I got a jdm b16A in a 98 civic with a gsr ecu.
Ive done a full tune up, wires, cap, rotor, plugs, oil, air filter, etc.
A few months ago it was giving me 230-250 miles to the tank. now it gives me 180-190. I dont know what it could be.

 

CELs? Poor driving habits?

 

Tire Inflation.

http://www.ehow.com/how-does_4683784...-mileage_.html

 

Wrong ecu.....unless you've stepped the ecu down from OBD2 to OBD1 and are running a P72 with P30 maps

 

a P72 will still run a B16, and that doesn't explain why his mileage has gone down using the same ECU.

Trust me, it's your tire pressure.

 

Of course it will run, but eventually the wrong ecu/map will take their toll on the engine components/sensors

While I agree that tire pressure should be checked and adjusted, I also believe that running the correct ecu/map is paramount.

 

You are TOTALLY preaching to the choir... but I honestly think this problem is a whole different bag of worms.

That being said, it scares me how many people think they can use any old ECU, or run a "chipped" ecu with a god-knows-what fuel map, or run a built motor on a stock ECU and injectors. That's why I would NEVER consider buying someone else's "built" or swapped motor.

 

I was thinking of getting a p28 and then getting it street tuned.

No my driving habits are good, I shift at 3k-4k, and I dont dawg it.

Im a check that tire pressure.

A buddy of mine told me to check fuel inj. or my catalytic converter.

 

If you don't have a CEL, and you haven't been beating it, and you haven't changed any parts... there's honestly not a whole lot else it could be.

Bad o2 would throw a CEL, bad cat would too. Bad ring you'd see smoke, blown head gasket you'd know as well. Clogged injectors MIGHT effect your mileage, but I think you'd be running like crap.

Check that tire pressure and get back to us.

 

Thats the funny thing, I have no leaks or anything, its a clean motor. The only thing that Ive put on it is a air intake.

Im a check that sensor and tire pressure, and Ill get back with yall. thanks

 

oh one more thing it runs rich, its a different smell. idk

 

If your tire pressure is ok, trying running the correct ecu for the engine

 

Running rich will definitely effect your mileage. What makes you think it's running rich, the smell?

 

Yea ima check them little things first. tire press., ecu.

Yea, sometimes when im stopped at a light I can smelll fumes, and it wasnt like that before.

 

When was the fuel filter last changed?

 

YEA, UM...I dont recall ever doing that lol

 

Overinflate tires by 5 psi.

Get a new Denso or NTK oxygen sensor from Amazon. Use Denso's and NTK's web sites to figure out the correct model. It should cost around $50.

Change the PCV valve. It should cost around $25.

Else try the tips at http://sites.google.com/site/hondali...gasmileagetips

 

if u are running rich and it smells u may have a bad map sensor that is stuck in closed loop. if its stuck in closed loop operation its gonna run rich and the ecu is gonna tell the engine to keep dumping fuel which may cause your smell that u have. get the correct ecu for your engine and replace the map sensor