rx7no8

are the gas tanks in 84's the same as 82's

81gsl12a

iTrader: (1)

NO... but if you are asking if it will work yes... the 84-85 tank is better woot the sending unit is removeable 83 and back it was not..... errr the suck

82transam

iTrader: (18)

No, but you can interchange them if you are talking 12a cars, the GSL-SE tank is slightly different.

82transam

iTrader: (18)

haha, damn you beat me to it.

Rx-7Doctor

iTrader: (13)

All sender units are replaceable in all year RX-7's.

82transam

iTrader: (18)

I think he was referring to the feed/return line assembly being replacable on the 84/5 tanks where as the lines are brazed to the tank on the earlier ones....

Rx-7Doctor

iTrader: (13)

The replacement part numbers for the 12a and 13b fuel tanks for 84-85 are the same. I don't know if Mazda originally supplied them that way in the beginning or they changed when they did replacement tanks.

81gsl12a

iTrader: (1)

sorry for the mis info....well 82transam knew what i ment.... most tanks the sending unit and feed tubes are all in 1.... but that is what i ment was the feed tubes are not brazed to the tank

82transam

iTrader: (18)

Really? odd, guess they did that to simplfy things in the replacement parts warehouses. Most of my work has been on 83's, so I've never seen the inside of a 84/5 tank, I wonder if the original 12a ones were the same as the SE tanks with the slosh baffle in there....

Rx-7Doctor

iTrader: (13)

One way to find out if the part #'s were different in the beginning is look at the original parts fishce.

trochoid

iTrader: (6)

I have a thread in the archives that shows the difference between the 12A and SE S3 tanks. The tanks themselves are the same, with the exception of the sump cup on the SE tanks. The fuel line units are different, but will fit either tank.


No they are not, they are seperate. It wasn't until the 2nd gens that the fuel lines and fuel sender were combined into a single unit. Even then, the vent line is seperate on the FC tanks, where it's part of the removabe unit on the S3s. Strike 2 on misinformation, lol.

mazdaverx713b

iTrader: (91)

basically, to put it very simple, the top of the tank is different and if you were to try and put an earlier(81-83) tank into a later car(84-85), the tank would not fit due to the shape of the top of tha tank and the tank will hit on the spare tire well.

trochoid

iTrader: (6)

I'm not sure if this is true. The SA tanks are smaller, the S2 and S3's have a larger capacity, but this is mostly due to going from a full sized spare to the space saver. I'm not sure what year this change was made, but I believe it was 81. If the change was made in 81, I believe all of the 81-85 tanks should be the same size and configuration. My 82 and 85 FSMs show both tanks having the same fuel capacity and the same space saver spare. I have yet to add the 81 FSM to the collection.

81gsl12a

iTrader: (1)

lol i was talking about gastanks in everything else jeeps/chevy/ford/ect ect....

82transam

iTrader: (18)

I believe any 81-85 tank will fit any 81-85 car, the spare tire well and trunk floor pan design should be identical in all years, so the shape of the tank should be as well. there were only a few minor changes to the body in 84/5 and none of them were in the trunk area....

Rx-7Doctor

iTrader: (13)

Now you are really back-pedaling.LOL.

Perhaps you forgot that this is a RX-7 Forum.

mazdaverx713b

iTrader: (91)

the tanks are definatly different. i tried a tank out of an 81 and attempted to install it in an 85 GSL that i had. the feed and return lines have a different spacing. they will hit on the spare tire well. the tanks are the same capacity, yes but because the lines are fixed on an 81-83 tank, they make the tank different. mazda even lists a different part number for the tank for an 81-83 and an 84-85(SE included). if i have time tomorrow i'll snap a pic of an 81-83 tank next to an 84-85 tank.

trochoid

iTrader: (6)

Pics are the best way to settle the question. All of the 1st gens I've had have been S3s except one that was parted. I didn't pay much attention to the tank for differences.

74RX4

iTrader: (10)

Here's some pictures. These 2 tanks would not interchange. They are a different shape. I'll be pulling the tank from an 85 GS soon. I'll be interested to see the if it is like the GSLSE.

http://intertron.com/ron/tank.html

mazdaverx713b

iTrader: (91)

the later tanks are thinner on top where the spare tire well is and have a larger surface for the spare tire well. it was last summer when i tried an 81 tank in my 85 GSL and it was a tad hard to remember the exact reason why the tank wouldn't bolt up. thanks for the pics 74RX4!

DublyDurty

Hey guys,

You've just added to my confusion. I have an 83 GS and was planning to replace the tank with one I recently purchased (see picture below). The tank on my car has a fuel drain plug underneath but the replacement tank doesn't. Then I look in the Haynes and on page 253 Section 6.3 it says "The fuel tank on 1983 and later models incorporated a drain plug,.."

And after looking at the pictures provided by 74RX4, my replacement doesn't look like either one. By that I mean, my replacement has an additional tube coming out of the top that is connected to a rotating white plastic insert (look right in the middle of the picture below).

I haven't removed my old tank yet so here are my questions;

1. Before I remove my old tank, will this replacement tank absolutely fit?

2. Since the replacement doesn't have a drain plug, is that an indication that it's for an earlier model and will not fit?

3. What's that additional tube connected to the rotating white plastic insert in the middle of the picture?

Thanks,

DD

mazdaverx713b

iTrader: (91)

what are the dates on the fuel lines on the new tank? that wil help identify the year of the tank. i've never seen a tank with that plastic thing. it may be something extra for a california emissions package but to be certain, i do not know. maybe its an extra check and cut valve. if you have an 83 and this tank is from an 81 82 or 83, i do think it will fit. i would venture to say that from the info gathered here and my experience with the tanks that an 81-83 tank is the same. i checked mazdatrix's websit and it verifys the 81-83 tanks are the same and the 84-85 tanks are the same.

DublyDurty

mazdaverx713b,

Fascinating stuff. I didn't notice that the hoses had dates until you brought that to my attention! Thanks!

The dates are 81/01/22 on the tank air vent hose and 81/01/26 on the "mystery plastic rotating insert" hose. Does that help?



Me and Mr. Peabody set the "Way-back" machine to "early archives" and I found some posts by trochoid (before he knew how to upload pictures (heh heh) explaining differences in gas tanks, and others by DAVIDGRIMES (that had the same tank in a picture) but I still don't feel I have a definitive answer to my 3 questions above.

I "gas" I am rather dense sometimes.

"Tanks" for any help,

DD

mazdaverx713b

iTrader: (91)

based on the hose dates, i would say that the tank you have is from an 82.

Rx-7Doctor

iTrader: (13)

The tank is from a 81/ I pulled it and sold it to him. The 81-83 tanks interchange. This is from a Ca car.