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Topic
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00 eclipse gt v6
recently the fuel mileage has gotten horrible
any ideas why this is happening
or some insights on what to do .
already has plugs and wires changed 3k ago
ngk plugs ngk wires
also cleaned k&n filter
had oil change and new filter
i was getting close to 350 miles to full tank
i might get 250 or little more if im lucky
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Hmmm… Maybe get a scanner and check your fuel trims to see what your LTFT is…
is your air filter one of those oil impregnated ones? Those have been known to cause issues…
Also, winter blend gas is coming soon (maybe you have already got it)… with winter blend you may notice a 2 to 3 MPG loss… but that would not explain 100 mile difference…
Is your check engine light on?
If your car is not going into closed loop it will run a richer mixture and lose MPG… check this with a scan tool..Another thing is someone else driving the car…that may have a lead foot… 🙂
lastly… Maybe someone is stealing your gas…. 😛
Karl
Have you replaced the fuel filter lately or checked pressure regulator to see if its leaking fuel? If you are losing 100 miles to a tank, I’d think you’d be losing fuel somewhere possibly in one of the fuel lines. May want to inspect/smell around.
Best regards,
Ryanyes it is but i dont put the oil on the filter ,, i agree with u on the causes issues so i use it normal
i do have a scanner .
no its only me who drives it ,, i drive it normal no lead foot
i dont smell any fuel even took the back seat out and top of the tank to check it all out .
havent checked the fuel pressure regulatorbeen a while since filter replaced prob 2 year ago for new filter and pump
I have never known a fuel filter that caused bad mileage… poor performance yes, but never bad mileage.
Those oil impregnated filters have been known to cause issues with the MAF… at minimum. I would clean the MAF and revert to a paper filter and see what happens…
Karl
cant switch back to old its not stock its cold air which has been on it for a long while dont have the factory box anymore
far as cleaning MAF already did that
and also cleaned throttle bodyYou should start by looking at exhaust or fuel leak related issues. Check the EGR valve. Pull the vacuum line off the fuel pressure regulator and check for fuel, should not be fuel there. Are there any check engine codes being generated? Long Term Fuel Trim data from a scanner would be helpful.
I cover many of the things to look for with poor MPG in this article.
http://ericthecarguy.com/faq/finding-and-fixing-the-causes-of-poor-mpg
There are a lot of things to check, but I’d start by checking for any codes. They can be your most valuable clue as to what’s going on.
Please keep us updated.
ok pulled the hose off the regulator and checked it for leakage so signs
ive looked all over and no fuel leaks and also no codes
also went over it with carb spray and checked for vac leaks and found nothing everything seems solid
car runs and idles fine bare that in mind.
also here are the readings from the scanner
vacuum tests show 20psi at idle and 22 at 2000 rpm
personally with the exhaust it does have a overly rich smell but not really a bad smell or gas type smell
I would add that i did put some gumout multi-system tuneup cleaner in the fuel tank not sure if thats playing havoc and causing the issue at the moment
i have already run 2 full tanks threw the caram i missing something here or over looking an issue
if i have to replace a cat would it matter if its not CA legal since im in alabama
considering this car is CA emissions or would just a standard replacement be acceptable ?when checking the fuel pressure regulator, start the car, remove the vacuum hose and watch the regulator closely for few minutes, sometimes it takes a while to wait before it’s spraying all around.
already did that part with the regulator left it off for 5 min or so and watched it ,,
nothing leakedfuel filter is inside the tank havnt checked that as yet since the car ildes and runs pretty decent
.. theres no external filter on this one
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