w3wilkes

I think the black wire of the green / black pair at the tank is ground. I had my tank out to clean and line it and the way Datsun has the tank situated I think it's pretty much electrically isolated from the car frame/body ground. Not really any metal to metal between the gas tank and the rest of the car. So if the tabs I mentioned before on the tank are for an electric fuel pump to be mounted there it needs to have a ground wire for the pump. Same reason there's a ground wire for the fuel gauge sending unit in the tank.

Here's what I know. Bought a '73 brand new in July '73. It had mechanical pump only, no electric pump. Later that summer I took it in complaining of vapor locking. The dealer wrapped the fuel rails around the valve cover with a reflective metalized wrap. Took it back later, still vapor locking, but not as bad. The dealer installed an electric pump back at the tank. To be honest, the vapor locking was never completely cured in heavy summer traffic for the 20+ years I drove the car. I now have a early '71, manufactured December '70, I'm the 2nd owner. I believe it's a series 1 car based on things like body vents on hatch, position of ash tray, rear window defroster line direction, etc.. It has the green / black wires for a fuel pump hanging down back at the tank. Haven't hunted yet but I presume the other end to be in front of the fuse box in the front left of the console area. I plan on converting to electric fuel pump in the next month, so I'll be digging into the console to find the wires to jumper with an inertia switch to activate the wires back at the tank. Under the fuel gauge sending unit on the tank are a couple of pre-drilled tabs that I'm guessing are for mounting an electric fuel pump. Based on my car I'm betting that the Z's were plumbed from the git-go for electric fuel pumps. Side note: Found a blue taped wire w/bullet connector coming out of the harness right under the battery that is hot when the ignition switch is in the engine running position. How did Datsun know I needed that right there for my electric fan controller?

So tell me what I'm doing wrong... Here's snips of my search and the results. Doing site:classiczcars.com gas cap in Google search I only get 200+ hits on "gas cap"

Thanks for the reply. I do use the google search and it works just fine. I was just curious about the forum search because no matter what I try, including All Content in both regular and advanced search, I get zero results. It looks to me like search in the forums does not work.

Does anybody know where to get a new gas cap gasket. Mine doesn't seal very well and I can't see spending $80+ for a new gas cap!

I guess I don't know how to search the forums. It doesn't matter what I put in the search box in the upper right side I get 0 results. What am I missing?

If I put it on the accessory position and I use that position to do things like listen to the radio with the car not running I wouldn't want the fuel pump running while the car is not. If the fuel pump is in the engine running position I can turn the key to that position and let the pump charge the fuel line for a few seconds and then start it.

I would want it on the "engine running" position rather than the accessories position.

Thanks for the reply! No, no startup problems, but I would have occasional vapor lock problems in really hot weather. The car has been a garage queen for over 10 years now so I decided that since I'm going to keep it, I better get it running again. Initially I'm cleaning the fuel system front to back and doing new fuel rubber that's E85 rated so I won't have to mess with that again. Figure while I had the tank out I'd get the K&N fuel pump and go electric, never had a problem with the electric in the 73 so why not? Also getting the rebuilt SU's from MSA and putting the TBC 6 to 1 headers on. Along with that I'm going with the Champion 3 row radiator and the double electric fans on the shroud with Evans waterless cooling fluid so I'm hoping the vapor locking and heat up in traffic will be no more than a bad memory. The car has original dealer installed A/C so I'm also going to get rid of the York and go with a Sanden compressor and update the rest for R134a. The wife and I are old so we got to have A/C!

1st time poster. Just finished dropping the tank for a cleanup and hose freshen and noticed the extra pair of wires with the fuel level sending unit on my early 71. Back in the day I had a 73 Z and it did have vapor lock problems. The dealer installed an electric pump that you could hear start as soon as the ignition was turned on. I'd always let it pressurize a little before starting and it seemed to make it a little easier to start when cold. I'm thinking of just getting the electric pump, hooking it up as the Datsun dealer did so it runs when the ignition is on. Is there really any big problem with this approach? My 73 ran this way from 74 up until the car disintegrated from rust in the early 90's.