Fuel system question for Maxima

[DMS]

I have no basis for comparision so I need some help. Is there a fuel pump near the rear off the car? Or is the entire system ran from the high pressure pump?

Im putting together my Z and wasnt sure if I should put a helper pump at the rear of the car. I honestly dont beleive I should but I cant be sure. Seems like it might just inhibite the flow to the high pressure pump.


thanks

Ray

[83_maxima]

The IP has an internal pump that pulls the fuel from the tank.

[asavage]

The gasser (L24e) has a typical high-pressure pump external to the fuel tank and to one side of it.

The diesel (LD28) has a vane-type lift pump internal to the IP, at the front end of the IP. With D2, it rarely fails. With other "fuels" or dirty fuel, the vanes and vanes housing can wear out. The vane pump not only pulls fuel from the tank, it also pressurizes the IP housing, which is critical to timing control on the VE-style IPs. So if the lift pump fails, adding an external lift pump may get the engine running but it will not allow the timing controls to work correctly and the timing will become very advanced retarded. IOW, if it's broken, you have to fix it, not patch it.

Some members like adding an additional, external electric lift pump. I don't feel it's necessary: electric lift pumps are one of the most trouble-prone devices on a car, and the advantage of one is pretty much restricted to those rare occasions where you might run the tank out of fuel -- which is a no-no for any vehicle. Gasoline fuel-injected vehicles have fuel pumps which are lubricated and cooled by the fuel, so running them with aerated fuel (ie nearly out of fuel) is bad. Carbureted vehicles with mechanical, diaphragm lift pumps are designed such that the stroke of the diaphragm is minute in normal conditions, and when you run them out of fuel they will suddenly have to full-stroke, and that will push a marginal/old fuel pump over the edge into failure -- running out of fuel can ruin an otherwise working pump.

A couple of members have had the mechanical priming pump at the fuel filter head fail. If I could not obtain a replacement priming pump, I might consider an electric lift pump -- and leave it off until needed.

[davehoos]

i cant remember,but if the fuel tank is behind the rear seat high in the boot i wouldn't think that you need to go to much trouble. just check that the surge pot and filter in the tank is suited to diesel. i would remove any filter from here and use at least a 8 mm pipe[5/16].

if the tank is low and thin it may be needed to add an additional swirl/surge tank and a low pressure transfer pump.these types of tanks can be slim and air and frothed fuel is drawn into the system,it collects in the filter until enough flows through to stop the vane pump working.i had problems driving up hill at highway speeds,after a mile you may have fuel starvation to the point that the engine stops,if this don't happen when you first test drive with half tank it shouldn't in the future.

gasoline engine need a high return of fuel to the tank in many applications to work,LD28 returns only a small amount so the hoses need to be good to stop air leaks.