fuel pump relays
 

i recently replaced my fuel pump, to find out that it isn't getting any power. i've tested the relays, they all work. It seems that from relay #1 (the one above the fuse box), the wire doesnt have any power. I've traced it, it looks nice green. I just couldnt figure it out. I haven't looked at all the wiring right next to the relay, as its in one of the most impossible places to get to (and my haynes man. says its located here for convenient access, bah). Before i take my whole dash apart, does anyone have any ideas?

right now i have it wired to my ignition switch, to power it when the car is in the "on" position.

Re: fuel pump relays
 

Saw your other post, too. I've had *exactly* those problems before, and you can find it in the wiring schematic in the FSM. Here's what you'll see: There's a "feature" in the alternator that cuts power to the relay which cuts power to the fuel pump if the alternator for some reason stops putting out power (e.g. you ran into a telephone pole and the motor stopped). I suppose this keeps from spraying gas all over the engine compartment in case of an accident. What really happens though is that when your alternator starts to die, it's that little "safety" circuit that starts cutting power to your fuel pump relay. The reason it starts and runs at first is that the whole safety garbage gets bypassed when the key is in the "start" position. Fuel pressure is built in cranking and there's enough to run the car for a few seconds before it drops below what's needed by the injectors. Replace the alternator and all should be well. Good luck!
Dave

Re: fuel pump relays
 

thanks!!! that helps alot. No i can not have a wire running across the car to the ignition wires lol. but right now i am replacing EVERYTHING in the fuel system. well, i lied. i'm not replacing the injectors. im replacing the filters, pump (which i already did), tank, and the fuel lines. the tank was full of rust.

does anyone know where i can get a fuel tank? i can look at my parts car, because it isnt so rusty, but if that one isnt so good, i don't know where to go as my local shops can't get one for me.

Re: fuel pump relays
 

If it helps, there is a fuel pump relay in the dash. If you take out the glovebox, on the right side there are two relays. One is for the fuel pump. This is on my 82 280zx. Might be the same for 79-83

http://www.zipcon.net/bleach/pages/zcar/zlogo.jpg

Re: fuel pump relays
 

All the usual spots like Motorsport and Victoria's British, etc. have tanks, but they are really spendy. One option is to get either of your tanks (preferably the less rusty one) reconditioned and sealed. Various shops can do that for you. What basically happens is a cleaning/rust treatment type compound gets put in there and swirled around to try to get things as clean as possible. That gets rinsed out with a solvent, and then a sealant gets put in the tank and sloshed around until it coats the whole inside of the tank. It's a really thick liquid that basically coats the inside of the tank and then solidifies into a plastic-like substance. There are a variety of compounds used for that (obviously all are supposed to be inert to gasoline). The thing is, a bad shop using low-grade treatment chemicals may not really do your tank any good. So, you'll want to ask around to the fellow car nuts in your area and see if they know any good shops that'll "slosh" gas tanks. In the States and Canada it's usually pretty cheap, like $30 or so. If this meets your needs, it saves major cash for other projects, like a new cam, or a new exhaust system, or coilovers, or... :)
Just be glad you caught the rust before enough got through and clogged your injectors 100 miles from home!
Dave

Re: fuel pump relays
 

cool thanks. thats what one of my friends told me. just go get it cleaned at a radiator shop. i know a good radiator shop too. woo hoo. now if i werent grounded i could go and do these things

Re: fuel pump relays
 

I thought I saw something about electric fuel pumps not working until the engine gets above 600 rpm's. Check it with the engine running and see if that helps.
I might have a good gas tank for sale. I will check it out this weekend if you still need one.

Britt

Re: fuel pump relays
 

Well, I got grounded until after x-mas. So I can't check until after then. But I'll let you know then, and thanks for the info.

o/---\o <---my car