Horrible gas mileage...

[albert_ey]

Hello everyone... I own a 1989 240sx ka24e no mods, completely stock.

The other day I drove to palmdale and back and used up 3/4 of my tank. I was looking at the capacity of the tank(I think the capacity is 16) and the miles I drove and I estimated I am doing about 180 to a full tank. Palmdale is about 70 Miles from L.A. that's 140 round trip and I used up 3/4 that's 12 gallons... I drive no faster than 70 and take it real easy on the hills. The average MPG for a 240 is 23. I get nothing near that.

Anyone have any Ideas?? Maybe O2 censor??Thanks in advance

albert_ey

[ermster85]

you should probably check your fuel filter, and try some injector/valve cleaner,,,,,,,,,,

[480sx]

Whens the last time you did a basic tune up? You should first run a bottle of injector cleaner + high test through your engine. Then change the cap, rotor, wires, plugs, fuel filter. You will see a big gain in fuel econ. If you really want to do something, you could run some Seafoam through it too. GL

[albert_ey]

Thanks for the response guys, I have recently changed the cap, rotor, plugs, wires. I will change the fuel filter tomorrow(I completely forgot about the filter) , then I will try the injector cleaner. I have never used injector cleaner, does it go in the tank? what is high test?

I also have no Idea what seafoam is, but i'll do a search and figure it out myself.

Thanks for the great response. You have been very helpful.

albert_ey

[480sx]

Injector cleaner is a liquid that goes in the gas tank. High test is the most expencive gas, with higher octane ratings than the cheap stuff. It will also clean your head out along with the injector cleaner.

[albert_ey]

Thanks!! I changed my fuel filter and added some Lucas Injector Cleaner, It has gone back to what I have calcualted as normal gas mileage... Thanks, your advice has saved me a lot of money. I will also be sea foaming my engine soon.

Thanks,albert_ey

[Katapl]

I will also be sea foaming my engine soon.

Seafoam is the greatest. You'll likely end up getting even better mileage after you run it through. Read up on it and go for it!

[nelson8708]

its always a good idea to check to make sure you base timing is correct as well. I just started to get horrible gas milage this past week and turns out my wastegate diaphram went bad and started leaking so i had a pretty big vacuum leak. I fixed it tonight and hopefully i will see a difference next week. Went from 25mpg (highway) to 20mpg (highway) in one week.