2002 Ford Expedition Xlt 5.4L Engine misfires, no power, stall sometimes.

Posted by mellassi on January 16, 2014 under Domestic | Be the First to Comment

Use a scan tool to isolate the cylinder that has a misfire, it could be more then one, then move the cylinder ignition coil to another cylinder, and check again . if the misfire follows, replace the coil. Also it is recommended to replace the spark plugs.

-If the misfire does not follow the coil, move the cylinder’s injector to another cylinder. If the misfire follow, replace that injector.

-If both coil and injector are OK, check power and ground while misfire to the coil and injector to that bad cylinder,if there’s no power or ground , check wire harness.

-If all coils, plugs, injectors, circuitry are proven OK, suspect internal engine fault, begin compression and running compression tests to isolate.

 

2004 Chevrolet Impala 3.4L, V6 hesitates

Posted by mellassi on January 15, 2014 under Imports | Be the First to Comment

customer complain:

Car bogs out when accelerating, idles fine, has misfire codes p0300.

diagnostics:

1-tested fuel pressure, added carburetor cleaner during acceleration, still bogs out.

2-disconnect MAF sensor,retest, runs better.

Possible causes:

.Faulty MAF sensor.

.vacuum leak after MAF sensor.

.MAF sensor power and ground.

fix:

replace new MAF sensor.