Electric fuel pump

[tanny]

I have a 73 240 z and the first time I attempted to start the engine after a rebuild(actually first time ever since I purchased it) I noticed that the electric fuel pump runs continuously when the ignition is on and the engine is not running. Is this normal? Is there no pressure cutoff switch? The pump is pumping gas when I test it and there is no return line to recirculate the gas. Thanks, Victor.

[beandip]

There should be a return line that is running with the fuel rail and it ends at the front end of the engine by the valve cover. The end of the metal line is closed with a small hole that allows pressure to escape , and fuel to return to the tank thru a rubber hose connected to the return line. Now as for the pump runing , my pump is the same as yours and I am working on a remady , If you come up with a pressure switch from the oil pressure droping , or a elect. cut off if the engine stops . Pass on the info. and I will do the same. gary

[tanny]

Thanks for the info, but I have three webers(forgot to mention), and there are no other fuel lines coming to the carbs. I do see a metal line that parallels the metal fuel pump line and it ends at the front of the passenger side wheel well. It does have about a one foot rubber hose on the end that is open and hanging free. I had assumed this was some sort of an evaporative line for the gas tank(smog stuff). Would this be the line you're talking about and does this just allow some pressure release(gas vapor) or is it supposed to allow the actual liquid gas to recirculate back to the tank when the carb bowls are full? Sorry to sound so stupid, but this z is my first and it was modified more than I would have liked, so there are plenty of doo-dads missing and others left hanging, etc, etc. I guess I can console myself that at least it has almost no rust. Got it started for the first time(first time in twenty-one years) yesterday after I rebuilt it, but it appears that the front two webers idling circuits are not funtioning(or functioning very little), so I have even more work ahead.

[beandip]

On the passanger side there should be two metal lines coming out of the trans tunnel next to the starter and they travel along the top of the frame rail. One is about 1/4" and the other about 1/8 " in dia. . The largest one is the delivery fuel line and the smaller one the return . Both metal lines terminate right near the alternator and the supply line then is connected to a fuel filter via a neoprine hose and in my case from the filter to the fuel rail, I am running electric pump only. The stock fuel rail is a loop that is the larger size and it runs along the valve cover on the driver's side and has outlets to the carbs . At the rear of the engine it makes a 90deg. bend and follows the delivery line back around the front and connects via a neoprine line to the small metal return line. When the fuel rail makes the 90 deg bend it is reduced in size, at the end of this line where it becomes neoprine , is where it is restricted down to restrict flow and maintain pressure. I hope this helps. Gary

[tanny]

Thanks for the info. Good to know what the line was for. Hopefully not having it plumbed to the Webers won't increase my chances for vapor lock. I think I'll just seal that return line off. I'm not sure if this car ever had any vapor locking problems, but I guess I'll find out soon enough.

[beandip]

You dident include the location where you live , but in the summer heat and the fuel rail traveling right above the exhost manifold , dont count on it not having a vapor lock problem. I am running elect. only and have driven in 110+ this last summer in eastern Or. and some in traffic and had on problem . One thing the engine was running at normal temp also. If you live in a warm climate and need to be at idle in traffic often it may be wise to at least insulate the rail.

[tanny]

With three webers, I don't really have a fuel rail, but the rubber fuel line runs directly in front of the valve cover and then runs along the air cleaner side of each carb. If I have a problem next summer, I'll try insulating. Doesn't get that hot here in SW Colorado, but I'm wondering if the headers will heat up the underside of the carbs excessively because there is no heat shield. If that happens, I guess I'll need to fabricate one. Right now I'm anxious to get the brakes bled so I can finally see how this thing drives and to see if there are any unexpected problems from the tranny on back. Hope not. Thanks, Victor.

[Phacade]

Well on my '73 here is what I did. I took off the manual pump and got a Purolater pump in the blue package from Pep Boys and mounted it in the rear. Holes matched exactly. A few rubber grommits insured that it would not vibrate. I then wired it up. After that I wired up a ful cutoff switch and installed it. Then I had the means to turn off the pump and also added security.