Thread: MPG gone down the crapper

everyone check your fuel sending units and make sure they are working properly!!, especially b13 dudes... before i replaced my fuel sending unit mine was very irratic, it would only take me about 210-220ish on a full take of gas, and not smashing on the pedal, now this past weekend i replaced my fuel sending unit with a new one, and damn it took me 300 miles on a full talk of gas, i filled up in yuma, az. came down to phoenix, on sunday, drove to work (mesa) thats a 55 mi round trip on monday(i laso drove around town to get some errands), today, tuesday, same another 55 miles and finally my low fuel light finally worked and bearly came on... so my old sending unit was reading way far ahead.. it would take me another few miles, but i dont think it will take me another 55mi, so im refueling tomorrow....anyways CHECK YOUR FUEL SENDING UNIT...Peace.......

JR..

When I fill up I'm putting in around 9.5 to 10 gallons of gas so I don't think thats the problem.As of right now I have gotten 215 since I last filled up and I have a 1/4th a tank left last week I was out of gas at 215 so I'm pretty sure it was the E10 crap.

I get about ~270 to the tank on 10% Ethanol, on a DE+T, and spirited driving. I can only get 91 Octane fuel, due to my elevation being around 3700ft.

I've never tried driving it granny style. It's just too tempting to mash it now and then.

So thank you Pretty White for finding the Carbibles.com site. I've been reading information there quite a bit within the last few days.

Check out the fuel page: http://www.carbibles.com/fuel_engine_bible_pg2.html

There is a section about Ethanol... here is a quote in particular:

Where is the sending unit?

Sending units are mounted in tank. The fuel pump is underneath the sending unit, and the sending unit is that huge wierd looking thing that has the fuel lines coming out of it, from the fuel pump. It's just a float, basically.

Any idea on the cost to replace?

you can replace the fuel sending unit yourself its really easy, it only took me about 35min to replace it... just remove your rear seats, there will be a black cover with 4 screws holding it, once you slide that cover aside, youll see the fuel sending unit, theres a black ring around it with 6-8 screws (i cant remember). then simpy disconnect your fuel lines your connectors, then remove the ring and pull up, then there will be other 2 fuel lines attached to it on the bottom, disconnect those, (remember where they belong you dont want to mix them up, simply mark em with white out). then your all set, just install the new one in vice versa... oh and while at it replace the sending unit O-ring tank seal(since its been molested), its only 10 bucks at the dealer...

the sending unit was only 80 bucks shipped at courtesyparts.com

cost of labor i dont know mabe about an hour, and depending what the flat rate is... if its 83 bucks an hour + sending unit your looking at $163ish

Here is the fuel pump replacement How to. http://sr20-forum.com/showthread.php?t=727

Fuel sending unit same as the fuel pump?

You can't get away from the 10% ethanol, not a least where I live - when MBTE was removed, we got ethanol, more of it in Winter. I really notice this in my G Coupe's VQ with requirement for 91 or better, the mileage drops -2 mpg most of the entire Winter season. Shell has it, too, although since I drive the almost same mixed city/rural drive 5 days a week, I did track a local Shell's gas vs. Citgo, and after about 2 months now it's either a coincidence or the gas sold as 93 octane at Citgo is crap, it doesn't get the mpg and motor even stumbles dropping from high revs off idle (as in drop from 5 k to idle, stumbled down to 400 then came back up to 600 or so).

That last part was pissing me off, since I stopped hitting the extra few cents a gallon at Citgo, mpg is normal for this time of year and no more problem.

Also no one asked this, I think, but if you're running an OEM airbox intake, check for blow-by and other crap in the air filter. If you run a cone, clean and oil it. Excessively dirty air filter kills mpg, and here I see a lot more sand-dust in Winter because the roads get salt/sand then dry up. The fine powder makes its way into the air filter, tends to block it up faster than normal when the roads are clean.