ABNcherokee

The other day my fuel light came on at 1/8th of a tank, and I drove 35 miles before I filled up. 98xj took 18.8 gallons. My question is, will the xj run out of fuel while there is still fuel in the tank and if so, how much residual fuel in the tank is unusable?

So if you have run your xj completely out of fuel and then filled up, how much did the tank take? Please post XJ year and amount of fuel.

RTorrez1

I rarely let my 98 run below 1/4 tank. It is bad for the pump to run it so low. It can over heat the pump and cause it to fail prematurely and It can cause it to pull any moister/water that it in the tank into the fuel system which is also a bad thing.

sycoglitch

Why would you want to run outta gas. Tanks are 20 gals. Older tanks iirc are 16 however you can mod for 20. Usually there is an air gap so you'll only fill 18-19 gals. Light comes on for all vehicles with a 1-2 gal reserve fo people who forget to fill up. And yea, letting her run low to many times Will damage the pump do to the pump using the gas as a cooling agent.

ABNcherokee

Thank you for your comment Robert, and while I agree with you, it does not address the question.

Pelican

I don't think he wants to run out of gas, hence the questions. "Twenty gallon" tank set-ups were available on all years from '84 on.

CCKen

It is by design to have the low fuel caution light to come on at 1/8 tank.

If, when filling your gas tank at the gas station, do not override the automatic shut off feature of the gas pump inorder to get an extra pint of gas in your tank. Overfilling can cause fuel to enter the EVAP canister through the Roll Over valve on top of the tank, and contaminating the canister Charcoal pellets inside. Results may be a EVAP CEL on.

djb383

The question may not be addressed but my question is, why does that question even come up?

ABNcherokee

Djb
Knowing how much fuel in the tank is "unusable" would give you a more accurate estimate of your vehicles range. ie if the fuel pump cannot pump out the last gallon of fuel and the tank has a 20.3 gallon capacity, then you only have access to 19.3 gallons. If you know that is the case then you can make educated decisions as to how far your vehicle can travel before you have to fill up.

This isnt an exact science as multiple factors play into fuel trip length, fuel economy based on terrain being one of them, but it is better to have more data than less.

djb383

Dayum!......did I ever get schooled......talk about a data overload.

CCKen

No one said Rocket Science School would be easy.

djb383

Rocket Science School 101......take a look at the freakin' gas gauge occasionally or carry a can with u if u like to gamble. But then, what size can should one carry?

Next question will be something about the XJ operating temp as it relates to fuel residual.

CCKen

Many years ago I owned a VW 'Bug' which didn't have a fuel quantity indicator. It had a one gallon (as I recall) reserve gas tank in the trunk that was to be used when you ran out of fuel while driving. It had a lever in the cockpit that you would turn to open the reserve tank that allowed you to drive to a gas station.

Of course, as a young single punk, I was always in a drunken stupor so I never remembered to fill the reserve tank. One day I ran out of gas in the main tank and when I switched to the reserve tank it was empty. From then on I kept my reserve tank full (and had to use it several times).

In them days this was rocket science.

djb383

I remember that very same "bug"......and iirc, the water in the windshield washer squirter squirted from air pressure in the spare tire. If u used the squirter a lot, guess what else was empty (besides the squirter).

CCKen

Exactly. LOL

And, the POS heater was a heat exchanger around the exhaust. It, and the exhaust, would rot out in short order and fill the cabin with exhaust fumes.

It was so bad without heat in the winter I had to scrape the frost (from me breathing on the windshield) off the inside of the windshield with a credit card.

And the valves kept going out of adjustment and had to be readjusted every couple of hundred miles. I had a '59 while in South Carolina. One day I came up to an intersection and the engine quit. When I cranked the starter the engine sounded like a sewing macine it turned over so fast (zero compression from the valves being shot). I put it in gear and used the starter motor to turn the engine and get me through the intersection. I pushed it into a used car lot a few yards away and sold the POS for a $100 on the spot.

My '65 bug was not much better. Sold it to my Brother for $1.00.

My '99 XJ is a D**k Head but no where near as bad as those POS VW's.

djb383

I can think of one as bad, if not worse......late 50s early 60s Renault Dauphine.