Horrible Fuel Economy

SON240sx Automotive
1

Hey guys. I am getting horrible fuel economy on my vert. I’m talking 250kms on a full tank of 91 octane. Just wondering if anyone can give me any suggestions on what to do. The car has a stock KA24DE. It passed a valid e-test but the CO rating was a little high. I think this means the car is running rich right? Here is stuff I’ve already tried:

  • changed O2 sensor
  • changed fuel filter
  • did an auto to manual swap (thought tranny was slipping)
  • changed TPS (I don’t know whether I swapped a good one in so I am going to try the one on my other car since I know its working)

In the next couple of weeks I am going to be changing the thermostat, replace the coolant temp sensor, do a coolant flush and replacing the plugs and wires (even though they look good). Does anyone have any other sugestions?

2

make sure your gas tank isn’t leaking. i had the same problem with mine.

3

gas tank ud smell it. umm air filter plugs wires. your foot.??

4

http://img.photobucket.com/albums/v729/Silvia_Drift/DSC01953.jpg
DSC01953.jpg800×600

^I highly doubt your fuel lines or gas tank are rusty or crappy enough to cause poor milage…

5

and i highly doubt you could drive a stock KA hard enough for long enough to get 250klm per tank without realizing that this is what the problem is.

ka’s get better mileage than that on a race track almost…

6

Coolant temp sensor.

Could be randomly running into cold start mode.

The FSM tells you how to test it so go test it :o

7

Hmm, I can’t find this in the FSM. What section is it in?

8

isnt your vert from the states?

if so did you change the cluster? or it will still be reading your trip meter in miles… but im sure you know that!

just pointing that shit out… if it helps

9

Lol, I’m such a retard. You’re right man.

My fuel economy still isn’t as good as it should be though. Thats about 400kms a tank on 91 octane with about half highway mileage. I need to check out that coolant temp sensor.

10

400km! shoot im lucky to get 300km sometimes!!!

11

Really? I got 500kms a tank on my KA-T. That is if I’m not boosting lol.

12

Yeah walter gets like 500km too.

haha

13

400km/tank might be ok if you are constantly driving in the city… also your vert is much heavier than a regular S13 hatchback or coupe…

14

my auto vert did about 550 highway driving

15

Do the KA24DE’s have a knock sensor? I can’t remember as it’s been over 2 years since I had my 95 240sx, but if the knock sensor is kaput, then that could explain your horrible fuel mileage.

16

Well the 400kms a tank was mixed city and highway driving. The vert is a little heavier than the hatch or coupe. It is a bit over 3000lbs.

And I am pretty sure that it does have a knock sensor.

17

I got 550km on 94 octane and I dont have a knock sensor. Although I would like the plug if anybody has one to give me.

18

Where do you normally drive? Stop and Go city driving or highway?

19

i also have bnib ngk wires let me know if interested

20

Well the tank that I got 400kms on was the highway drive to Dunnville racetrack, only 15 laps of ripping the car on the track (then it broke), the drive back to Mississauga from Dunnville, and the rest was city driving. And Ted, how much for the wires?