Hope you all will be doing well. I have a strange automotive issue to share here and I hope all of you can suggest something better to resolve it.
I have a CF4 Civic 2004 prosmatic very carefully kept and timely maintained like oil changes, filters, plugs and tune ups etc. But its fuel consumption is almost like 1KZ FJ90 Cruiser 6-7km/l. Therefore I decided many times to sell it and buy the FJ again, however I would like to give it a last try that if there is any solution to increase the fuel efficiency again.
The existing engine setup is as follows:
Original main block was D16W9 (The one comes in PKDM Civics) but now changed to D15B (JDM) afterwards because of broken timing belt`s damage to entire assembly.
Transmission is also replaced with one taken off from D17 (same number of speeds)
Rest all setup is stock like ECU etc.
My acceleration pattern is very soft that I mostly drive within 2000-2500 Rpms
Regarding the fuel, I understand that many of the fuel pumps does not give the full quantity, that is why I only get my tank filled from very specific and well reputed petrol pumps i.e. (Caltex DHA-Y Block Lhr).
Few months before I use to get precisely almost 9-10 Km plus in city with and without AC but now it hardly gives 7-7.5 Km/l in city without AC.
I have done following things many times for the tune-up and other precautionary measures:
TPS Sensor Adjustment 4.49 - 4.50
Throttle body cleaning
Butterfly gap is still intact
Idle control valves works properly to maintain the RPMs on stock level.
Appropriate Oil grade
Air filter etc etc
Previously someone suggested me to turn off the V-techs by taking solenoid`s grip off but that didn?t worked as well.
I will really appreciate if you guys can come up with best possible idea/solution as I really want to keep this car with me. Many Thanks
Note: For any more technical info please feel free to ask.