thanks all. Six5, the return line is not giving me anything but it's pumping fine from the fuel pump. no error codes on the display. So I think it's most likely the injectors - that's my next job...
Pez, I'm sorry for the long delay. I was out of town with many distractions. 🙃
I must disagree on your injector suspicions. True, they may need to be serviced, but they are not preventing the fuel from flowing through the return line.
In order for the fuel in the rail to return to the tank, it must pass through the fuel pressure regulator (FPR). Since you are seeing no fuel from the return line, that says the pump pressure is inadequate. The pump is running, but it is weak. I have experienced the same issue on my TLR.
If the pump can't generate enough pressure to open the FPR, then it is also providing low pressure to the injectors. That's why the engine won't start as it should, and you need the starting fluid to bump it over.
The FPR is a simple spring loaded valve, and it rarely fails. Therefore, the most likely problem in your system is one or more of the following:
- Weak fuel pump
- Clogged fuel filter
- Perished fuel lines inside the tank.
Let us know what you find please.