Fuel fillup only 12 gallons?

[riversz]

Last month I finally bought a super clean 1971 240Z after wanting one for years to replace the '74 260 and '75 280 I had back in the good old 70's. I am thoroughly enjoying it but have a problem though. I cant seem to fill her up with more than maybe 11 to 12 gallons of gas at about 200 miles so I'm getting about 18 to 19 mpg. I actually ran out of gas the other day pulling into a gas station with 211 miles showing on the odometer, then it only would take 12.3 gallons to fillup......is this normal? Also when I do topoff the tank the gauge only goes 3/4 the way up but I can see the gas in the filler neck, do I maybe have a problem with the recovery tank or a kinked line somewhere or ???

Looking forward to hearing any ideas or experiences.

Thanks!

[Royce]

Well, I can think of a couple possible reasons.

1. The stock tank will hold a little less than 16 gallons. Do you have a stock tank? All the various Z tanks will hold 16 gallons or more. Most likely you do have a stock tank but after 30 years you never know. Someone may have put a racing fuel cell in it or whatever. Find a Z friend or club member and visually compare.

2. If you do have a stock tank than maybe it dented in the bottom (very common) and/or maybe the fuel pickup unit is damaged (also somewhat common). You may want to run the car close to empty then drain the tank to see how much is left in the tank. There also may be some water or other junk in the bottom that gets drawn in to the pickup when you get to the bottom of tank. Draining and flushing the tank every 5-10 years or so is a good idea.

3. The tank vents hoses could be crimped/damaged. If they are clogged, plugged, crimped this could make it so that you can not fill the tank all the way because there is no where for the air to go. Also, it can make it so that the engine cannot draw all the fuel out because air cannot get into the tank.

It may be a combination of two or three of the above. I would start with a visual inspection and then drain the tank. Then go after the hoses!

Hope it helps!

[DatsunZGuy]

With the price of a gallon of gas these days, filling my tank will double the value of my Z

[Bambikiller240]

It is also possible (In my mind probable) that the Previous Owner didn't install the vent hoses correctly, or capped off the vent hoses and thus your gas tank will suffer from trapped air which will prevent a full fill up. (the tank needs to "burp", but can't due to the missing or mis-routed vent lines) Only way to know for sure is to take out the interior panels in the back and compare the routing of the hoses to the diagrams shown in the FSM or another manual.

Good Luck

Carl

[Alfadog]

Originally posted by DatsunZGuy

With the price of a gallon of gas these days, filling my tank will double the value of my Z

Don't you dare complain! got it better than the rest of the world...

[Bambikiller240]

Originally posted by Alfadog

Don't you dare complain! got it better than the rest of the world...

Ah, the benefits of being a SUPERPOWER!!!!!!!!! LOL

Now, take that as a joke, OK??

[MikeW]

Originally posted by BambiKiller240

Ah, the benefits of being a SUPERPOWER!!!!!!!!!

Actually, the main reason that fuel is so much more expensive in other countries is the high taxes placed on the fuel. That's not exactly a bad thing if the aim is to discourage driving. Just imagine how bad London traffic would be if gas was suddenly 1/4 of the current cost.

[Bambikiller240]

Originally posted by MikeW

Just imagine how bad London traffic would be if gas was suddenly 1/4 of the current cost.

I'll let the Limeys worry about traffic in London. Just imagine , the traffic may be getting better in the Bay Area!

PS I said it was a joke!

Carl

PSS And why does a guy from Hot 'Lanta have the GG Bridge for an avatar?

[MikeW]

Originally posted by BambiKiller240

I'll let the Limeys worry about traffic in London. Just imagine , the traffic may be getting better in the Bay Area!

PS I said it was a joke!

Carl

PSS And why does a guy from Hot 'Lanta have the GG Bridge for an avatar?

I know it was a joke; I just didn't want our international friends thinking our cheap gas was somehow because we bought the oil for much less than them.

The avatar? Couldn't think of anything good but wanted something. I just went through my many vacation pics and found one that I think is cool. It's actually someone surfing under the Golden Gate bridge. You can't really see it that well in the 150x150 image, but here's the original (which you can click on for the full size view):

http://server7.aps-soft.com/Williams/SanFran/Detail-IMG_1465-JPG.html

[Bambikiller240]

Originally posted by MikeW

It's actually someone surfing under the Golden Gate bridge.

That Fella's not real bright, as that is an area frequented by Great White Sharks. One can only hope he's a Politican or a Lawyer!

[Smokey]

Originally posted by BambiKiller240

That Fella's not real bright, as that is an area frequented by Great White Sharks. One can only hope he's a Politican or a Lawyer!

Yeah, then they would be safe. Sharks don't eat their own kind.

[Bambikiller240]

Originally posted by Smokey

Yeah, then they would be safe. Sharks don't eat their own kind.

I knew someone would understand that I wasn't just "bashing", merely wishing the fella some safety!