2 Fuel Pumps on a '73?

[DocBombay]

Can anyone tell me if and why my '73 I just bought has a 2nd fuel pump back by the tank? Did it come like this? Why?

Thanks

[2ManyZs]

Hmm, good question..... It should only have one unless a PO put it there for some unknown reason. Maybe they were having trouble and thought two was better than one? Never know what a previous owner was thinking when they do some of the things they do to a car.......

Actually the 73's didn't have an electric pump at the rear when they were sold until the recall for the vapor lock/driveability troubles, at which time Nissan recalled them and put a kit on them. The kit consisted of the electric fuel pump, 7 bladed engine fan, and the insulation for the fuel line, and maybe one other thing that I can't remember......

[240ZX]

Interesting....my 240Z (s/n 02126) has factory wiring and a mounting position for an electric fuel pump, even though they did not come from the factory with them! Did the Euro or Japanesse models come with electric fuel pumps or what? Anyway, it sure worked out nicely when it came time to install my Mallory fuel pump.....the wiring was already in place!

[DocBombay]

Yep, must have been a recall, sure looks factory. That seems to jog my memory. It is disconnected now and the car runs fine. Hope is to make it a convertible GT and fun car street and track.

[Bambikiller240]

Originally posted by DocBombay

Yep, must have been a recall, sure looks factory. That seems to jog my memory. It is disconnected now and the car runs fine. Hope is to make it a convertible GT and fun car street and track.

In CA many of the 73 240Z's were fitted with the electric fuel pump/fuel line blankets by the dealers. This is a fairly common thing to find on 73 Z's in CA (also found in other area's of the US as well, but I don't know how common)

[Ed]

My 73 (which was a california car) had 2 pumps. One electric by the tank which from the looks of the wireing looks factory. And another mechanical pump on the head.

[sblake01]

According to 'Haynes' the supplimentary electric fuel pump was fitted to 260Z models. But I have also seen the same exact factory installed pump on 73 240Z's.

[gramercyjam]

My '73 had the factory looking install for the electric pump and wiring harness too. It must be pretty common.

[ChrisA]

Ditto to John, My 73 has factory wiring back to the electric pump. Everyone knows about the filter in that pump right? Mine was full of crap when I bought the car. Ran bad till I replaced the filter. Makes a mess when you drop the cap off the bottom.

I think the post about the recall is right. I had the aluminum covering on the fuel rail and lines when I bought it but took it all off when I switch to the good carbs. No vapor lock for me. Gets over 100 in the summer here.

[dponder]

will S.U.'s be properly fed with just the electric pump? I am installing a p79 and it is not drilled for a mechanical pump. Is the return line necessary is the mechanical is bypassed?

[ChrisA]

My setup is 76 L28E with 71 carbs and manifold. Holley electric pump at tank/Mr. Gasket pressure regulator under hood. 71 fuel rail with return.

To answer dponder's question: I dont think the stock electric pump will be enough to feed SU's. It was a booster for the mechanical pump. And yes you will need the fuel return system.

[gramercyjam]

Never ran the electric pump alone with the SU's, but I am using the stock electric pump alone to fuel triple weber 45's and it is more than adequate. I wouldn't think SU's would require more fuel volume or pressure. I agree that retaining the fuel return is the preferred configuration as it has an orfice that acts as the fuel pressure regulator.