough to register on a gauge that would be appropriate for the engine......