I want my, I want my, I want my MPG

[sblake01]

Or even Donald F a g e n's 'Trans Island Skyway'

(the things you have to do here to avoid censorship!)

[mlc240z]

LOVE IT,Bill!!

[beandip]

I got the idea from a Toyota advertisement that i saw a few days ago, and a little bit Dire Straits never hurt nobody.

Anyways, I am planning on replacing my fuel pump. This seems like a good idea because the one on the car currently is old, really old. It sat on the car for 12 years without pumping an ounce of gas, I imagine that the diaphragm (sp?) is cracked.

I was thinking about just replacing it with an electric fuel pump. Any suggestions as far as a good pump to use.

I searched the forums for MPG and found most people get about 15-20 in the city. I found I got 12.5 mpg because I went only 150 miles and my car took 12 gallons at the pump. The driving was city with a little freeway (a couple miles every trip). Sometimes I let it warm up for a few minutes, and other times I just take off, either way the choke is only on for a few minutes.

Thanks for the replies.

BACK TO THE TOPIC . If you suspect the pump is leaking fuel into the crank case . Do change the pump , but by all means change the oil and filter. the gas will thin the oil and you will burn up the engine. If you are running lean as you have said , cure this ASAP or you will burn the valves. As for a fix to go to a electric pump , I have been running a RX-7 pump from a '80 Mazda for going on 4 yrs. paid $15.00 at the u-pull-it. Pumps 5psi. and is quiet. I just made plate out of 1/4'' aluminum the shape of the original pump and bolted it to the head to seal the port. Now I am running SUs on a ZX engine with the same pump. With the L-24 I was getting 23 on the hi way and 14 to18 in town depending . Speedo is not accurate so I don't know what the MPG is now .

[VaGuS510]

Thanks, I searched for electric fuel pump and found the stuff about the RX7 pump. I think i am going to do that. I might check the wrecking yard near me, but I don't always trust stuff from those places. If I find one that looks to be in good shape I will grab it. Also, I have a 73 240z so could i just wire it using the wires that are down there for the original pump? That pump is supposed to run when the engine is over 600rpm right. Seems like it should work to me. Anyone have experiance doing this? Thanks.

[VaGuS510]

All you have to do now is record it hls30.com. I hope your voice is better then mine.

[Dtsnlvrs]

The s-30 chassis was pre terminated for an electric fuel pump, true. But that is all it was, the wiring is there at the tank, but there is no power to it, one must find the wiring under the dash (above and right of the glovebox for LHD models) and wire in a relay and power it. I use a Holly elec pump mounted at the tank...feeding triple webers.

[Arne]

The s-30 chassis was pre terminated for an electric fuel pump, true. But that is all it was, the wiring is there at the tank, but there is no power to it, one must find the wiring under the dash (above and right of the glovebox for LHD models) and wire in a relay and power it.

True for '70-72 models, but the '73 240Z (and the 260Z as well) did have an electric booster pump near the tank in addition to the mechanical pump on the head.

[Dtsnlvrs]

True for '70-72 models, but the '73 240Z (and the 260Z as well) did have an electric booster pump near the tank in addition to the mechanical pump on the head.

Thanks for the correction Arne, I had forgotten about the elec pumps used in 73-74. BTW I have seen 73's without the elec pump, and with the factory wiring still taped, and tucked away. But back to the question at hand. Yes you should replace the mech pump right now, drain and flush the oil sys (standard oil & filter change followed by just oil change after 100miles.) Then figure out what if any elec fuel pump setup you are going to go with.

[Carl Beck]

The s-30 chassis was pre terminated for an electric fuel pump, true. But that is all it was, the wiring is there at the tank, but there is no power to it, one must find the wiring under the dash (above and right of the glovebox for LHD models) and wire in a relay and power it. I use a Holly elec pump mounted at the tank...feeding triple webers.

Hi Russell (everyone)

Actually there is power for the rear electric pump in the factory wiring harness. When you find the wire that goes from the dash area to the pump - you'll find another wire right beside it. Both have female spade ends, so you need to get/make a male/male spade connector to bridge them together... that will send power to the pump.

The "problem" is there is no safety circuit in the early factory system - and most likely one reason it wasn't used in the US. No automatic shut off with loss of oil pressure, no automatic shut off in an accident...

If you install a relay... you want to activate it only when you have oil pressure... or better put a timer on it so that it runs with no oil pressure for say 5 seconds at start-up, then shuts off any time after that - if no signal from the oil pressure sender is present.

Electric fuel pumps are great - but you don't want them running when they shouldn't be.

FWIW,

Carl B.

Clearwater, FL USA

http://ZHome.com

[beandip]

There was a discussion on this a while back. What I have done is to put a tee where the sending unit for the oil sending unit is and installed a pressure switch that activates only after 5 psi is reached. This is wired into the pump circuit. The engine starts and runs off the fuel in the carbs and within a couple of seconds after start up the fuel pump starts running. The only down side is if I run out of gas , then I will need to bridge the contacts to have the pump fill the carbs , not hard to do . My 2 ¢ Gary

[Dtsnlvrs]

Hi Russell (everyone)

Actually there is power for the rear electric pump in the factory wiring harness. When you find the wire that goes from the dash area to the pump - you'll find another wire right beside it. Both have female spade ends, so you need to get/make a male/male spade connector to bridge them together... that will send power to the pump.

It is funny you mention that Carl. While I was digging around in 240ZTT dash yesterday (removing and cleaning all heater ducts, fan box, heater control box etc.) I was showing him the pre-terminated wiring, and marveling at the cleanliness of his harness, ie. no ugly PO splices. I then noticed some terminal ends that were taped up near the fuel pump wiring and wondered what they were for. I did not test them but I imagine that they are power for the pump. As far as safety goes, I have a oil press switch wired into the circuit. I bypass it with a momentary switch for engine startup.

[VaGuS510]

From what i understand my electric booster pump only goes on when the engine is above 600 rpms, is this true? If it is, then wouldn't it be safe just to tap into that wiring? I know for a fact that it doesn't run when the engine isn't running.