4000 Quattro fuel circuit overheats

[David Vanden]

This is probably out of my league, but the fuel circuit overheats or seems to on my 4000 Audi Quattro.  It has been suggested that the fuel pump is getting clogged and that the pressure  regulator needs to be adjusted; or that the inlet pressure is more than the outlet pressure.  Any other hypothesis.  I ran the inlet outlet pressure theory  by the mechanic and he didn't think that was it.  I will probably end up taking it to him anyway, but I wondered if anyone had any other ideas?
David