Can someone Help me fuel trims?
Asked by tdtony3 Apr 22, 2024 at 05:26 PM about the 1999 Ford Expedition 4 Dr Eddie Bauer 4WD SUV
Question type: Maintenance & Repair
I have a Expedition with a 5.4 engine. At idle my short term is -0 to - 4. & at Long term both banks read -14.
While I am driving my short term is +1 to -3. My Long terms are at 0 & my mileage goes up. I have changed just about everything trying to figure this out.
Can someone please give me some insight on this?
Thanks!
3 Answers
It is running rich at idle. Have you cleaned the mass airflow sensor? Is the engine air filter dirty? Are there any trouble codes?
Hi, thank you for trying to help. As in my question I have done just about everything, Changed air & gas filter, cleaned maf, changed plugs, coils, boots & springs, injectors, egr valve, fuel pump, oxygen sensors, checked for vacuum leaks, pcv valve. I changed fuel pressure regulator & air valve a year ago, I am going to check these two again since it is happening only at idle. the Exp. runs great.
