04 X 4.6L Mileage Problem Help!

[freilichr]

I purchased my X with about 23K miles on it and noticed a couple of things right off. 1) the ODSII connector was hanging loose at the brake release handle 2) Mileage absolutely SUCKS on the order of about 6 MPG City.

Now this can't be right - V8 or not. I have a light touch on the accelerator and can qualify that by being a grandfather. I'm not towing a trailer, boat or dragging a concrete block. Tires are at 40lbs.

I put 20s on it and checked the speedo with my aviation GPS and it was DEAD on. That was a surprise. I expected some sandbagging built-in from the factory and expected exaggeration from the larger wheels and tires. So a couple of things may point to chip re-flashing or ???? I've also installed a K&N Cold Air Filter Kit.

Should I bring the X to the DEALER and having them re-flash back to factory settings (if that is the problem and possible)? I’m afraid to find out what that is going to cost.

What the heck is going on?

Any suggestions are WELCOMED.

Regards,

Richard

 

[GregV8]

Richard, I would definitely take it back to the dealer asap. Have them fix it as it's not a normal condition and was sold to you like this.
I also have a '04 V8 and average about 17 mpg (more city than highway).

 

[freilichr]

I might note that this was a private sale.

 

[aldive]

Have you checked the function of the O2 sensors with a scanner? How are the plugs and wires?

 

[freilichr]

No, I haven't. The scanner/flasher units sound REALLY expensive but technologically I can cope since I have a few years in high-tech uh, stuff.

Is there a hand-held that will "do-it-all" for a reasonable price?

By the way Mr. Franklin, you are my idol at 30+ MPG. WOW!

Richard

 

[tipdrill]

did you unplug your battery for 15 or so minutes after you put the k&n on?

 

[freilichr]

Yes, I unhooked the battery during the install and once thereafter. Thanks for the response!

Richard

 

[asimp]

Something is seriously wrong. I have a an 04 with the V8 and I average 18 mpg

 

[tipdrill]

hmm. are you going by the reading on the onboard computer? or are you figuring it yourself?

i dont think an onboard computer has ever been that far off, but you never know.

 

[BWilliams]

Is there a hand-held that will "do-it-all" for a reasonable price?
Richard

If you're looking for a unit that will both pull codes and reprogram your PCM, you might be interested in the Xcalibrator 2. There is at least one vendor on here that sells the device, along with custom-made progams for your truck (if you're reading, sorry that I forgot who you are!). Use the search... you should be able to find the vendor, if he doesn't chime in here.

Otherwise, if all you need to do is pull codes, you can go to Autozone and borrow a OBD-II scanner for free, with a deposit.

But.. 6 MPG?! I guess that I shouldn't ***** about my 12-14... heh.

 

[freilichr]

Thank you all for the input. I have been calculating mileage the old fashioned way, topping-off and plugging values into my iPaq/cellphone/bluetooth thingie running an oh-so-simple spreadsheet, so it isn't computer error. I considered siphoning, but the gas cap is locked and the alarm system is set to "Stun" each evening.

There is no obvious indication of a problem or "Check Engine" light. The truck runs super-smoothly and powerfully with NO hesitation or misses, by the way.

But I think that the answer, suggested by both Al and Bill, is that I have to spend some quality time with a OBSII scanner to eliminate simple things before spending to re-flash to factory specs.

I'll post my findings.

Thanks again ya'll!

Richard

 

[freilichr]

Mileage Problem Solved!!!!!

I had the Ford Dealership reflash the computer. It was done for little or no cost since there was a reflash notice sent out for this model that was not accomplished.

BUT... that did not correct the problem. I was reading that Gen I and II had a fuel flow sensor, that once replaced, magically restored mileage. So I said what the heck, and replaced it (about $80). Part number 3R3Z-9F972-AA.

Easy to replace, however, BE CAREFUL the fuel rail is highly pressurized!!!! I treated it like a good bottle of champagne, eased it out slowly and bled the presure off (away from you). The whole operation took about 7 minutes and most of that was finding the right-sized socket.

I am happy to report about 18 MPG mixed driving. Well, happy may be too strong a word.

A hearty thanks to this GREAT board!!!

Richard

 

[jah81592]

I purchased my X with about 23K miles on it and noticed a couple of things right off. 1) the ODSII connector was hanging loose at the brake release handle 2) Mileage absolutely SUCKS on the order of about 6 MPG City.

Now this can't be right - V8 or not. I have a light touch on the accelerator and can qualify that by being a grandfather. I'm not towing a trailer, boat or dragging a concrete block. Tires are at 40lbs.

I put 20s on it and checked the speedo with my aviation GPS and it was DEAD on. That was a surprise. I expected some sandbagging built-in from the factory and expected exaggeration from the larger wheels and tires. So a couple of things may point to chip re-flashing or ???? I've also installed a K&N Cold Air Filter Kit.

Should I bring the X to the DEALER and having them re-flash back to factory settings (if that is the problem and possible)? I’m afraid to find out what that is going to cost.

What the heck is going on?

Any suggestions are WELCOMED.

Regards,

Richard

Richard,
Yes there is a handheld you can datalog through to get the information needed. The SCT ExCal2 or the new ExCal3. I offer both units and have been happy with the results. If interested contact me and I will talk with you further about this.-j