okay i swapped in a d16Y7 into my 1995 honda civic cx, The motor is a 99 with 80k on it new t belt,waterpump,oil pump. but anyways i have had it in my car running as a dd for about two months and on a full tank i get about 140-180 miles. What is wrong with it? i also put a d16z6 IM on it before i swapped it in. i would think this d series would get over 250 miles off a full tank!? but i have tried adding injector cleaner stuff in the gas,seafom etc...nothing works. what should i look into replacing? fuel filter? fuel pump?injectors? etc... LMK what i should do you guys i baby this motor too get the most out of it but still the same and motor just passed emissions yesterday so its not running rich or anything. i did notice my i believe Co2/CO was high limit is 20.00 i got 18.888. thanks for reading any help will be appreciated.

 

throwing any codes?? maybe jus needs tune up plugs wires etc.

 

how is the air filter?

 

damn that is pretty bad, i get close to 400 miles per tank on my y8. Check yar fuel system to make sure you have no leaks of any sort, check the seal under the seat where the fuel pump is, and any leaks in the lines??

 

no leaks at all anywhere in the lines etc... and not throwing any codes. i am using a p06 ecu on this y7 swap.

 

BUMP

 

i had the same exact problem

20 mpg and truthfully i still havent figured it out. I just swapped it out for a y8 this weekend. Upon swapping i noticed my pcv valve is fubared

so go and get that changed and see if that works its a 5 dollar part. My friend said it was that when we were swapping motors.

 

I also was getting crappy MpG when i had a y8 in my car. changed the plugs and fuel filter and i was pushin 440 to a tank with that thing.

 

Same **** here 170-190 miles per tank on a JDM D15B Vtec!! Still cant figure it out maybe injectors?

 

you replace your PCV valve?

as someone else said spark plug/wire?

 

CHECK YOUR FUEL PRESSURE AND YOUR O2 SENSOR!

 

check the pcv....no one ever changes them since most are a bitch and are under the intake manifold....its a cheap little part...was like 9 bucks for my hx....but for a cheap part if yours isnt working right it will make a world of difference in mpgs and idling

 

change your oil

 

Check o2 sensor too.

 

I have this problem, and I see this thread left and right!!!

omg why wasn't I warned??? I figured on a 97 (10 yrs old) that 20mpg was decent OMFG!!!

 

Any progress?

 

NO NOT REALLY I HAVE REPLACED THE FOLLOWING: O2 SENSOR,fpg,PCV,OIL,INJECTORS,FUEL FILTER,FUEL PUMP, STILL GETTING 150MPG

 

damn i wish i got 150 mpg!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -HONDA- &raquo;</TD></TR><TR><TD CLASS="quote">NO NOT REALLY I HAVE REPLACED THE FOLLOWING: O2 SENSOR,fpg,PCV,OIL,INJECTORS,FUEL FILTER,FUEL PUMP, STILL GETTING 150MPG</TD></TR></TABLE>

EXPLETIVE, man! what else is there to change??

BTW, How are your driving habits? Lead foot? Hilly area? also, is that city, or HWY? (I forget)

 

in my y8, i get roughly 300 per fill up and resulting in around 28-30 mpg.
How are you calculating mileage?
Do you:
A) just look at the tripometer and just call it or B) reset to zero at the last fill up and then do total mileage ran since then divided by the number of gallons filled up the next time?
Maybe a bad ECU?