Tips on Old Gasoline in Car?

[Zephyr]

So my S30 240Z project has been on hiatus for a while now. Last time I started the car was 1.5 years ago. Before that I only had about 1/8 of a tank left of 91 and I put stabilizer in. I'm going to assume the gas is bad at this point since it's been so long. So I want to start up the car again after replacing the battery. Is there anything I can do about the old gas? Is it safe to try to start up the motor with the gas in there? Should I just add new gas?

Any tips would be greatly appreciated. It's carbureted motor.

[CMW403]

I would say if its has 1/8 tank left if you filled it to the brim with premium it would be alright as long as the old stuff mixes with the new stuff.

If it was me I would drain the tank and put all new gas in cause i'm like that, I would be worried that the old stuff isn't mixing very well with the new stuff and wouldn't risk it. Not really sure what happens to gas as it ages but I'm sure it doesn't retain original quality.

[m10-power]

Run a fuel hose from the fuel return from the pressure regulator to a gerry can and run the pump until empty. You just need to jump the relay(remove it and jump power across). Best to get it out completely.

[Cos]

Originally posted by m10-power
Run a fuel hose from the fuel return from the pressure regulator to a gerry can and run the pump until empty. You just need to jump the relay(remove it and jump power across). Best to get it out completely.

Wont that burn out the pump?

[m10-power]

Originally posted by Cos


Wont that burn out the pump?

Why would it burn out the pump?

[Abeo]

I'm thinking if its a '72, then its a mechanical pump. And I wouldn't run an electric pump dry, it uses fuel to cool itself.

I would take the fuel line off where its easiest, connect a line to that which you can put in a jerry can at a point lower than the car, then siphon the rest of the tank. Look at whats coming out, too... rusty, crud, etc. To start siphoning, I'd either use a transfer pump to act as suction, or lightly pressurize the gas tank with air to force the gas through the line (slightly dangerous).

[m10-power]

Likely mechanical just assumed newer 240z.

If you ran it dry sure but as long as it's pumping fuel the pump will be fine. Just pull relay jumper when fuel stops coming out, fairly simple.

[sexualbanana]

Originally posted by CMW403
I would say if its has 1/8 tank left if you filled it to the brim with premium it would be alright as long as the old stuff mixes with the new stuff.

If it was me I would drain the tank and put all new gas in cause i'm like that, I would be worried that the old stuff isn't mixing very well with the new stuff and wouldn't risk it. Not really sure what happens to gas as it ages but I'm sure it doesn't retain original quality.

So you suggest one way for Zeph, then you choose to go a completely different avenue out of fear that the way you suggested might damage the car..... Interesting.

lol

[Darell_n]

If you put in stabilizer, drive to nearest gas station, fill tank and carry on with your day. This is what stabilizer is designed for. No need to over-complicate things.

[brucebanner]

Originally posted by Darell_n
If you put in stabilizer, drive to nearest gas station, fill tank and carry on with your day. This is what stabilizer is designed for. No need to over-complicate things.

Ding ding ding, we have a winner.

If there was anything to worry about, I would be concerned about the condition of the inside of the tank, and even that shouldn't be a concern.

[AndyL]

Almost... Yes stabilizer is good - add a bottle of seafoam just before you fill, only put in a 1/2tank... Git'r mixed in good - mostly aiming for the gum/varnish at the carb jets, and any sedimentation in the system.

[CMW403]

Originally posted by sexualbanana


So you suggest one way for Zeph, then you choose to go a completely different avenue out of fear that the way you suggested might damage the car..... Interesting.

lol

I'm not sure what you're getting at here.

Without knowing what the car means to him I gave him advice for both ends of the spectrum. He mentioned it was a build. If he bought it for 1000 and is going to rebuild the engine then who gives a fuck, fill'er up and start it. If the engine was already rebuilt and it's his baby then my advice would be to pump that shit out.

Pretty interesting eh?

[FraserB]

Kinda related.

I have a few 10L jerry cans that have been sitting for a year, I think they had stabilizer in them

Am I ok to mix one can in with 70L of midgrade already in the tank?

[tom_9109]

Methyl Hydrate. Go buy it at Canadian Tire in the paint section and put a liter or two in and fill the tank.

[revelations]

Originally posted by Zephyr
So my S30 240Z project has been on hiatus for a while now. Last time I started the car was 1.5 years ago. Before that I only had about 1/8 of a tank left of 91 and I put stabilizer in. I'm going to assume the gas is bad at this point since it's been so long. So I want to start up the car again after replacing the battery. Is there anything I can do about the old gas? Is it safe to try to start up the motor with the gas in there? Should I just add new gas?

Any tips would be greatly appreciated. It's carbureted motor.

If you ran the stabilized gas through the carbureator, then youre likely ok (esp if you drained the float bowl) .... if not, prep yourself for a possible carb rebuild.

[e31]

Although after only 1.5 years, Methyl Hydrate would probably suffice. I would normally use a siphon pump through the gas cap, but the vapor reservoir has a pretty challenging bend in it.

If you are really concerned you can easily remove the gas tank (no drain plugs on these cars). Support the bottom of the tank with a garage jack, turn loose the two turnbuckles holding the tank straps tight. You should get enough slack to unbuckle the straps and drop the tank.

[JZS_147]

lol. don't add anything, you don't need stabilizer, or any of that shit.

just drive it nicely to a gas station and fill it up.

[CLiVE]

My camaro (1987) was sitting for 4 years, and my benz (1975) for 6 years.

Checked all the fluids etc. before starting.

Added a bit of stabilizer/octane booster. Drove to the nearest station and filled them up. Drove a little rough for the first few tanks, but worked itself out.

[Zephyr]

Originally posted by revelations


If you ran the stabilized gas through the carbureator, then youre likely ok (esp if you drained the float bowl) .... if not, prep yourself for a possible carb rebuild.

I don't know anything about a carb motor, but I did run the motor as I added the stablizer.. so hopefully that will be okay

Thanks for all the info guys! Hopefully I can start her this weekend.

[revelations]

Carbs have tiny passages (think sewing needle size) for fuel to be sucked through which are very susceptible to fuel turning into a gel (which happens).

If you added fuel stab, it will simply evaporate, or stay in its present state for a while.

[Abeo]

I assume you are in Cali? I've read that people from there having issues with bad fuel (fuel going stale quick, quick to varnish, etc). I don't know if its due to CARB rules, or the climate.

In Canada, I've never had a problem with leaving fuel untreated in lawn mowers or snowblowers for ~6 months, but over a year can lead to gummed up jets in a carb. I bought a snowmobile that was blown up due to a clogged main jet, and it was sitting for about a year.

I don't know how hard those 240z carbs are to work on, but its just a matter of cleaning the gunk out and blowing all the passages clear. If it runs good when you try starting it, I wouldn't look much further into it other than throwing some seafoam in the tank.