Mechanical Fuel Pump 73 240Z

[MAX]

Help,

Before re-installing the mechanical fuel pump on my 73 240Z, I checked it to see if it was still working. I actuated the lever several times and noticed that there was NO suction at the intake line. I have had it off the engine for 2 years while the engine was removed during body restoration and painting....and it worked fine prior to that...

Any thoughts as to what may be the problem and how to correct it..

Many thanks

MAX

[kenz240z]

Well, it's only 3 bolts that mount it. Put it on the engine and see if it pumps gas. If not, then buy a new one. I got a Kyosandenkei brand fuel pump on ebay that looks like the original.

If your Z has AC, test the fuel pump before you mount the compressor.

[74-26Ounce]

Help,

Before re-installing the mechanical fuel pump on my 73 240Z, I checked it to see if it was still working. I actuated the lever several times and noticed that there was NO suction at the intake line. I have had it off the engine for 2 years while the engine was removed during body restoration and painting....and it worked fine prior to that...

Any thoughts as to what may be the problem and how to correct it..

Many thanks

MAX

Hi Max,

If it’s been sitting for that long, the diaphragm may be split and or the valves under the top cover might be stuck. When reinstalling the diaphragm, it needs to be flat so you need to hold the lever in partway (against the pressure of the spring) before tightening down the screws. I recently did one that still didn’t pump fuel so I installed it on the car, turned the engine over so the lever was touching the fuel pump lobe at about the half way mark, then slightly loosen the diaphragm screws and then re-tighten them so the diagram moves up and down an even amount. Also fill the intake line with fuel to help prime it.

[MAX]

Thanks to all for the great suggestions.

The diaphragm isn't split but it seems rather stiff.

I will check the valves tomorrow to see if they are stuck. I didn't think of doing that..

As far as installing it and letting it try to pump gas, I'm not quite ready to do that yet...I just reinstalled the gas tank but don't have all the lines connected up yet...And I have a lot of other things to put back on the engine as well...

Prior to installing the fuel pump about 3 years ago I did the same sort of test and I could definitely feel a suction at the input line....

I'll keep you all posted on the progress

thanks again