1965 C10 LBZ - crank no fuel pressure

[2mas]

Hi guys,
Thanks for letting me in to this forum! I'm putting a 2007 VAN LBZ into a 65 C10. The engine is in the chassie and has been
started several times the last year during the chassie build. But now after having the engine out for 6 months, it will not start.

A friend helped me to read out the live data and error codes via the OBD2. It looks like fuel pressure is not building up in the fuel rail. It is on 34psi, not moving at all, not even during crank. When I disconnect the pressure sensor, value go up to 29000psi.

I've done this
1. I have excluded the filter and lift pump. I have a gallon of fuel next to the connectors on engine back side. There is flow in the return line.
2. Disconnected the the CP3 FCA

If the rail pressure sensor is broken, should the engine fire when the FCA is disconnected?
Any suggestions on next thing to test?

Thanks!
/Thomas

 

[2mas]

Update.
Removed the return lines on the injectors. I see no return flow from the injectors, but there is quite a lot of flow in the return line, especially when running the lift pump. Should there be flow there?

/Thomas

 

[Burn Down]

Update.
Removed the return lines on the injectors. I see no return flow from the injectors, but there is quite a lot of flow in the return line, especially when running the lift pump. Should there be flow there?

/Thomas

Return fuel is normal, what the injectors and cp3 can’t/don’t use returns to tank on that hose.

What does the fuel pressure do while cranking if you unplug the fuel pressure regulator “wire connector on the back of the cp3”?

 

[2mas]

Nothing changes when disconnecting the fuel pressure regulator.
Did the bottle test and measured the pressure sensor. Looks ok.
I'm thinking I have large amount of air in the rails maybe?

 

[2mas]

Problem solved. Disconnected fuel line on one passenger side injector. Cranked three times until fuel was seen. Reassembled, then crank and start!



/Thomas