10mpg!

[laxmax327]

ok, i cant stand this anymore, im down there w/ my buddy's monte carlo. and that things running mid 11's. no reason for me to get that shit.

maf? what should you use to clean the maf? or might it need to be replaced?

ect? how do you know if thats it or do you just need to guess and replace it. the temp gauge does seem to work properly, but that wouldnt really matter right?

wires? I think the wires are fine, they look good and cant see any arching.

i suppose i can change the plugs just for ***** and giggles.

already did fuel filter and o2's.
actually, i think its something to do w/ the o2's. when i first bought the car and noticed the horrendous mpg i did them first. but when i went to do it, low and behold, one of them wasnt even connected! so i was excited that this would definately fix it, but no... not one mpg better. so dunno whats up there, going from one disconnected o2 to 2 brand new ones, should have at least helped... but nothing! im sure i fixed the wires fine. i also had a broken front motor mount for a while which did some damage ( good by abs ) and i would assume thats what killed the o2 wires, but as far as i can tell they all look good now. how can i tell if the computer is actually geting a signal from them or what? and yes i do have a slight draging brake issue, but that cant make it this horrible.

thanks for taking the time to read my rant, any advise would be greatly appreciated as i cant afford this anymore

edit: o yea, forgot to mention, car runs excellent, very fast and responsive now. pulls very hard up till 7k ( even over a few times ) but 1 thing i recently noticed, but its barely there and you have to be trying to notice it. when cruising at steady throttle sometimes you can feel it randomly pull a bit, then slow down. but no passengers have ever noticed it, and i barely can, only now cause i pay attention for it. its like you give it the slightest bit more gas, but im sure im not.

 

[ohfosho]

do you have an auto or stick tranny? auto's, from what i hear eat up a lil more than the sticks do. you can give the car a tune up, and clean the intake manifold right out...it gets really dirty with no pcv valve inline. clean your throttlebody, run injector cleaner through, run some seafoam in your gas tank, and run it though an engine vacuum line to clean the thing right out...and an oil change of course!

 

[laxmax327]

its an mtx, i think im goin to pull the intake, clean it up and while its off put some new plugs in it. but i really think it has something to do w/ the o2. i have a feeling that at least one isnt even connected. i have to try to follow the wiring all the way through and make sure its all good. what kind of mpg would you expect if there was a disconnected o2?

 

[Shoaz]

Have you pulled the codes? That will tell you of any significant sensor failures, including the O2s. If something has gone that wrong the computer may likely know about it.

 

[laxmax327]

o yea, sry there wasnt a single code. forgot about that, when i first got it, there was many codes, including 1 about a bank being lean or something. o2 sensor i would assume. but after i put the new ones in that code went away. so i guess the o2 sensors are hooked up ok. id like to clean the maf, since i generously oiled my k&n not thinking about that. but if anything, wouldnt oil on the maf just make the car run leaner? but anyway, no codes anymore. at least that was a week ago, ill go do it again just to be safe.

 

[silversho89]

Cleaning the maf is easy. Just unscrew the two screws securing it. You do have to be extremely careful with those however. I use the enviroduster stuff and a q-tip. Spray a very small amount on the wires inside the sensor. Try not to spray them directly as they are very delicate.

Now with the q-tip only use the little pieces of cotton that are hanging of the tip. You really never touch the whole qtip to the wires. And twirl the qtip on the wires gently. Thats how i clean mine and it seems to work good.

BTW, a bad ect could cause poor gas mileage. It can make the computer think its not warmed up to operating temp and thus leaving the computer in open loop. Theres many variables that could cause this.

Hope this helps.

Rob

 

[F-22 Raptor SHO]

NO NO NO....do not clean the wires in this manner. Go to your parts store and buy electronic contact cleaner...spray the wires off with this stuff. Touching the wires with q-tips could lead to damage.

An mtx getting 10 mpg with no codes tells me your brakes might be sticking really bad. Jack up the rear wheels and spin them. I bet they are not turning well. My E brake cable sticks alot, I dont use it as a result. The latches in the back could be rusty as well as the cable ends. The rear lines could be bad as well.

 

[laxmax327]

yea i do have a brake issue like i posted in another thread. still working on it at the moment. the wheel is somewhat hard to turn, but is turnable, but i thought this would usually just **** a few mpg. could it really be cutting it in half? and ill try that electronics cleaner.

 

[seraphiem]

Fix your brakes. THen see what your mileage is.

I had tanks as low as 8 mpg with my ATX when my back brakes were sticking (collapsed hoses).

 

[etc1006]

Although my car isn't on the road yet... Fix your rear brakes. My left rear was dragging real bad. Replaced the hose and its fine now...

 

[F-22 Raptor SHO]

that is your problem...if its hard to turn thats where your mileage is going.

 

[laxmax327]

ok thx, will get that fixed asap! crappy weather and working outside no go hopefully i will do it in the next couple days. just didnt think that it could affect it that much. ill fix it and test out new mileage at let you guys know, thanks for the advise!

 

[shoebilly]

Keep in mind the more you work this motor the more gas it will use. With good brakes its entirly possible to get as low as 5-7 miles to the gallon if your foot is in all the time. To get maximum mileage you would never hit 3000 rpm.

 

[lennybritz]

I had the same problem before and had the 60K tune up done on it and cleaned out the EGR valve, and it ran a lot better and got 25mpgs afterwords. The month or so before I was getting 11mpg. Also make sure that your spark plugs and wires are good. I also had a dead cylinder because of a wire.