92 Asto AWD vin "W" bad milage continues part 2

I have changed the spider and nut kit on my 92. This has helped the van to run much better and smoother. When I took the plenum off I saw that there was a leak somewhere on the passenger side of the engine. However, I am getting 10 mpg in the city and got 13 mpg on highway and city. I have no idea what to do now without spending so much here and there. The fuel filter has been replaced as well as the plugs, wires cap and rotor.
The fuel pump when the key turns on puts out about 62 psi and then settles at 59. I think that the fuel pump is at borderline but I am not sure if this can hinder the fuel economy. Does a low fuel pressure tell the engine to put in more gas?
Any insights on this will be greatly appreciated and I appreciate all the help thus far.
Ryan