Sometimes yes sometimes no

[sliprenoodle]

77 280z , put in a new fuel pump started right away. After a few days tried again nothing ,cranks put I cant hear the pump, a little later that day started.

Any ideas?

Troy

[SteveJ]

Yes, check the voltage at the pump when you don't think you can hear it. If it has voltage, you have junk in your trunk, er, tank. If that's the case, have the tank drained, boiled & sealed. Always have the tank full when you have the car sitting for more than a couple of days, too, to prevent condensation in the tank.

[sliprenoodle]

Thanks I'll take a look today.

[sliprenoodle]

The voltage was 9.6 does that sound about right?

[SteveJ]

That sounds low to me, unless you Canadians are using Imperial volts.

First, is your battery in good shape? Does the voltage drop a lot when you're cranking it?

Next, look at a wiring diagram. I'm not a 280Z person, so I don't know for sure how the pump is wired, but I would expect it to get its voltage through a relay. If there is a relay, it could be suffering from soft contacts. If there isn't a relay, it could be suffering from 30+ years of corrosion.

[Jeff G 78]

Like Steve said, you may have rust in the tank. If that's the case, the filter screen in the new pump would be clean to start with and then clog - not allowing it to start the next time. Pull the fuel inlet to the pump and remove the filter. If you see gunk, you have to drop and clean the tank. Been there, done that. If it's clean, look at the electrical system.

[a7dz]

Do the easy stuff first. The power at the pump should be the same as the battery.. Make sure you have power to the pump. If you have power does the pump run. I have seen several of these go bad in the last year. If it runs does it pump fuel? and at what pressure. Have you checked the fuel filter. Just because the pump is new/ rebuilt does not mean it works just that it is new.

[sliprenoodle]

Ok I'm sure its the tank, its dirty rust and stuff. were and how do I get it cleaned? Also I'm thinking I should relpace pump what do you recommend?

Thanks for all the help guys.

[Jeff G 78]

Start by removing the round inspection lid under the false floor in the hatch. It is to the right of the tire well near where the tools sit. Once you remove the cover, turn the lock ring, unplug the connector and remove the fuel sender. With the sender out, shine a flashlight down in the tank (not a trouble light!) and find out what the bottom looks like. If it's gunky or rusty, it's time to drop the tank and clean it out. Soak the fuel tank straps for a day or two in PB Blaster or other penetrant and remove the tank. The hoses can be tricky, but they will come off.

Once the tank is down, order the POR-15 fuel tank kit online from the POR15 store and follow the directions EXACTLY! It takes several days to do right, but will fix your tank for good (only if done BY THE BOOK). Here was my tank before and after. It is a messy, no-fun job, but the results will be worth it.

[sliprenoodle]

Thanks jeff I'll take a look in the tank right now.I'll let u know what I see.

[Jeff G 78]

BTW, getting photos of the inside of the tank to come out is really tough! You can either get the camera lens or light in the tank, but not both.

[sliprenoodle]

Tank is not to bad ,pump is gone. going to put in the g3 filter for now and get a new pump.

What pump do u recommend