Fuel Tank

[Edwin87]

Does anyone know how to identify a 22 gallon fuel tank? My truck has the 15.9 gallon and I need more capacity. It looks like there is plenty of room under the truck. My Dakota is a reg cab, shortbed, 4x4. Also, since my truck is carbureted, do I have to use a tank from a 1987 since later model Dakotas were fuel injected?

I hit a deer in the daily driver on Monday that forced the Dakota into service until I can get parts to fix the car. The Dak is only getting around 11.5-12.5 miles to the gallon. I've replaced the cap, rotor, coil, ignition module, plugs, plug wires, air filter and still get this mileage. I need more capacity and to find what's killing my mileage.

Thanks,

Ed

[Edwin87]

Well, I guess the best way to find out something is go to the junkyard with a tape measure.

The salvage yard had two 1987 Dakotas with the carb. One a long bed and the other a short and both 2WD. The tank in my 1987 is the small capacity 15.9 gal and measures about 27" long. As it turns out both junkyard trucks had tanks that measured 42". We knew we had the large 22 gallon tank. If the 42" tank will fit in the short bed 2WD, it should present no problems going into my '87.

Now to pick it up and get it installed. This 11.5 MPG is pretty bad but at least I won't have to fill up each day.

Ed

[87DakBuilder]

Is there something wrong with your carb, I have an 87 Dak, but I got around 18 mpg when I had the carbed 3.9 in mine. I also had the 22 gallon tank so maybe I wasn't getting the milage I thought. Anyways good find, and I'm sure you can install it yourself if you have a friend or a good jack. I've had my tank out of my truck at least 5 times doing repairs, and fuel line upgrades and such. It's not that hard at all. A few bolts unhook the filler hose, and lower it down with the jack. Pretty simple.


Jay

[ScatDak]

Thats what Im saying. My 88 was no power house but what it did was turn very respectful fuel economy numbers. I averaged over 25mpg on the freeway and about 19mpg in the city. I know the 88's are TBI and not carburated but your mileage should be atleast in the 20's on the freeway. Here is another thing a carb motor only has 2 things that really can go wrong with it. Fuel and Spark

BTW my 88 now gets 11mpg with the 318 thats in it.

[Edwin87]

You guys both just confirmed what I had thought. My father-in-law bought the truck about 12 years ago and said it never got great gas mileage.

I've installed new plugs, plug wires and a new ignition module in the distributor. That takes care of the spark. The truck runs pretty smooth, doesn't feel like it's bogging down or being over-revved. That's what doesn't make sense.

Could I have a restricted catalytic converter, bad O2 sensor, or something else? I haven't checked the timing yet, might be something there. What about the emissions pump?

My truck originally was built with LT195/75R15 tires and has 2:94 gears. When my father-in-law bought it used, the tires were P235/75R15. It went from 26.73" tall tires to 29.09" (that's what my data manuals at work say the height is on those tire sizes). I know that will cause a loss but not that much. I also have a A-998 3 speed auto with no overdrive.

Thanks for the responses and info. It all helps.

Ed