Engine/Transmission (1994 - 1998) Fuel return line question

[The3rdAmigo]

Can someone explain WHY a fuel return line leak causes hard starting?



I can understand the supply line causing problems, but I don't get what difference it makes if the return line has problems. It just goes from the O/F valve to the tank. I like to know the why of things.

 

[wildmanben]

I dunno but mine did the same thing. Probably because the lift pump has a harder time building system pressure when there is a leak in the system...

 

[Dieseldemon]

It unprimes the engine when you go to start you have to reprime.