Fuel economy dropped from 20 mpg to 16 after changing my fuel pump (after market pump). Actually replaced with 2nd after market (different brand because I suspected bad fuel regulator). Pressure of new pump is within range. Had 260K mile on engine before fuel pump change. The following has been done without improving back to 20 mpg: replaced spark plugs/wires, cleaned mass flow sensor/replaced, cleaned fuel system (sea foam;multiple times), change air filter on regular basis. Injectors are original. The old fuel pump struggled to deliver adequate fuel (hard to start). New pump lets engine crank easy. Is it possible that new fuel pump + old injectors = excessive fuel to cyclinders and subsequent loss of fuel economuy? Any Help????? I have no check engine light.
2003 Ranger, XLT, 4WD, 4.0L, 5spd manual, 288K
Feedback: Positive Feedback:
Members who left positive: Members who left negative: