Still avg 5mpg after maintenance?? Wtf is going on?

bottled2v · Mar 7, 2012

eddy's got a point as well, my grommet was leaking on mine as well and whenever it was over half tank it would almost pour out whenever i turned left.

mustanginky · Mar 7, 2012

if it's getting that bad fuel economy there would be extreme evidence of it running rich, exhaust smell, black exhaust, running POORLY. my guess is on the fuel tank gasket. just a guess but i'd have to say that's probably what it is, or a busted fuel line.

cschoening09 · Mar 7, 2012

im sure you would obviously smell gas if its leaking...but o2 sensors would be worth the 50 bucks a piece i bet if there are a decent amount of miles on the car anyway its not a bad idea.

yamanx · Mar 7, 2012

Sounds like gas tank grommet. It is allowing the fuel to evaporate before it is used since the car is not showing signs of running rich.

cschoening09 · Mar 7, 2012

nothing against yaman...valid suggestion. but i cant see that much gas evaporating in half hour to an hour when he states the fuel is gone

nkausch · Mar 7, 2012

If you want to test the o2's take them out and look at them. If there all black then you'll need new ones.

Shaun13GT/CS · Mar 7, 2012

cschoening09 said:
nothing against yaman...valid suggestion. but i cant see that much gas evaporating in half hour to an hour when he states the fuel is gone

I agree! The gromet is also near the top of the tan, so unless hes banging hard right turns constantly, it wont leak that much.

View your short term fuel trims. Should be around -5 to +5. I believe anything lower the -5 is rich, and higher then +5 is lean....I believe I could be wrong, might be the opposite.

Pull the plugs too, take a picture and post them. Close ups on the electrode to see if its running rich.

02GT89 · Mar 7, 2012

well I will have to do this in a couple of days to test the o2's unless they're really easy to get out btw the car has 116k miles on it... and what is a gas tank gromet? I am willing to try anything.

also suggestions on what brand to get im seeing bosch , ntk , ect.

Woodman · Mar 7, 2012

Having had a fuel tank leak, you WILL smell raw gas if it's leaking. So while a possibility, if you're not smelling gas, it's doubtful.

Are your plugs gapped properly? What condition are your COP's in? Any idling issues or running odd when under load?

As everyone else has said, your O2 sensors are the most likely culprit. Also, have you cleaned your MAF? You haven't done a tune up on a Ford 4.6 until you've cleaned the MAF.

Let us know what you find out.

02GT89 · Mar 7, 2012

the plugs were some kind of special ones that didn't need gapped or some crap so i was told I didnt put them on, but was told the cops looked great when the job was done , no idling issues at all , no smell of burning or leaking fuel , no puddles , the maf has been cleaned within the last 6 months.

so i suppose only thing left would be the 02's even if its not throwing a code?? keep in mind I had an o/r H pipe that was throwing codes on my car for a year running really rich, I bet the diodes on them are fried.

are the 02's extremely easy to pull out and check????? what would be required? is it something i can do over the course and an HR or less?

Shaun13GT/CS · Mar 7, 2012

COPs can look great but not function correctly.

02GT89 · Mar 7, 2012

well seeing how cops are expensive as hell I think I will try new O2 sensors first, but foremost someone please tell me how hard it is to just pull 1 o2 sensor out to see if their bad?

eddy21x · Mar 7, 2012

not hard at all just get the stocket to make life easier

nkausch · Mar 7, 2012

Depends where they are on my 94 there easy to get to even with just a normal wrench.

Either way it's never taken me more than 10 minutes to check an o2 on any car.

Jiffy · Mar 7, 2012

If it runs nicely with suitable power and you're only using a sniff of throttle, it's unlikely to be COP's. To check if it's running too rich, follow it in another car and get someone to give your car a soft drive and a hard drive, if you see clouds of black smoke then it's burning that fuel. If you see nothing, it's leaking that fuel...

Woodman · Mar 7, 2012

02GT89 said:
the plugs were some kind of special ones that didn't need gapped or some crap so i was told I didnt put them on, but was told the cops looked great when the job was done , no idling issues at all , no smell of burning or leaking fuel , no puddles , the maf has been cleaned within the last 6 months.

so i suppose only thing left would be the 02's even if its not throwing a code?? keep in mind I had an o/r H pipe that was throwing codes on my car for a year running really rich, I bet the diodes on them are fried.

are the 02's extremely easy to pull out and check????? what would be required? is it something i can do over the course and an HR or less?

Anyone who tells you plugs don't need gapped is either lying or an idiot. Yes, I understand some plugs come gapped from the factory, but a gap gauge is $2, just check them and make sure they're right. If they're not right, they will cause issues, and compound any other problems you may be having?

eddy21x · Mar 7, 2012

if a cop werent firing wouldnt it make it rich?

Woodman · Mar 7, 2012

eddy21x said:
if a cop werent firing wouldnt it make it rich?

It should... I had one not firing and you could smell the raw gas.

04 BEAST · Mar 7, 2012

I've got same fuel issues and i've changed O2's,fuel filter,gromet,plugs cleaned air filter and replaced fuel pump still getting crappy gas mileage!!

eddy21x · Mar 7, 2012

i know if a cop aint firing that gasoline aint igniting

I wouldnt be so quick to dissmis the cop

Still avg 5mpg after maintenance?? Wtf is going on?

bottled2v

mustanginky

cschoening09

yamanx

cschoening09

nkausch

Shaun13GT/CS

02GT89

Woodman

02GT89

Shaun13GT/CS

02GT89

eddy21x

nkausch

Jiffy

Woodman

eddy21x

Woodman

04 BEAST

eddy21x

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