Not sure what just happened, but I'd written this whole thread and it appears to have never posted, so here goes again. If the original shows up later, sorry for double-posting. Anyway, been a very long time since I've visited, but just recently bought a 2001 black/tan EB Expedition 2wd 5.4, 3.55LS, 4R100 trans, 213k miles, very good condition. Has a CAI (unknown brand) and I think a single Flowmaster that dumps right ahead of the rear axle. It's actually got a Police Interceptor badge on the tailgate, and I was told it has been a police vehicle of some sort in its past life. Was there a special police package for this truck? What would it have included? I think I found an air tank on the rear left frame rail for air ride, but the truck has conventional coil springs now. The biggest question I have is, was there ever an optional 20 gal tank on Expeditions. The manual says they came with either a 26 gal for a 4x2 or a 30 gal for a 4x4 or a 4x2 with air ride. Today I ran out of gas in my driveway, so I added a little from a lawnmower jug just to get to the gas station. At the station I put around 19.5 gal in it, filled it up. So what gives? A 20 gal tank corresponds to the 14.5mpg that it posted and the 290 miles I got on the tank. When I filled it, the computer told me like 380 miles to empty. At 14.5mpg, I'm never going to see 380 miles on a tank. It appears that the truck thinks it's got a bigger tank than it actually does. Could it have been switched? Does it have anything to do with being a "police interceptor"? I didn't think any F150-based vehicle had a 20 gal tank. My '05 Mountaineer has a 20 gal tank, but it's half the size of the Expy. Can someone please enlighten me on what I've got. Thanks in advance.

 

It's more likely you have a fuel pump that doesn't have the pickup near the bottom of the tank, or the gas tank itself is dented or partially collapsed.

 

Is there any code anywhere on the truck that shows the size tank it was built with? That would help a lot. I'm still not sure if this truck came with air ride or not either. That would tell me if it should be a 26 or a 30. Is there a way visually to tell the differences in the 2 tanks? I know it looks huge. Regarding the pickup level in the tank; are there different fuel pumps with different pickup levels, and someone could have put the wrong one in this truck? You would think that would be an easy thing to catch. And if it had been my truck and I'd have had a fuel pump replacement, and all of a sudden lost 90-100 miles per tank, I think I would have noticed. But that explanation does make sense, since yesterday when the truck ran out of gas in my driveway, it was still showing 45-50 miles to empty and the LOW FUEL light wasn't even on yet, and it was parked facing downhill. So, how hard is it to drop a tank on an Expedition? Believe it or not, when I totaled my '98 F150 many years ago, I dropped its tank to siphon it out (full tank when wrecked, at $4 per gal at the time). I kept the fuel pump assembly, thinking I might sell it later or whatever. Any chance it would work in the Expy? Thanks for any assistance.

Also, anyone else know about the "police interceptor" question? I'm just curious if it's anything more than a sticker on the tailgate. Thanks again.

 

On my door tag, under SPRINGS, I have a code 37. I can't seem to find anything online that decodes that number for me. Would that tell me if it had air-ride originally? Thanks again.

 

If it had or has air ride, when you put it in KOEO, you'll see an indicator on the cluster called "CK SUSP".

 

Can you explain KOEO to me? Sorry for not knowing. So what would happen if a truck that had a 30 gal tank had the fuel pump for a 26 gal installed? Is the 30 gal tank deeper? That would explain why the pickup didn't reach the bottom. Thanks again.

 

Key On Engine Off

 

is your driveway sloped at all? if its sloped the gas may have sloshed to one end of the tank even though its not truly empty

 

Yup, it was parked facing downhill. My trip computer was still showing 45-50 miles to empty and hadn't turned on the LOW FUEL light yet. I have no idea how many owners this truck has had, but here's what I think happened (I haven't been watching L&O:SVU for nothing). The truck came with air ride suspension from the factory (30 gal tank), but someone swapped it out for coil springs. Owner #2 needs to replace the fuel pump. Mechanic or store asks if the truck has air ride or coil springs, and the owner says coil springs. The fuel pump for a 26 gal tank is installed. Owner #2 may have never known how many miles a tank should make it, so he never missed them. Probably did run it out of gas a few times before figuring it out. I'm pretty sure the truck's computer believes it's still got its full-size tank, based on the fact that it thinks I can get 375-380 miles to a tank. I ran out of gas (at least as far as the fuel pump thought) at 290 miles. I'm sure being parked downhill didn't help matters, but I don't think that would displace 10 gal of fuel that the pump couldn't pick up. From the factory, these tanks are made to pick up fuel down to the last fractions of an inch, right? Isn't there a recessed area that the pickup sits in that always stays submerged unless you run it just bone dry? I'm just not looking forward to dropping the tank on this beast. We're wanting to use this as a family vacation vehicle, which means I'll be wanting to get every mile out of the tank I can on long trips. I hate that I seem to have 10 gallons down there that I can't use. Thanks again for any input.

Any comments on the "police interceptor" question? I'm still just curious if it's just a sticker that could be put on any vehicle or if Ford actually did something different to my truck. Thanks.

 

Definitely sounds like a logical course of events that have led your vehicle to the current situation

 

Still chewing on this problem. I did go to Autozone's page and looked up fuel pumps/senders for 2001 Expeditions. They do in fact offer 2 Delphi models, one for standard suspension and one for air suspension. Oddly enough, the standard suspension model (26 gal) is $60 more than the 30 gal air suspension model. What's still puzzling me is that, even if I've got a 30 gal tank with the pump for a 26 gal, I should be able to pull at least 26 gallon's worth, with the last 4 gallons falling below the pickup. I'm only able to use 20 gallons or thereabouts. Is there any other scenario where a pump works fine until a certain level and then can't pull the rest? I have checked the tank and it does not appear to be damaged or distorted. As I said previously, my Mountaineer has a 20 gal tank. Is there a possibility that a pump was installed for the completely wrong vehicle, but still have appeared to fit and functioned normally, just not reaching the bottom of the tank? Thanks again for everyone's help.

 

I think you are at the point where you will have to drop the tank and see exactly what's going on. Wait till it's almost empty, then park it on a LEVEL spot and run it dry. Then you can drop the tank, pull the fuel pump, take some measurements, measure how much gas is left in the tank, and measure the actual tank capacity.

 

That's not really how it works, that is assuming the fuel is stacked vertically to go from 26-30 gallons

From my understanding it's a longer tank front to back, so let's say bottom isnt accessible, but it's more volume spread over a wider/longer tank

 

Patman,
I know what you're saying. I didn't word it very well. I'm assuming that the two tanks differ mostly in depth more so than any other dimension. So then the tank volume becomes more of a function of tank depth more than anything else. The pump made for the shallower 26 gal tank should theoretically still reach a depth that equates to 26 gallons. In reality I'm sure the tanks differ a little more than that, but I'm thinking the main difference is depth.

I did confirm (almost for sure) that my truck came with factory air ride. The kick panel on the passenger side does show "air ride reset". My truck does have the 30 gallon tank, or at least did from the factory unless for some odd reason someone changed it. I was just guessing before, but I did confirm that last night. I also had stated earlier that it was parked facing downhill the day it died in my driveway like it was out of gas. I had filled the truck last night before driving the 40 miles home, and knew when I shut if off last night at home that the needle had just barely begun to drop. Well, this morning when I cranked it up, the needle had fell to almost the 3/4 level after only going 40 miles. After driving for several miles this morning the needle returned to where I'd seen it last night. All that is to say that apparently it does make a significant difference in the position the truck is parked in, especially if the pump/pickup is not exactly correct for the truck. So when I stated that it only appeared to be able to use 20 gallons, that may not have been entirely true. I'm thinking, if parked level, I probably can utilize around 26 gallons before it runs itself out. To prove that, I guess I'd have to just push it sometime (on a long trip) until it runs out, making sure I had some with me so I wouldn't be stranded. I still feel almost 100% certain that it's got the wrong pump in it, so I probably should just buy the correct pump and drop the tank someday and replace it. You know I'm looking forward to that.

Thanks again for the help.

 

The 30 gallon should be slightly taller, but quite a bit longer (front to back)

Check out my thread on my 2018 26g to 36g tank swap to get a better idea of tank dimensions
https://www.f150online.com/forums/20...llon-swap.html