15 MPG Avg... Anyone else with me?

[Shadow_S14]

So I've realized that my car is getting shit gas mileage. I have nothing in my car; it's a stock '95 KA24DE. I know some people get a 22-25 avg on their KA's. I am at a dead end and can't find an answer. I've changed the fuel filter, cap/rotor, plugs, wires, top O2 sensor. If anyone has any ideas as to what it could be let me know. Could it be an EGR (random codes on it) or temp sensor related problem?

[spooled240]

How many miles? Maybe your cat is getting clogged. Check your timing too.

[Livid_240sx]

Clogged injectors, lay off the throttle and brakes, carbon build up in combustion chamber.

Sent from my SCH-I535 using Tapatalk

[blessedhellrider]

yeah , i get bad mileage too ,but i stay in boost alot .

[kruked]

yeah , i get bad mileage too ,but i stay in boost alot .

Truth


Stpdmssglngth

[Shadow_S14]

Car is almost hitting the 200k mark. Could be that the cat is clogged, I'll check, but timing is fine. I was also thinking the injectors, any one know a good way to check them? And yeh it's sad how I'm wasting as much gas as a boosted car...:down:

[Zeratul]

Turn on the car and look underneath the hood to see if any of the clamps for the fuel lines have come loose or if any of the rubber fuel lines have ruptured. Use your finger to poke and prod the rubber fuel lines to see if they leak from movement.

[S13alldayyo]

My sr gets like 25 mpg lol hopefully a tune can get me to 30+ it's only a 4 cyl


Sent from my iPhone using Tapatalk

[theultimatehero]

Is the engine running normally? I had a bad knock sensor that put my engine in limp mode. Fucking terrible gas mileage during that time.

Sent from my HTCONE using Tapatalk

[frankies1390]

+1 on knock sensor and or cat

[S13alldayyo]

Do you guys think 300 miles per tank is good?


Sent from my iPhone using Tapatalk

[S14.5patches]

I was getting bad mileage in my car had a injector go full retard and replaced it, gas mileage is a tad better with the new injector id replace them with new ones there expensive but itll feel more peppy and give you better mileage. Did for me at least.

[Dima1127]

This might sound pretty stupid, but check your fuel lines for leaks, i had this problem before i was breaking my neck until i sat on a curb next to my car and noticed a drip behind the wheel, and it was gas. its doing better then a Prius now

[sleepyS14se]

Do you guys think 300 miles per tank is good?


Sent from my iPhone using Tapatalk

my stock ka24de (95 s14) gets MAYBE 270 to a tank.


And i just have no aspiration to check the codes because my s14 is one with a obd2 port but will not communicate with my snap on solus scanner. So i said to hell with it.... i am too lazy to do the BS required to pull the codes manually from the ecu.

[JBB]

stop shifting at 7k :)

[sleepyS14se]

i can't lol

[Shadow_S14]

So I checked the Cat and all seems well. Although now I'm thinking it might be the knock sensor. I'll check it out soon. Injectors as well.
I too thought it was a fuel leak, but I traced lines from tank to rail; no leaks.

[nismoka]

Could try some injector cleaner first


Sent from my iPhone using Tapatalk

[sleepyS14se]

seafoam

msglenth

[turbos14]

Do a professional injector clean, check base timing, egr helps gas milage if its not working then u will lose its help and possible run hotter which the computer will pull timing and dump more fuel to cool. To check how the engine health is you could do a compression test and vacuum test.

Sent from my SGH-I747 using Tapatalk

[hollerjeet]

when my sr had a crazy drop in mpg but no change in anything else, ran fine, etc. etc.. it turned out to be a hair line crack in the exhaust manifold ( on the side so i couldn't see it from the outside). i replaced it with another one and bam.. everything good.

do you smell a exhaust leak anywhere?

[Shadow_S14]

So a quick update on my gas issue. I'm getting less miles to the gallon now, down to about 13mpg. There aren't any exhaust leaks that I could tell. I sent out my injectors to get cleaned, didn't change much, so that wasn't the issue. Two codes kept popping up. P0325 and P0400 or Knock Sensor and EGR System. I checked the Knock Sensor; it was cracked to shit so I changed it with a new one and checked wiring on harness/sub-harness and all is good with continuity and resistance. But the code still persists... any suggestions on this one? For the EGR I took out the EGR itself cleaned it out, got rid of all the build up inside and replaced hoses. I assembled it all back and noticed that when I push up the diaphragm in the valve it doesn't stall out or change idle speed at all. Although when I rev the car it does lift up as it should... I'm a little stumbled here, any insight would be great.

[Livid_240sx]

Does your 14 feel bogged down? Are you having to slam on the gas to get her going? 10/10 I bet your in limp mode. Swap out your EGR.

Sent from my SCH-I535 using Tapatalk

[Livid_240sx]

Try a compression test. You might be burning oil. You could have some fried piston rings. It could be a culmination of things.

Figure it out before this is you

http://ricecop.tumblr.com/post/78999950790/automotivefun-chadbee-pure-carnage-lol

Sent from my SCH-I535 using Tapatalk

[zerodameaon]

Engine coolant temp sensor will do exactly this, turn your 25mpg car into 10-15mpg. I am surprised no one has mentioned that yet.

[Shadow_S14]

Changed the CTS, let's see if it changes anything. I'll try the compression test to see how my engine is doing internally.

[A54]

good ideas...

[mechanicalmoron]

Run some techron (the more expensive one) through it.

Remember that you directly choose how much gas you burn - the ECU must match the amount of air you admit with the throttle, to keep the AFR correct. (you can really tell if you have a pod filter, and hear the sucking - I don't really remember if you can tell with the stock airbox, if that's what you have).

Even if you're easy on the throttle and keep RPM's low, you're talking about freeway milage that other people get. On the highway I get great milage (AND with a super low compression, smoky, half dead motor), when I can make myself act like an adult with the throttle. In town? probably 8-18, depending on exactly how grown up my driving is.

Pretend you're driving a limo, and see how your milage improves. But either way, in town milage is MUCH worse. Starting uses a huge amount of energy, and stopping wastes a huge amount of energy.

[Livid_240sx]

https://www.youtube.com/watch?v=uwzaWvbEzEE&feature=youtube_gdata_player

Like a limo, eh? Sounds like it could be fun.

Sent from my SCH-I535 using Tapatalk

[Livid_240sx]

in combustion chamber. http://sister.thewindowdi.com/4.jpg

What is?

Sent from my SCH-I535 using Tapatalk

[Mile High Silvia]

clogged catalytic converter?

[zerodameaon]

What is?

Sent from my SCH-I535 using Tapatalk

That would be spam. If you see stupid posts like that just report them.

[mechanicalmoron]

So a quick update on my gas issue. I'm getting less miles to the gallon now, down to about 13mpg. There aren't any exhaust leaks that I could tell. I sent out my injectors to get cleaned, didn't change much, so that wasn't the issue. Two codes kept popping up. P0325 and P0400 or Knock Sensor and EGR System. I checked the Knock Sensor; it was cracked to shit so I changed it with a new one and checked wiring on harness/sub-harness and all is good with continuity and resistance. But the code still persists... any suggestions on this one? For the EGR I took out the EGR itself cleaned it out, got rid of all the build up inside and replaced hoses. I assembled it all back and noticed that when I push up the diaphragm in the valve it doesn't stall out or change idle speed at all. Although when I rev the car it does lift up as it should... I'm a little stumbled here, any insight would be great.
Did you torque the knock sensor correctly?

I believe that not only can over-torquing destroy them, but under or over, and they will not read right, and the computer will tell you something's off.

[FaLKoN240]

What happened when you changed the CTS? I changed mine and it's made a difference I think...

[Shadow_S14]

Oddly enough, after changing the CTS the knock sensor and EGR codes went away. Now I have codes 12 (MAF?) and 76 (Fuel Inj.). Yes, I torqued the knock sensor to spec. Also my O2 sensor(primary) is dead. I changed it a few months back; is it possible it's dead already? I took it out it's black as f**k!

[FaLKoN240]

If it's black that means your car is running rich. Which may be why you're getting crap mileage.

It probably is black from the faulty CTS thinking the car was cold. Corrosion is an insulator (resistor) which will send the wrong voltage to the ECU making it think the engine is cold, putting it in a cold start AF mixture.

I might be wrong but my limited knowledge on how stock cars operate makes me think this.

[turbos14]

Black is rich and if it was bad for awhile it could have ruined your O2 sensor and worse your cat. Are you getting any codes currently and what are they?

[Kingtal0n]

I am putting down a legit 25mpg automatic stock KA24DE 97 driving spirited around town.
IF I drive it easy around town I can top 27mpg.

Highway is about 30~mpg, below 74mph. At 82mph I only get about 25-26 mpg.

Method used:
Top off tank, drive X miles, Top off tank, divide mileage/gallons. Done this repeatedly since I owned the car for precision.

[Shadow_S14]

27? Holy shit! Well the CEL turned off and I'm not getting any codes; only 55 which is all good. Is it weird that everything seemed to fix itself after changing the Temp Sensor? I'm still not getting results...

[solo_ryder]

My average on a healthy 96 ka 5 speed mixed is 8.6l/100km which equates to 27.35 mpg. Thats 60/40 highway/city with me driving it normal with some WOT runs. All I had at the time of those recordings was a 3" catback. Everything else 100% stock 87 octane. Double check your timing and look for exhaust leaks.

CTS as others said will cause the car to run rich if it cant read temps. Make sure your air filter is clean, fuel filter is clean etc.

[turbos14]

Too bad you don't have a scan tool to look at your vehicle data. Like short and long term fuel trims which shows if you are running rich and by how much, plus able to see o2 readings and such. How are you checking your codes?

Sent from my SGH-I747 using Tapatalk

[Shadow_S14]

I was using a Diagnostics Scan Tool and have also been checking the codes directly through the back of the ECU.

[turbos14]

If no codes and you have plenty of miles since last clear then nothing is too far out of specs. I would then check and make sure everything is tip top. Like timing, throttle body intake air control and intake are clean along with maf, idle good, and a compression and leak done test for internal health.

Sent from my SGH-I747 using Tapatalk

[Zzz89]

Also try spraying your MAF with CRC MAF cleaner. I had a dirty MAF which threw a leaky injector code and caused the car to run rich.