OK, I know this isn't right but I filled the 25g tank in my '88 F250 and ran out of gas after 70 miles. I don't smell gas and don't see anything leaking underneath. Any ideas as to what the heck may be going on?

Any ideas would be appreciated....thanks.

 

I doubt the tanks empty. Are you sure the gas isnt cross flowing from one tank to another?

 

What he ^ said.

Sure sounds like a cross-flow. I think '86 thru '89 had a high pressure fuel pump on the rail and one low pressure pump in each tank. May also have the dual function reservoir.

 

Not sure, but let me lay out the whole story. Just purchased the truck last month as a plow rig. The seller stated that the switch between the tanks does not work and it is set on the rear tank. I have left it there.

I filled it up 70 miles ago and it started sputtering yesterday(never even thinking it would be out of gas). Changed the fuel filter and it did not resolve the issue. Removed the lines from the fuel filter and turned on the ignition and got nothing coming out of the fuel pump. Bought a new fuel pump, stuffed 6 feet of hose or more into the tank and sucked a set of lungs full of fumes and about passed the hell out. There was no resistance when blowing on it so I pulled the hose and it was bone dry...tried the same thing on the front tank(gently) and got the same result. Put 4 gallons of gas in it and it ran like a champ to the gas station and Ifilled it up. Fuel gauge is busted.
So I'm going to do another test on the mileage and see what happens to see if the mileage was written down wrong(brother was driving it when it was first recorded).

The end.

 

if this is the story then why are you asking, sounds to me like just forgetting a number or something, or someone stole your gas LOL

 

You left out some very key points in your description. What motor/transmission/axle gears & tire size are you running?

It is a plow truck, is the plow on it & in use?

What type of driving are you doing? Highway speeds or puttering around on the farm?

How much idling time does the truck get?

Locked in 4x4?

If its a 460/C6 or T19 with 4.10's & 33's, the plow on it, plowing & driving highway speeds, idling for an hour every morning before you get in it so your heater is nice & warm, and it stays locked in 4x4, I'd say your DANG lucky for 3mpg.

On the other hand, if its got a 460/ZF5 with 3.55's & 245/70's, you're running no plow, 2wd, no warm up time & you're doing a mix of city & freeway, then I'd say you've got a reason to be alarmed.

 

After some more research I think you are right on. 460, plowing(in 4wd) and highway driving(2wd), not a whole lot of intentional idling but I think that's what the deal is. My brother talked to a guy that had a plow business and was running a few Dodge Cummins and he said he would get 4mpg on his plow rigs.

I guess it just shocked me due to my inexperience. Thanks a lot for helping bring the ugly truth to light!

 

I could be off base here but when I first got my '56 it still had the gas tank in the cab. I kept running out of gas after a day or two of driving. it took a little trouble shooting but I figured out that the tank feed tube had rusted a hole about 2/3 up the tube. once it hit the hole it sucked air instead of fuel. for a temp fix I drilled a hole and ran some tubing from the parts store next to the old tube and JB welded it place. that temp fix lasted until I replaced the tank two years later. like I said I could be way off. I not that familiar with your truck but it possible you could have something like that going on. on another note, I had a jeep one time going through a tank a day. I didn't smell gas but one day I stopped at my dads house with a friend He opened the hood and almost immediately saw a stream of fuel shooting out onto an exhaust manifold. that last thing I would want to mention is check your fuel line placement. it could be that once your engine gets hot it could have a fuel line too close to the exhaust or maybe the oil pan, and cooking off inside causing it die like ran out of gas. those are a few of my personal experiences.

 

Recalculate your mileage using a smaller tank...yours isn't 25 gallons. The front tank is something like 19.6 and the rear is something like 16.8 gallons, not the 25 gallons you stated.

I have a feeling that some of your problems lie there...

 

One thing you could do is start the truck and let it warm up for about 5 minutes, letting it idle in the driveway. Then walk to the tailpipe, and sniff it. Do you smell gasoline?

Because maybe, it's just running pig rich.

Assuming your 88 is EFI, sometimes when the o2 sensor kaput goes the computer compensates by using way to much fuel, and a lot of that goes out the tailpipe.

When that happened on my 93, the mileage went into the toilet and I could smell the gas vapor really well.

Also, if you live in a cold, oxygenated gasoline state, that will hurt mileage too but not that bad.

 

I'm going to look into this, we relized that the tank may not be that big after my original post when we filled it up.

I'll check this today too...

 

what about leaking injector ! is there fuel in your oil ?

 

you can't measure fuel economy while plowing in miles per gallon.
you need to track economy while plowing,as gallons per hour.
see,your not "going anywhere" when working the engine like this.
so all the stop and go,and going nowhere in reverse,all uses lots of gas,but it wont show up on the odo as miles.
if you want to track the economy when plowing,then you need to measure it in time,not miles.this way you can figure out how much overhead (in fuel alone that is) it takes to plow a certain lot,and how much fuel is required to get there and back,or to the next lot/drive.

your pushing snow which uses extra fuel.
your locked in 4wd which uses extra fuel.
your reversing and idling which uses extra fuel,going uncounted on the odo as "miles".
your carting extra weight which uses extra fuel.
your pushing a wall of air,which uses extra fuel.
your starting and stopping rapidly,which uses extra fuel.
everything about plowing uses loads and loads of extra fuel,that a truck driven down the street at a even pace doesn't.

the engines energy is going into "moving snow" not just "driving".

 

Good post ^^^.

I drive a '91 International dump truck (not sure which engine, but it's a 6-cyl turbodiesel) with a 10'8" Boss Power-V blade (8'2" with 22" of extensions) for a friend of mine who owns a landscaping company. I don't keep track of the fuel usage, but offhand, I probably go through 25 gallons of diesel in 12 hours of plowing or so. I doubt I drive more than 40-50 miles. Between lots, I'm dragging a tandem-axle trailer with a tracked Bobcat T190 on it (with a 10' plowbox and sometimes a standard skidsteer bucket, too).

You haven't plowed until you've plowed a large, busy Walmart lot in a big truck like that...wow, people are dumb.

Jason