civicEX1995

hello, my EJ1 y killing me with gas!!.. i only getting 17mpg running with a/c

i have an D15b Vtec JDM and P08 ECU, no CEL code, i have replaced fuel filter, fuel pump and fuel pressure regulator, spark plugs and wires, rotor and cap, set the timmig to spec. those parts was changed trying to find the problem and no result

all in the car it seems to be good except that problem.. any suggestion?

jdmh22eg2

My suggestion would be graph o2 with labscope or test o2 with multimeter

civicEX1995

i forgot to post that.. 02 sensor is a new one..

Singlejinglez6

Doesnt mean its not bad! Ive bought plenty of new parts that turned out to be faulty as well.

EJ8_Man

Spend a lot of time sitting in traffic with the AC running?

civicEX1995

not really, the only thing i have noticed when A/C is on, is that i fell the car a little heavy when accelerating

furious94ls

Make sure you don't have any dragging calipers. Also, that the plugs/wires/cap/rotor/pcv valve air filter, are all new or in good condition. 17mpg is bad. I'd say only if you were in all city traffic with A/C on would that be about right. My 98 EX gets 30mpg 50/50.

jdmh22eg2

Yea deff have seen "new" LAZY o2's. And even my ls w/itr trans beating **** out of it gets 25 in city (no ac yet, been lazy and near end of summer in fl)

civicEX1995

i dont thing dragging calipers cuz when a/c is off the i cant fell the car heavy, this only can be feels when a/c is on... all other parts are in good condition, i have checked all again yesterday

furious94ls

Something has to be wrong. These cars don't get 17mpg. Try a tank with no A/C and see what happens. I use the A/C in my car and the lowest MPG I have gotten was 28mpg.

jbpnoman

How did you arrive at this number? Next time you fill up your tank, completely top it off. Reset your trip meter. Drive to approximately half tank. Refill again, completely topping off again. Divide your trip meter by the number of gallons on the second fill. Give us those numbers, and we can work from there.

While you're at it, test your fuel pressure. Also, where are you getting your gas?

civicEX1995

the last time i fill up the the tank (monday) was 8.6 gallons and my odometer was 135 miles, today my car has 50 miles and fuel gauge is a little below here a picture

civicEX1995

update guys, i was cheking the fuel pressure regulator, and i thing is stuck cuz if i pull vaccun with my mouth, i cant feel the diaphragm moving, is that normal or its stuck?

greenteadude

yes,, its suppose to move when vacuum is applied

civicEX1995

o God, i need to change that again hehehe

look this Fuel Pressure Regulator


is good idea buy those or go for OEM?

jbpnoman

Go with OEM.

Also, check your gas mileage the way I posted. What you're doing is completely inaccurate.

civicEX1995

i follow your suggestion i do exact what u do and guess what, mi trip meter was 63 miles and the tank fills with 5.6 galons thats = 11.86 MPG

jbpnoman

Ok, you're one for three so far.

Test your fuel pressure.
Where are you getting your gas, and what octane are you using?

civicEX1995

Im using 93 octane with octane booster aditive is like 98 octanr, my fuel pressure regulator is stuck, i saw it yesterday, today i will buy another and change it , i'll let u know when i changed

civicEX1995

Update.. changed Fuel Pressure regulator, also cleaned injectors there was an injector stucked was not spraying the gas as it should and also do a compression test

Cylinder 1 = 150
Cylinder 2 = 150
Cylinder 3 = 150
Cylinder 4 = 150

all are equals, now lets check

civicEX1995

update... Yesterday i was checking the TPS voltage and found that my TPS was messuring 0.8v when it should be 0.45v.. i moved the TPS back to 0.45v and when the car gets operating temperature the idle start to fluctuate.( my IACV is a new one, even the problem happen with other 2 valves i have in my house).

some thing weird is when i close all the idle screw the fluctuating disappears but the car has very hard aceleration..

any idea?

jbpnoman

Your HX doesn't need 93, and it doesn't need octane booster. Are you buying cheap gas, or top teir gas?

Did you check your gas mileage after the FPR replacement and injector cleaning, but before fiddling with the TPS? Did you properly calibrate the TPS according to the service manual procedure? Did you calibrate the IACV after recalibrating the TPS?

GringoZX

Why are you running 93 octane? plus octane boost? if the engine runs fine (no knocks/pre-ignition) on 87 octane then the higher octane is just a waste of money. also because of the way the higher octane fuel burns, that will decrease you mpg as well.

fleabag

I suggest OP clean all of his electrical grounds, then measure them with a multimeter. It should say 0.0 Ohms from the ground point to the battery negative terminal. Check every ground point, and if its showing something like 0.1 ohms, then you should get cleaning! Don't scrape any paint off! There is no way in hell OP would be getting 17mpg on this car, something is most certainly wrong! If this was an OBD-II car, it'd be easier to diagnose because we could check the idle GPH. You said your car struggles to accelerate, right? If you disconnect the map sensor, does the car drive more normally? I'm not saying keep it disconnected like that because the GPH would climb from maybe .2-.4gph to 2.5gph which is WAYYYY too much. Just saying, that it could show that something is giving the computer bad A/F readings or something. You want this car to be fixed before you overheat your catalytic converter!

civicEX1995

im using 93 octane because with 87 my engine knocks

im cheking the gas milliage after FPR replacement..

i was calibrating the TPS according to service manual, but when i put the TPS at 0.45v (exactly like service manual) the idle start jumping.. i didnt calibrate IACV after recalibrating the TPS.. how can i do that, can u teach me please?