The hose for the return line needs to be tucked in to the pump bowl. I've seen the same problem when its been reassembled with that line loose outside the bowl.
Its not unheard of for the pump to be assembled correctly and everything to look right but it still doesn't work. There's legend of a mystery pipe inside the tank which can come adrift and also cause the problem. People have swapped the complete fuel tank to solve it.
Its plausible that the Marelli pump has the stub but not the internal gubbins to push fuel through it. If it was reverse-engineered from the VDO unit the point of that outlet might have been missed and its simply a moulding artefact. Having not tested it myself I couldn't say whether it actually works as expected.
The VDO pump is not really that expensive in the scheme of things.
|