MAX

Thanks for your replies Nahurry and Walkjw, So...am I to understand that there is a relay that controls the voltage to the fuel pump. If so, what activates the relay and can anyone identify which one it is? I do have a oil pressure sensor but not an oil pressure switch. And I assume that the oil pressure sensor just drives the oil pressure guage? I don't see any such relay in any schematics. I measured 12 volts at the in line fuse contacts when the ignition switch was in the on position (assuming I had the correct in line fuse). But the voltage was not getting to the connector in the back which plugs into the fuel pump. But like Nahurry said, maybe there is some bad wiring along the way.....and I will check this out.... thanks

Ed and all, I too am installing a new electric fuel pump on my 73 240Z and I'm trying to find the physical location of the inline fuse holder. I have found an inline fuse holder in the center console near the fuse box and it has a solid green wire on one end and a black/white one on the other....Is this the correct fuse holder? By the way I'm finally getting around to replacing the dealer installed electric fuel pump which died years ago and I too forgot where the correct wiring was... I do have the correct wires in the back of the car near where the original fuel pump was...However, I am not getting any voltage there when the ignition switch is in the ON position...So I'm wondering if there are other connections in between. thanks

It is still frog ugly... I think they should take the "Z" off it's name cause that it ain't.

Hey DZR, I'm from Minnetonka. Where abouts are you from in MN.. Are you in the ZOOM club? Yes, my baby is tucked away in the garage too and we both are anxiously awaiting spring. And a very Merry Christmas and Happy New Year to all as well.... Randy

I too have had the same problem with a fuel leak after filling the tank. My leak turned out to be the vent hose that connects on the driver's side of the tank right next to the muffler. It was leaking right there about an inch away from the end of the nipple. Just as Darrel described in the last post.... Prior I had used the POR15 cleaning and sealing kit to redo my tank. It works very well....But be sure it doesn't clog any of the fuel or vent lines..... Good Luck....

thanks Steve, I'll have to trace out the wires coming from the fuel pump and see where they go up under the dash..... And good luck to you. Randy

Hey Steve, Thanks for your reply.. Is that your 240ZG in your Avatar...Very awesome Hmmmmmm. Well, I think it is time I get out my voltmeter and do some testing. Going from the wiring diagram I thought I had found the correct in line fuse ( 20A ) which is pretty much under the radio and lying in front of the fuse box....But perhaps this isn't the correct one. ...I also find 2 other in line fuses back in the wiring. And from the diagram it appears that one goes to the accessories relay and the other to the rear window defroster... I have owned this car as new and can remember taking it back to the dealer in the early 70s and they installed the kit to correct the fuel line vapor lock problem. The kit included an electric fuel pump which had since crapped out and I removed it years ago and am just now completing a restoration and installing a new one. But it seems from what you and others are saying that there is another T in the wiring and that no fuse was installed for the fuel pump in the original place....I'll have to dig further into the wiring behind the radio. By the way I just ordered a Mallory 4070LP electric fuel pump which is supposed to be internally limited to 4PSI. Others have commented that is the quietest one out there. Randy

Hey Guys, I'm a little behind the times but am just now getting around to installing an electric fuel pump on my 73 240. I agree with everyone's assessment about the safety concerns of shutting down the fuel pump in the event of a wreck. If I am correctly interpreting the 73 wiring diagram from the Datsun Shop manual, it appears as though Datsun figured out a solution to this without the need to add any switches (oil pressure or inertia). OK, so here's how I see the wiring in the book and perhaps someone can tell me if this is correct. I haven't taken out a volt meter and verified this yet. In any event it appears that the power for the fuel pump comes from the alternator and thus if the alternator is not turning there won't be any voltage to supply the pump. From the schematic it looks like the green wire from the pump goes through a 20A in line fuse located under the radio area. A black/white wire exits the fuse and makes a T. One run goes to another 20A fuse in the fuse box and then on to the voltage regulator (I'm assuming this is the un-regulated voltage input to the regulator). The 2nd split off the T goes to position 2 on the ignition switch. Just for the record the black/white wire also feeds several other places as well....Nevertheless, it appears that position 2 on the ignition switch gets voltage from position 3 when in the RUN or START position. Now....there is a White/red wire going from position 3 back to one of the contacts on the alternator....(as well as other places). So is this what I think it is. Does the alternator indeed feed unregulated voltage to various places in the car via the ignition switch....ie. places like the fuel pump.... Please help as I could certainly use some better eyes looking at this as well..

It just breaks my heart to see this once proud car end up like this.....

Can we get the administrator to send this thread to Nissan?

Slobound76: I just realized that I had a mistake in the link for Nissan Sport Magazine which I posted a couple days ago... Here is the correct link: www.nissansportmag.com I think it is a pretty good magazine but I was much more interested in its predecessor, Sport Z Magazine, especially the first couple years that concentrated more on the original Z cars. I will continue to get the new magazine even though it has a lot of coverage on other Nissan and Infiniti vehicles. It seems like they are still committed to having articles on the older Zs.

Check out the following link: www.nissansportsmag.com

you're right Tomohawk. I didn't read the add closely enough...

Well, I know it is NOT out of a 73 since I just removed mine to install a new radio. The one from the 73 is a lever type switch and not like the rocker style shown there. While we're on the subject. I'm trying to figure out where to mount my antenna switch since I'm replaced the old radio.. Presently it's connected but just dangling out from behind the console under the dash on the drivers side....... Anybody have any thoughts as to where to mount it?

I have the Weber DGV carbs as well and I initially had the vacuum line connected ou to the manifold. I found my mistake while monitoring the pressure to the vacuum line on the carb....sure enough it was dropping way down when I opened up the throttle. There is in fact a place on the carbs for the vacuum line to be connected. It is on the front of the carbs just behind where they bolt up to the manifold. Weber recommends connecting it up to the front carb.

Hey Marty, Well, I never checked with Pertronix to see if the Ignitor 2 was compatible with the Zs. I will look into that... I like your idea of installing a black box inside the car rather than under the hood. Are you thinking of under the dash? Let me know what you come up with. Good luck

I'm having an Orgasim.......over that 2000GT. Now that is fantastic. I love those long sleek lines. Reminds me of a cross between the older Jags and the 240Z with the GNose. Now if Nissan could do something like that and smooth out the front and back end designs a little....they would really be onto something.

Hey Zbane, That looks like a great idea. What is the A pillar? thanks

I have a friend who is an X Nissan mechanic and he has a new 280ZX distributor he wants to sell me...I'll have to verify with him if he also has the E12-80 module.....

Hey Dave, I like your designs....for your next project would you give some thought for a design to mount a pair of small speakers up front but not in the doors. Perhaps just tweeters..... I think that would make an awesome set of quad speakers if paired with those in your current design. MAX

Hey Guys, I should have included this link to the Pertronix Ignitor 2 product. It looks like it micro based and can actively control the length of the dwell and spark energy. does the E12-80 have any intelligent control that can vary the dwell like this? http://www.pertronix.com/ignition_products/ignitor_2.htm

I am looking to update my 73 240Z's ignition system from points to an electronic one. I'm looking at various options such as the Pertronix Ignitor 2, Crane XR700/XR3000 or the 280ZX distributor with the e12-80 module. I've read through the varioius archives on this site and still haven't come to any conclusion: I am leaning to the Pertronix or the 280ZX options....one reason being that the additions don't involve adding an extra box under the hood...perhaps this is not a very good reason though... 280ZX: In the research I've done it appears as though the 280ZX option may not be compatible with the 240Z's tach. Is this correct? Do I have to add the 280Z tach too.. Otherwise the 280ZX dizzy will just basically bolt on in place of the 240Z Dizzy...Right?? I have already purchased the Crane PS-40 coil. Can I go ahead and use it with the 280ZX dizzy and E12-80 option? And if so, will I need to retain the OEM ballast resistor or eliminate it? Pertronix Ignitor 2: This is a new product from Pertronix and I haven't seen any discussion on it. Have any of you guys out there used this one and do you have any comments about it or Pertronix products in general? My 73 240Z is mainly intended for moderate street performance. The rebuilt engine has the larger 260Z valves and a moderate Street cam and dual webers. OK...so here we go........ Help me to decide the best setup to use.. Many thanks...

Thanks for the input beandip. The cutoff switches are very good suggestions.....

Thanks Carl.....Great thoughts and, yes, let's all keep the issue alive and keep the faith.....

Thanks for the input hd240Z. Since I'm running dual Weber DGV carbs I did some checking around for Weber carb technical information and ran across the following web site: www.webercarbs.com They recommended using a Carter 4070 Electric fuel pump. thanks again....