i was going to replace the mechanical fuel pump on my 71 240z and wanted to know if i could use an electric fuel pump from a later 240z. i saw an electric fuel pump and mechanical fuel pump for sale on ebay from a 73 240z. do the later 240z's use both an electric and mechanical fuel pump?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33555&item=2427305531

'73s use both an electric and mechanical pump. If I remember right the electric doesn't turn on until the engine reaches 600 rpm for safety, if the engine stops the fuel pump stops. That way if in a crash the fuel line ruptures and the engine is stopped but the key on you won't be pumping fuel all over who knows what is hot or sparking while you are in the car wonding what happened!!

I would not eliminate the mechanical pump myself, but have no problem with adding an electric as a boost pump to the mechanical one.

oh yeah and if i could add the electric fuel pump would i need some sort of fuel pressure regulator as well? last time i brought my car to the mechanic he said i needed a new fuel pump and added an electric fuel pump and disconnected the mechanical fuel pump. the electric fuel pump he added was not made for my z but was some pump he bought from the parts store. he had tried it and it did not work out as it flooded the carbs. what is the normal pressure for the mechanical fuel pump? if i remember correctly the mechanic told me my mechanical pump was only producing around 4psi.

Wow that must have been some pump!

Considering the inlet size of the needle valve in the carb I find it hard to believe that you could put enough pressure on the needle to force the floats into a full bowl. It may be more of a case of the seat and needle being worn and gas bypassing causing the overflow.

A regulator wouldn't hurt and I would set it between 5-10 psi, that should give you more than enough flow.

Go to the U-Pullit and get a electric pump from a RX-7 , one that is NOT fuelinjected. It is mounted just in front of the rear axel on the drivers side. It will deliver plenty of volume and the pressure if I remember right is right around 5psi. I have been running one for over 2yrs. and cant remember the pressure. Your car is wired for a electric pump , just look up in front of the fuel tank on the passanger side . Install a inline filter before the pump . they dont like crud . by the way it was $15.00 . We tried one on a tripple set up on a stroaker and it provided plenty of fuel.

i used a carter electric pump by it self first it was fine only pumps 5 ps1 suits normal carbies with out a regulator

Now use a Holley blue pump but that one needs a regulator

In the jags that run conversion book they go into using a oil pressure switch to activate power to electric fuel pump so that it only has power when the motor has oil pressure.

Mick

beandip

did you disconnect the mechanical fuel pump and only use the rx-7 one or did you use both?

In a crunch once, I used a GM low pressure pump from the parts store, with no pressure regulator. The car also had a mechanical pump, but it would never run right when the electrical pump wasn't working.