Gas tank size?
04-05-2013, 09:27 PM
#1
Gas tank size?
I still have yet to fix the stock gauges on the instrument cluster (only the ammeter works) and not having working gas gauge is starting to bug the hell out of me as I start taking longer trips 
I've filled up about 5 times already, so I have an idea of what I'm using, but would like to know about how much I have left
How much fuel does the stock tank hold?
I've filled up about 5 times already, so I have an idea of what I'm using, but would like to know about how much I have left
How much fuel does the stock tank hold?
04-06-2013, 03:39 AM
#2
20 gallons. If the guage doesnt work go to the in tank sending unit and check the wire it should still be connected to the sending unit even with the electric fuel pump. From there use an aligator clip on the tube where the fuel comes out clip to it and then ground the other end to frame so that there is a good ground. Turn key to on and look at guage if it should pulse and move. If it doesn't move at all guage might be bad or the guages fuse in fuse box could be burnt check it. If fuse is good there is a small metal box on the back of the instrument cluster with three wide tabs on it. You can view it under the dash and if lucky remove it. Its the voltage regulator.
You can get a new one sometimes but there is a site on the web that shows you how to take it apart and replace the insides with a electronic voltage regulator (it looks like a large transistor really its not hard to do).
If your guage still doesn't work pull the wire off the sending unit and ground it with the key off.
Go into the car and turn the key to on but be prepared to turn it to off right away. If you leave the key on for too long the guage will burn out. If the guage moves with the key on. In tank sending unit is fubared and needs replacing. If that is the case with your car I would just replace both the tank and the unit since your tank was modified.
You can get a new one sometimes but there is a site on the web that shows you how to take it apart and replace the insides with a electronic voltage regulator (it looks like a large transistor really its not hard to do).
If your guage still doesn't work pull the wire off the sending unit and ground it with the key off.
Go into the car and turn the key to on but be prepared to turn it to off right away. If you leave the key on for too long the guage will burn out. If the guage moves with the key on. In tank sending unit is fubared and needs replacing. If that is the case with your car I would just replace both the tank and the unit since your tank was modified.
04-06-2013, 04:23 PM
#5
I've bought a couple of them. Bought one for my 68 Coronet 440 I had before my R/T. And bought one for my 70 Roadrunner, they both use the same gas tank Only difference would be the size of the line coming off of it. Since the coronet 440 was a small block car. They were both supposed to be 19 gallon tanks according to the seller(didnt buy them from a small seller, bought them from a big dealer that should know the difference but this isnt always the case). Not trying to argue with you Jacilynn, this is just what I've had experience with in the past. Unless it is rated at 19 gallons to prevent overflow but will actually hold 20 or something like that?
And Snake Eater, if its the original tank there is a good chance the sending unit is so corroded up from the years it's keeping it from working. So if you find it's hooked up correct I would look at getting a new tank and sending unit. You can get a new tank on ebay for around $175.00 and a sending unit for around $50.00. If the car has sat for any amount of time through out it's life, that is probably your problem. My other 68 Coronet I had, had sat for 8 or 9 years.. the sending unit and tank both were extremely nasty. When I got the sending unit out it was so corroded it bent before it actually moved like it's supposed to. The Roadrunner sat in a shop for 10 years but was driven once every month or 2. It was almost as bad as the old coronet was.
And Snake Eater, if its the original tank there is a good chance the sending unit is so corroded up from the years it's keeping it from working. So if you find it's hooked up correct I would look at getting a new tank and sending unit. You can get a new tank on ebay for around $175.00 and a sending unit for around $50.00. If the car has sat for any amount of time through out it's life, that is probably your problem. My other 68 Coronet I had, had sat for 8 or 9 years.. the sending unit and tank both were extremely nasty. When I got the sending unit out it was so corroded it bent before it actually moved like it's supposed to. The Roadrunner sat in a shop for 10 years but was driven once every month or 2. It was almost as bad as the old coronet was.
Last edited by rcknrolfender79; 04-06-2013 at 04:26 PM.
04-06-2013, 04:49 PM
#6
I know that the resellers of aftermarket list them as 19 gallon tanks but the factory spec listed them as 20.
Then again the aftermarket lists a 5th ave gas tank as 16 when from dead empty it only holds 12 gallons max. I know as I did the one on my fifth ave from dead empty after fixing a pin hole. It is however still a factory tank on mine so maybe the aftermarket is bigger.
Then again the aftermarket lists a 5th ave gas tank as 16 when from dead empty it only holds 12 gallons max. I know as I did the one on my fifth ave from dead empty after fixing a pin hole. It is however still a factory tank on mine so maybe the aftermarket is bigger.
04-06-2013, 05:22 PM
#7
I know that the resellers of aftermarket list them as 19 gallon tanks but the factory spec listed them as 20.
Then again the aftermarket lists a 5th ave gas tank as 16 when from dead empty it only holds 12 gallons max. I know as I did the one on my fifth ave from dead empty after fixing a pin hole. It is however still a factory tank on mine so maybe the aftermarket is bigger.
Then again the aftermarket lists a 5th ave gas tank as 16 when from dead empty it only holds 12 gallons max. I know as I did the one on my fifth ave from dead empty after fixing a pin hole. It is however still a factory tank on mine so maybe the aftermarket is bigger.
Probably so if they have people calling saying their gas tanks let gas slosh out the back.. they can have the excuse "well its a 19 gallon tank, your over filling it" lol.
Last edited by rcknrolfender79; 04-06-2013 at 05:24 PM.
04-06-2013, 06:29 PM
#8
I guess I'll settle this once and for all.
After installing a new passenger side mirror, it was getting too dark to fiddle around behind the dash, so I figured I'd take jacilynn's advice and at least check the fuse box (which only took me like 20 minutes to find lol)
One fuse was indeed blown, so I headed over to VatoZone because I don't stock any glass fuses in my shelf.
On the way back, she ran out of gas at a stoplight just a block from my shop
Luckily, there's two gas stations at that intersection, and since it was already dark, I left my turn signal on because the hazards don't work, went into BP, grabbed a 2 gallon container off the shelf, topped it off and started filling up as the line of cars behind me pulled around, each yelling obscenities and flipping me the bird for wasting their time
(I guess they thought I was turning since I did have my signal on)
The stupid gas can has one of those no spill spring loaded safety filler tubes, so I was only able to get about 1 gallon in due to the awkward filler neck position :banghead:
It just happened to be enough cause she fired up and I ran the red light to get into the station as quickly as I could before she shut off
Pulled up to a pump, shut her off and got out only to find an Out of Order sign stuck on the pump (F@@@CK!!)
Started up, pulled to the next working pump and started filling.
When the pump stopped, I snapped a pic.
I figure the modified sump probably holds an extra 1/2 gallon
That being said, I'd say jacilynn's right on the money with 20 gallons (unless the station rigged the pumps to overcharge)
Anyhoo, on a lighter note, it seems that running her empty somehow loosened up the float or sumthin cause the gauge started working again
Well, sortof.....
The needle went up to 3/4 tank with the ignition on and went back to E when I shut her down.
Turned the ignition on and off a few times and the gauge is definitely working (albeit a 1/4 tank off).
So now I'm hoping the blown fuse is for my brake lights, which would be the next task at hand
After installing a new passenger side mirror, it was getting too dark to fiddle around behind the dash, so I figured I'd take jacilynn's advice and at least check the fuse box (which only took me like 20 minutes to find lol)
One fuse was indeed blown, so I headed over to VatoZone because I don't stock any glass fuses in my shelf.
On the way back, she ran out of gas at a stoplight just a block from my shop
Luckily, there's two gas stations at that intersection, and since it was already dark, I left my turn signal on because the hazards don't work, went into BP, grabbed a 2 gallon container off the shelf, topped it off and started filling up as the line of cars behind me pulled around, each yelling obscenities and flipping me the bird for wasting their time
(I guess they thought I was turning since I did have my signal on)The stupid gas can has one of those no spill spring loaded safety filler tubes, so I was only able to get about 1 gallon in due to the awkward filler neck position :banghead:
It just happened to be enough cause she fired up and I ran the red light to get into the station as quickly as I could before she shut off
Pulled up to a pump, shut her off and got out only to find an Out of Order sign stuck on the pump (F@@@CK!!)
Started up, pulled to the next working pump and started filling.
When the pump stopped, I snapped a pic.
I figure the modified sump probably holds an extra 1/2 gallon
That being said, I'd say jacilynn's right on the money with 20 gallons (unless the station rigged the pumps to overcharge)
Anyhoo, on a lighter note, it seems that running her empty somehow loosened up the float or sumthin cause the gauge started working again
Well, sortof.....
The needle went up to 3/4 tank with the ignition on and went back to E when I shut her down.
Turned the ignition on and off a few times and the gauge is definitely working (albeit a 1/4 tank off).
So now I'm hoping the blown fuse is for my brake lights, which would be the next task at hand
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rcknrolfender79 (04-06-2013)
04-06-2013, 06:47 PM
#9
Well awesome thats good to know. I bet they say its 19 to possibly keep you from over filling it and having gas slosh out, if your seals are bad. Either that or they mean that when your car's needle hits empty it's burned 19 gallons but still has a gallon to get you to the station.. maybe? Don't think I've ever driven a car that actually ran out of gas when it hit empty so that could be a method to there madness. lol Who knows what those people had in mind when they decided to say it was 19 gallons. But we know now. Thank you
04-07-2013, 08:09 AM
#10
reserve tanks started in the 70s this one wont have a reserve indent. If it suddenly started working I would say check the ground on the tank. Chances are it got wet underneath creating a ground temporarily.
04-07-2013, 08:23 PM
#11
Thing is, usually with other cars, I'd have some kind of warning like a stumble or it would stall and I'd be able to start again and at least get off the road.
Not the case with the green machine
She just died and that was that :banghead:
Fuel bowls were dry and since the pickup is at the bottom of a sump, there would be no use rocking the car back and forth to try and get some unused gas to siphon cause there simply wasn't any
Anyways, here are some shots of the gauge with the key on and off
I'll let it get down to 1/4 tank, then refill and check how much is pumped to give me an idea how far the gauge is off
opcorn:
04-07-2013, 08:57 PM
#12
My Coronet is exactly half a tank off. When you fill it up completely it stops directly on the half tank mark. I noticed driving it back from Ohio that every time I'd stop to get gas it would be right on empty and I'd have to put 10 gallons in it at every stop. Which was about every 100 miles. So I was getting about 10 mpg. Oddly enough it will go down from there all the way to empty and still have a half tank in it. I dont know if the cause for it is the gauge sticking or if the sending unit has crud on it causing it to stop there. I'll probably replace the sending unit before I pull the dash apart. Although getting the rallye cluster out is a TON easier than it is on the standard rectangle style B body clusters. But not gonna take a chance messing the gauge up before just replacing the sending unit.
04-10-2013, 04:32 PM
#13
A little update.
The next day the gauge stopped working again
Took her out for a test pass down a back road and when I hit 3rd gear hard, the needle started climbing
While I had her up on the lift to install an OEM pinion snubber, I checke dhte sender wire plug, but it seemed to be clean
Gauge has been working ever since, but still way off
A couple hours ago, she was at the 1/4 line and I filler her up with 10+ gallons, so that's a nice little reserve
Thing is, the gauge only made it half way between the 1/2 and 3/4 marks
Once I dig into the wiring this week, I'll try pulling the sending unit and see if that helps
The next day the gauge stopped working again
Took her out for a test pass down a back road and when I hit 3rd gear hard, the needle started climbing
While I had her up on the lift to install an OEM pinion snubber, I checke dhte sender wire plug, but it seemed to be clean
Gauge has been working ever since, but still way off
A couple hours ago, she was at the 1/4 line and I filler her up with 10+ gallons, so that's a nice little reserve
Thing is, the gauge only made it half way between the 1/2 and 3/4 marks
Once I dig into the wiring this week, I'll try pulling the sending unit and see if that helps
04-19-2013, 06:35 AM
#14
OK, another little update.
It seems the gauge has been hit or miss during cold morning starts, but will eventually start moving up from "E" after hitting some bumps or hard acceleration.
Thing is, it would never go to full, even with the tanks topped off, so I took Jacilynn's advice and grounded the gauge wire, turned the key and it shot up to full, so at least I know it's working as it should.
Next, I made a proper ground on the tank itself since it was painted and doesn't appear to have a ground strap
No change, so I'm about to order up a new sending unit.
Now, the tank has been modified with a rear sump and uses 1/2" lines for feed and return, so the stock tubes on the sending unit are plugged.
From what I see, there are two sending units available.
One with 5/16" tubing and one with 3/8" tubing.
Neither of which matters since they're not being used, but is there an actual difference between the floats in these units?
Reason I ask is because the 5/16" units are a little cheaper than the 3/8"
Also, another question on the vent lines.
What exactly is the theory behind running them into the trunk
It seems the gauge has been hit or miss during cold morning starts, but will eventually start moving up from "E" after hitting some bumps or hard acceleration.
Thing is, it would never go to full, even with the tanks topped off, so I took Jacilynn's advice and grounded the gauge wire, turned the key and it shot up to full, so at least I know it's working as it should.
Next, I made a proper ground on the tank itself since it was painted and doesn't appear to have a ground strap
No change, so I'm about to order up a new sending unit.
Now, the tank has been modified with a rear sump and uses 1/2" lines for feed and return, so the stock tubes on the sending unit are plugged.
From what I see, there are two sending units available.
One with 5/16" tubing and one with 3/8" tubing.
Neither of which matters since they're not being used, but is there an actual difference between the floats in these units?
Reason I ask is because the 5/16" units are a little cheaper than the 3/8"
Also, another question on the vent lines.
What exactly is the theory behind running them into the trunk
04-19-2013, 06:58 AM
#15
Mopar Lover
My 5th ave holds 18 gal at least thats as much as i ever got in her
she sat for a year or so when i went to texas for work,
when i came back and started running her the low fuel light worked half the time and now not at all.
i would like to replace the tank and relocate it over the rear axle under the rear deck, and raise the fuel door over the rear wheel well. and put a spare in the space.
she sat for a year or so when i went to texas for work,
when i came back and started running her the low fuel light worked half the time and now not at all.
i would like to replace the tank and relocate it over the rear axle under the rear deck, and raise the fuel door over the rear wheel well. and put a spare in the space.
04-19-2013, 08:10 AM
#16
aside from the tube that goes into the tank to feed fuel the units are the same float arm and all.
The unit does have a filter on it though so its actually best to run a pump off of that than the straight line into the tank that you have. You might want to go with the 3/8 one if you want to eventually put it back to a more stock performance option but its up to you.
Gort5th ave I have no idea how you got 18 gallons into that tiny tank. I have had my stock 5th tank off once to fix a pin hole leak and from bone dry it would only hold 12 gallons I measured.
The unit does have a filter on it though so its actually best to run a pump off of that than the straight line into the tank that you have. You might want to go with the 3/8 one if you want to eventually put it back to a more stock performance option but its up to you.
Gort5th ave I have no idea how you got 18 gallons into that tiny tank. I have had my stock 5th tank off once to fix a pin hole leak and from bone dry it would only hold 12 gallons I measured.
04-20-2013, 06:20 AM
#17
Mopar Lover
Are we talking about the same year 5th?
just thinking about it what kind of mid 80's v-8 would come with a small tank...
i know they were saving weight and space but, 12 gallons won't get you anywhere at 18 mpg, 216 miles? Maybe it has something to do with the region where your car was sold?
No i'm sure she holds more than 12 gal. tell you what i will top her off next time and post it. It's been a long time since i filled her to the rim.
04-20-2013, 06:32 AM
#18
Mopar Lover
I found this a Farley Diplomate
this will help us narrow it down...
Other Capacities
Item
U.S. / Metric / Imperial
Fuel, 6 cyl except wagons 18 gal / 68.2 litres / 15 gal
Fuel, 8 cyl and all wagons 19� gal / 74.0 litres / 15.4 gal
Engine Oil * 4 qt / 4 litres / 3� qt
Power Steering 2� pt / 1.2 litres / 2 pt
Rear Axle 7� 2 pt / 0.9 litres / 1� pt
Rear Axle 8� 4� pt / 2.1 litres / 3� pt
Overdrive-4 Transmission 7 pt / 3.3 litres / 5� pt
Transmission 7.7 pt / 3.6 litres / 6� pt
Txmsn w/ Torque Conv 8.6 pt / 4.1 litres / 7 pt
* Add 1 quart (� Imp Qt) with filter change.
So it's possible i got a 18 gal. tank maybe even a 19 gal. maybe it depends on the package.
this will help us narrow it down...
Other Capacities
Item
U.S. / Metric / Imperial
Fuel, 6 cyl except wagons 18 gal / 68.2 litres / 15 gal
Fuel, 8 cyl and all wagons 19� gal / 74.0 litres / 15.4 gal
Engine Oil * 4 qt / 4 litres / 3� qt
Power Steering 2� pt / 1.2 litres / 2 pt
Rear Axle 7� 2 pt / 0.9 litres / 1� pt
Rear Axle 8� 4� pt / 2.1 litres / 3� pt
Overdrive-4 Transmission 7 pt / 3.3 litres / 5� pt
Transmission 7.7 pt / 3.6 litres / 6� pt
Txmsn w/ Torque Conv 8.6 pt / 4.1 litres / 7 pt
* Add 1 quart (� Imp Qt) with filter change.
So it's possible i got a 18 gal. tank maybe even a 19 gal. maybe it depends on the package.
04-21-2013, 07:27 PM
#20
Gort5th Like I said I had the tank off my 88 fifth ave once to fix a pin hole. I emptied it bone dry to do the repair. I could only fit 12 gallons into it. Two 5 gallon jerry cans and the 3 gallon wouldn't fit all in there before it spilled. Stock tank no dents nothing. Its a 318 engine and i get 21 city 27 highway so it seems to work for me.
Note i didn't make a mistake on the jerry cans simply because I only have 2 5 gallon and a 3 gallon jerrys. Still not sure where the 3 gallon comes from though. Its so odd.
Note i didn't make a mistake on the jerry cans simply because I only have 2 5 gallon and a 3 gallon jerrys. Still not sure where the 3 gallon comes from though. Its so odd.
04-22-2013, 11:41 AM
#21
Mopar Lover
No arguments here maybe it has somthing to do with the location or epa crap..
I have never had my tank off it's actually in great shape.
But i would like to swap it for a tank over the rear axle under the deck..
a few reasons harder to steal gas by drilling a hole in it, also safer in a rear ender... "hope to God I'm Never in another Accident"! Move the balance of the car toward 50/50, and i want to raise the gas door.
I will install a full size spare in place of the tank.
I have never had my tank off it's actually in great shape.
But i would like to swap it for a tank over the rear axle under the deck..
a few reasons harder to steal gas by drilling a hole in it, also safer in a rear ender... "hope to God I'm Never in another Accident"! Move the balance of the car toward 50/50, and i want to raise the gas door.
I will install a full size spare in place of the tank.
04-22-2013, 06:31 PM
#22
O.o I have a full size spare in mine there is even a pin achor in the bottom of the well all I had to do was put the bolt in and a wing nut. 215 70 r15 all seasons is what I run on the car. Since I don't run 205 summer tires I went with the 215 to get the speedo dead on.
04-23-2013, 05:55 AM
#23
Mopar Lover
O.o I have a full size spare in mine there is even a pin achor in the bottom of the well all I had to do was put the bolt in and a wing nut. 215 70 r15 all seasons is what I run on the car. Since I don't run 205 summer tires I went with the 215 to get the speedo dead on.
with my next tire purchase i'm thinking on a set of 15x 10 inch rims and maybe a 50 series, 235...I don't much care for these 17 18 19 22 inch rims i want a lightweight rim
04-23-2013, 04:53 PM
#24
OK, a little update....
Installed the new fuel sender today
Started off by running a jumper wire and testing the new unit outside.
With the key turned, the gauge would move back and forth slowly with full range E to F
Siphoned most of the fuel out of the tank and as I removed the old unit, I immediately found the problem.
The float was filled with gas
That's why the gauge started working fine temporarily after running the tank dry, because the float would empty itself and eventually sink as it filled
Installed the new float, added 5 gallons and the gauge was still on E.
Went to the gas station and left the key on as I pumped and watched the gauge rise.
Unfortunately, it only went to 3/4 even though I pumped her full
I have a feeling the float arm doesn't have enough clearance from the top of the tank because it needed to be full tilt when I bench tested it
Anyways, at least I now have some sort of indication of how much fuel I have
Oh yeah, I also installed a new speedometer cable while I was down there...
Speedo now works, but is waaaaay too optimistic lol
90mph in a 50mph zone
I like the fact that I can bury the needle with ease, but having a Prius keep up with me while doing it was ridiculous
Installed the new fuel sender today
Started off by running a jumper wire and testing the new unit outside.
With the key turned, the gauge would move back and forth slowly with full range E to F
Siphoned most of the fuel out of the tank and as I removed the old unit, I immediately found the problem.
The float was filled with gas
That's why the gauge started working fine temporarily after running the tank dry, because the float would empty itself and eventually sink as it filled
Installed the new float, added 5 gallons and the gauge was still on E.
Went to the gas station and left the key on as I pumped and watched the gauge rise.
Unfortunately, it only went to 3/4 even though I pumped her full
I have a feeling the float arm doesn't have enough clearance from the top of the tank because it needed to be full tilt when I bench tested it
Anyways, at least I now have some sort of indication of how much fuel I have
Oh yeah, I also installed a new speedometer cable while I was down there...
Speedo now works, but is waaaaay too optimistic lol
90mph in a 50mph zone
I like the fact that I can bury the needle with ease, but having a Prius keep up with me while doing it was ridiculous
04-24-2013, 06:00 AM
#26
Mopar Lover
i was cleaning some guages a few years back and noticed on the back of the fuel gauges what appeared to be a small adjustment screw i often wondered if that would adjust the gauge/tank sending unit signal?
i think i have a few lying around i will double check and take a pic.
i think i have a few lying around i will double check and take a pic.
04-24-2013, 10:13 AM
#27
Yeah, according to a chart I found on FleaBay, I need a 37 Tooth gear (3.91 and I plan on running smaller 27.5" stock height rubber)
I actually bench tested the old one last night and the gauge went to full, but the float had to be completely vertical.
Just holding it up next to the tank and eyeballing it with the float up, it just doesn't look like it has enough room to make a full swing inside the tank
Chances are they did something to the tank as it should go all the way to full.
Just holding it up next to the tank and eyeballing it with the float up, it just doesn't look like it has enough room to make a full swing inside the tank
04-24-2013, 10:26 AM
#28
you could always tweak the arm for the float as well. Ive done it before when someone messed up an install and bent the arm. usually from new that shouldn't be the case but it wont hurt either.
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