fuel pump not sucking?

[Ophitoxaemia]

i went to check the electric pump and guess what? it is missing! the hoses come out of the tank and head on up to the front of the car.

-james

[JEFF]

James -

No pump COULD be part of the problem!:classic: ROFL

- Jeff

[Zlishous]

Ya know someone (before me) disconnected my electric fuel pump and i have been running only a manuel ever since.I have never had a problem. I asked my local mechanic if i shoud reconnect the electric and he told me it would not be that much of a difference or worth my time reconnecting everything. Now i have a 74 260, is there a difference here that i do not know about? Anyway, i have never had a problem with running only a mechanical pump. If there is some kind of performance issue i should know about? I would like to know as i will be racing (both AutoX and track) by Febraury..Thanks,

Zlish

[beandip]

The one reason for using the electric pump is then you can get rid of the "foil asbestos" crap that is around the fuel rail. The electric pump will pump fuel from the cool tank and eliminates the problem with vapor-lock in the summer . At least it really helps , the fuel rail passing over the hot exhaust manifold can heat the fuel in the line and can cause it to boil and vaporize "vapor -lock " the engine mounted pump is also heated from the engine and can add to the problem and it cant pump vapor well, so the electric pump was added to help eliminate this by bringing cool fuel forward and the extra fuel is returned to the tank . Another thing is if you ever run out of gas the electric pump will pick up the fuel right away and eliminate the need to grind away on the starter waiting for the mechanical pump to get the gas from the tank. If you add a electric pump it's best to put an inline filter before the pump to keep the crud out of the pump. I believe all the Zs were wired for a electric pump from the factory . I dont know about '70 but after that every one I have seen was.

[Ophitoxaemia]

excellent point about vapor lock!

if i want to buy a new pump, what are my cost effective options? the cheapest ive seen are about $60. do i need to get exactly 4psi?

going to a bone yard in my area is hardly worth it- they want way too much money for their junk and most of them are hard to deal with.

-james

[beandip]

The best , of cource is new from Nissan , but they are vary expensive , at least I think so , $230.00 + . What I have done is this, at the Bone yard look for a RX-7 that is NOT fuel injected I think mine is from a '79 . Not sure of the year but as long as it is from a carbed engine, and you are good to go. Mine was $15.00. Now Motor Sports sell one for $65.00 and they say that it will do the job. You can get one at the local parts store but the ones that I have seen there are so noisy , sounds like there going to rattle apart. The RX-7 pump delivers plenty of pressure and volume. I havent tested mine with a gage but if I remember right I read that they deliver from 3 to 4 lbs. and like the origional they just make a wherrring sound.

[justaZcarguy]

First of all, please correct me on this if I am wrong...

That being said, I had a similar problem with the elec. pump on my '74. The car had sat for a year or so, the gas was garbage at best and the triple Mikunis had lost their prime. Even after getting rid of all the old fuel, I could not get the lines to pressure up when starting the car. I fought this for hours thinking it was bad gas in the carbs and after some poking around, I found that the pump will not cycle with the key in the "on" position. I even ran a test light and would get nothing at the wiring to the pump. Now, here's where I may be wrong...I was told that the pump will not run unless the alternator is turning, which activates a relay and the fuel pump comes to life. This was a safety precaution from Nissan in the event that the car was in a crash or the motor quit, once the alternator stops turning, so does the fuel pump.

The reason that I am telling you this is because I wired up a good fuel pump that I had tested before I installed it and when I turned the key on to listen to the pump, I got nuthin'. Once the motor starts, my fuel pump runs without a problem. Don't chase your tail like I did thinking it was pump / wiring / me loosing my mind...

This can be a real problem if the Mikunis loose their prime, which after some disassembly and cleaning that problem stopped. I installed a push button test switch that I can press for a bit to key the fuel pump to prime 'em up before I crank it over. It has been handy. And no, this is not a switch that can be accidentally left on, you need to hold it down to complete the circut, when you let it go, the circut is broke....

I also put in a glass filter just before the fuel rail that you can see the fuel pumping thru. It's nice to see the action of your pump doing it's job, that way you KNOW that the system is getting fuel. Not only that, you can keep an eye on the cleanliness of your fuel also.

By the way, I am running the electric pump only on the '74. It seems to supply the Mikunis just fine, I have buddies that have triples on their track cars and they are pushing 9 LBS to them. I did pick up an RX7 pump and it works great, comparable in-line pumps at NAPA were around $60 to $100 and then would require a regulator also. It gets spendy quick.

Hope it goes well, keep us posted.

[Mr Camouflage]

All this talk about electric fuel pumps reminded me of a story I heard about a guy with a datsun 1200 coupe. It had an electric fuel pump fitted (i dont know why, maybe it had a newer engine fitted, but anyway) but the power supply was wired through a relay connected t the demister switch. the demister was operated via another switch located somewhere else.

So anyway, this was done to foil car theives. If the "demister" aint on, the fuel pump wouldn't work and the car woulnd get very far. And it worked too. After coming out of a movie one night the car was gone, but it didn't get very far. He found it just outside the carpark, on the side of the road with the bonnet still open. Once it had used up all the fuel in the carby it just stopped and the theives couldn't get it going again.

Which reminds me of another story.

I read a story about a guy that glued a bunch of razor blades to the back of his car stereo before fitting it. A couple of months later someone tried to steal the stereo, but never got it. But there was a lot of blood that needed cleaning up. But i wouldn't advise anyone to do that as it's probably illegal, and might just be one of those urban myth type stories.

[Ophitoxaemia]

i was reading in my haynes manual about various relays that cut power to the pump. thanks for the tip.

i will look around for an rx7 pump this week!

-james

[beandip]

James, on the rx pump be SURE that it is from a NON fuel injected car! To justaZcarguy , you need to get a shorter name, try typing your name fast on a chat lilne .Scanlon can because he types 200 words an min I hope to do 100 an hour. glad you got the black car going and good to hear your wife is doing better. Old guy

[justaZcarguy]

Yes, the wife is stumbling around like Ozzy Osbourne so I guess that you could say that she is better....

And you can just type JZ like the rest of the guys, the name is too long and had been around too long to change now...

The RX7 pump was put in the black '74 and it made it faster.

Just what it needed.

I believe the 0 - 60 is around 4.5 seconds now.

No, I am not kidding. First and second gear are a waste of my time. Can anyone donate slicks so I can hook up???????

I promise it will be a tax write-off!!!!!!

~Brian (or JZ)