mpg problems
Thread Starter
|
Senior User
Joined: Apr 2013
Posts: 235
Likes: 0
From: Corpus Christi, Texas
mpg problems
I understand that these trucks where never meant to get great gas mileage but this is ridiculous for an efi...im getting about 7.5- 8 miles to the gallon, its a 97 f-250 single cab 351w sd with an e40d transmission 3.55 rear ..now its obd 1 and I read somewhere that those only have 1 o2 sensor is that correct? I'm thinking about replacing that and hoping that works to boost it ( I'd be happy with 12 -13mpg if I could get it, I'm not expecting 17) if anybody has any ideas please let me know. (already replaced map sensor and plugs)
Thread Starter
|
Senior User
Joined: Apr 2013
Posts: 235
Likes: 0
From: Corpus Christi, Texas
ok ill do that, how far would you recommend advancing it? what about the o2 sensors the PO trashed the truck and ive had to rebuild it from the ground up, i just got it running (not fun considering it looks like it was sat in salt water for two weeks) the exhaust consists of cut off glass packs and no cats so if there are cutoff pig tails for two more o2 sensors then i haven't found them, it would save me alot of time if i knew there was just one.
Logistics Pro
Joined: Mar 2012
Posts: 3,507
Likes: 121
From: Oregon
There is only one. I would replace it, but with a Motorcraft one, not store brand. As for advancing, 12-13 BTDC degrees usually yields benefits with the plugs gapped at .055 inches. However, use less if the truck begins to ping under load.
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Do both tanks work?
There is a common fuel transfer problem with these dual tank trucks where fuel is returned to the other tank while you drive which will make fuel consumption look absolutely terrible. Even if the pump in one tank is dead this can still happen, you probably won't notice unless you start to small raw gas when you stop because it's overflowing out the filler tube or leaking from the evaporative collection system.
Also be sure to pull the codes, it's not hard to do will go a long way to eliminating guess work.
There is a common fuel transfer problem with these dual tank trucks where fuel is returned to the other tank while you drive which will make fuel consumption look absolutely terrible. Even if the pump in one tank is dead this can still happen, you probably won't notice unless you start to small raw gas when you stop because it's overflowing out the filler tube or leaking from the evaporative collection system.
Also be sure to pull the codes, it's not hard to do will go a long way to eliminating guess work.
Trending Topics
Thread Starter
|
Senior User
Joined: Apr 2013
Posts: 235
Likes: 0
From: Corpus Christi, Texas
thats an excellent point I had forgotten about that problem, my best friends wife's truck does that... my front tank currently doesn't work i filled up and then found out that when i flick the switch my motor stops getting fuel and dies..but I will loosen the filler neck just a little and see if the neck gets wet. Tank is full so it shouldn't take but a bit of driving to see if something is wrong in there. I do smell what might be gas (..maybe un-burnt fuel?) every once in a while but its usually on the passenger side (where the exhausts dump out).. there is a check engine light on intermittently it turns on and off everyonce in a while ...but i don't remember what it was for..I'll pull it again and post it
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread Starter
|
Senior User
Joined: Apr 2013
Posts: 235
Likes: 0
From: Corpus Christi, Texas
shes a SD or Speed density so I think there is only one, on MAF I think there is a maximum of three the up streams located right before the cats and then one downstream near the tail.. I think thats how its set up, don't quote me on it. On mine I just have one near the tail..
Thread Starter
|
Senior User
Joined: Apr 2013
Posts: 235
Likes: 0
From: Corpus Christi, Texas
i drove it this morning to school I didn't notice anything that smelled like raw fuel nor was the neck wet but ill keep checking on it, I think my problem might be from multiple causes and not just any one thing.
Lead Driver
Joined: Feb 2013
Posts: 5,006
Likes: 72
From: Roseville, MN
You advance the timing to get the best mileage you can out of the engine. Advance it to where it pings lightlty under load, then back it off just enough to get rid of the ping. That'll give you the best results.
Thread Starter
|
Senior User
Joined: Apr 2013
Posts: 235
Likes: 0
From: Corpus Christi, Texas
okay cool ill do that..i smelled raw gas today under my truck when i got to school, im assuming its the problem Conanski reminded me of with the fuel tanks..i have yet to get that front tank working due to me being busy i'll check to see if it has power today if it does then ill pull the bed of this weekend or something..s
Some details on my front tank..when i hit the selector switch my gas gauge goes to empty and my truck dies...im thinking either the pump is out or its not getting power, anybody have any guesses?
Some details on my front tank..when i hit the selector switch my gas gauge goes to empty and my truck dies...im thinking either the pump is out or its not getting power, anybody have any guesses?