siouxbahrue Posted December 31, 2017 Share Posted December 31, 2017 Even though it probably still says I am a noob, I have actively followed this site for over 7 years. Now that is out of the way. I have a peculiar issue. My subaru is really really Japanese which is awesome but there are some quarky things that one must deal with to drive this car. About 2 months ago my fuel warning light on the dash went out and never came back on. At the same time that problem occurred,my fuel economy dove from 27-28 to 22. Even more recently, I have a brand new battery, it is - 7° out and the car wouldn't start but was fine the rest of the day starting. I am suspecting a ground issue there but wondering more so if these issues are in some way related and if anyone has any suggestions. I have done the obvious. Looked for loose connections. Checked the battery and alternator which came out great. Not sure about the dash light and fuel economy though. Quote Link to comment Share on other sites More sharing options...
moosens Posted December 31, 2017 Share Posted December 31, 2017 Your Legacy was assembled in the USA. So maybe it needs a little more Japanese. The experts will chime in when they wake up , but to me it seems your ecu has selected a default setting. ***** In no way am I an expert here ****** Just my first thought. I’d also check the coil pack for slight cracks , although you didn’t mention and stalling and rough running. Nice here in New England this time of year , eh ? Quote Link to comment Share on other sites More sharing options...
forester2002s Posted December 31, 2017 Share Posted December 31, 2017 Maybe the low-fuel lamp has burnt out. Does it come on briefly (along with all the other warning-lamps) during the starting sequence? 1 Quote Link to comment Share on other sites More sharing options...
montana tom Posted December 31, 2017 Share Posted December 31, 2017 95 has no obd 2 , makes things a little harder to work out. Your knock sensor is a likely suspect for sudden poor fuel economy. Easy to change , other than getting that darn connector unsnapped. No need for OE hit ebay or rock auto for one. Low fuel light should have no bearing on poor performance. If it seems to run smooth ,no shakes then try changing the knock sensor. Quote Link to comment Share on other sites More sharing options...
mikec03 Posted December 31, 2017 Share Posted December 31, 2017 The 95 does have the OBC2 so the OP can check for codes. I get and have gotten 20-24 mpg on the three 95's that I have had especially in the winter, so I don't look at your mileage as anything exceptional. When you say that you checked the alternator and battery, you should supply specific data that you observed. It might help someone guess at the problem. Alternators on the 90's subarus fail at old age. It wouldn't be surprising. The OP should loosen, rotate, and then tighten the ground connection at the frame as well as the battery post connections. It's a long shot but it won't do any harm. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 31, 2017 Share Posted December 31, 2017 A new battery may help with cold starting. Higher CCA rating the better for colder weather. Clean battery terminals and clean connections at the starter and ground cables as well. Fuel economy isn't related to the low fuel light. It's cold, fuel economy is going to drop. Low fuel lights on these cars are not known for consistency. Sometimes mine will come on at 1/4 tank, other times it won't until the needle is pegged below E. 1 Quote Link to comment Share on other sites More sharing options...
mickytrus Posted January 1, 2018 Share Posted January 1, 2018 Yeah, determine if vehicle is throwing any codes.... It is not OBDII but...... (not actually familiar) with but.... I probably does the blinking lite gig... when you turn key... Determine where the blinking lite location is of your OBC2......... I had old Loyaless.... they had the blinking lite gig..... had to remove panel below steering column... but,,,,,,,,,,,,,, Ask where your is..... If bad knock sensor......... I would think you would have a blinking lite code for that active in your OBC2..... I got one on the EEEEEE buh aye......... rather cheap.......(knock sensor) Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted January 1, 2018 Share Posted January 1, 2018 95 legacy is OBD2, 100%. Any of the generic scan tools will talk to it, and an Ultragauge works too. Fuel economy goes down in winter, that's normal and to be expected. All the gear oils and greases are thick in the cold, so it takes more power to move the car, and that uses fuel. Add in the longer warm up time of the engine and the change in winter gas formulation to a more volitle but less energy dense mix and loosing 3+ mpg is normal. If you idle the car in the morning to warm it up, that's more fuel wasted. Second thing is the low fuel light. If you're using that as your indicator that it's time to refill, it's hard on the fuel pump. That light really should never come on, you should be refilling when it gets down to an 1/8 of a tank. Going lower serves no purpose, and it greatly increases the chances of overheating the pump or it sucking air. The light is an idiot light, as in "hey dummy, go get gas NOW", not a friendly reminder. That's what the gauge is there for. If you are calculating the mpg based on a fixed amount of gallons in a "tank full" when the empty light comes on, that's innacurate. The better way is to record the gallons it takes to fill the tank from whatever level it was at and divide the miles since the last time it was filled to the top. Quote Link to comment Share on other sites More sharing options...
heartless Posted January 1, 2018 Share Posted January 1, 2018 yes, a 95 Legacy does have OBDII - 1st year for it in the Subaru lineup. the low gas light never did work on the 95 I had, but then again, I rarely let it get much below 1/4 tank either... and my fuel mileage ran around 27-28 in the summer, 24-25 in the winter - pretty normal. the light itself should have zero bearing on fuel mileage - it is most likely just burned out. the correct way to calculate fuel mileage is to keep a log of miles driven and gallons purchased (i use my trip odometer for this, reset to 0 when I get gas) miles / gallons = mpg - example: 250 miles / 11 gallons = 22.7 mpg Do this over the course of several fill-ups then take an average to get a better idea of overall mpg. Do not rely on just one calculation as a good indicator of overall mileage - there will be fluctuations based on several factors - temps, where you bought fuel, driving conditions, etc. If your mileage has indeed dropped way off, then I would suspect other things besides a dead low fuel light. Coolant temp sensor (the one for the ECU), failing O2 sensor, etc.. Extreme cold weather is hard on cars/car batteries - they do not like it. A magnetic oil pan heater (warms the oil so it circulates easier) or a battery blanket can help with that. Up here in Wisconsin, we regularly see sub-zero temps in the minus teens during the winter months (northern Minnesota gets even lower). You learn to take measures to help your vehicle cope with those kinds of temps. Quote Link to comment Share on other sites More sharing options...
siouxbahrue Posted January 9, 2018 Author Share Posted January 9, 2018 No codes from the car. It is an OBDII. Fuel lamp is probably burnt out. No cracks on the wires or coil pack itself. I have kept a log of this car's fuel economy for 5 years. I am leaning towards the knock sensor. I peered at it. It has a bunch of crap built up around it. Ordered a new one. Will install and let you guys know how it fairs. I suspect it truly is this. I had a 1998 of the exact same car minus it was an auto and I noticed the fuel economy dip when it went bad on that car. However, that car did throw the code. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 9, 2018 Share Posted January 9, 2018 (edited) Knock sensor - most common EJ sensor failure CTS - second most common sensor failure Plugs/wires - should be NGK or OEM Lazy front O2 sensor - almost a quarter century old now Leaky injector(s) Dragging brakes from sticky slides. And of course weather/winter gas can only decrease mileage, not increase it. Edited January 9, 2018 by idosubaru 2 Quote Link to comment Share on other sites More sharing options...
OR'sLonewolf Posted January 28, 2018 Share Posted January 28, 2018 I agree Idosubaru.............start with checking the knock sensor to see if it has 5v.......then go to 02 sensors....... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.