2000 Ford Truck engine started to missfire

2000 FORD TRUCK
180,000 MILES • V8 • 4WD • AUTOMATIC
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RCHANSON
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  • 1 POST
Recently my engine (5.4L) started to miss on #4 cyclinder and also the OBD 2 said there was a lean fuel mixture on Bank #1. I just got through driving through some deep snow and filled up with gasoline. Before this all happened I always had to be careful not to spray wash my engine as it would missfire due to the moisture. Where should I start looking to see what the problem really is. Could it be a dirty fuel injector?

Thanks
Ron
Mar 10, 2009 at 5:38 PM
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RASMATAZ
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Check sparkplug/compression/injector for no. 4 cyl

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)
Mar 10, 2009 at 5:50 PM