Hello,
I have a 2006 ford expedition 5.4 (also a 2001, but she has always been good to me) and I have an issue with PCM codes that show cyl 3 and 7 are mis firing and also have the code of multiple mis fires. I already swapped the coils from 3 and 7 (checked plugs as well) to others cyl and the problem did not follow. From what I read it seems like more of a control system problem since I am getting the multi mis fires. I also replaced the fuel flter. I noticed the cruise control does not set unless i floor the throttle. Also the air vents seem to switch automatically from time to time while driving. So leans me to think it is a vacuum leak. I looked at all the hoses and did the carb cleaner trick and nothing. Looks like on this model there is no fuel pressure regulator. There is a fuel pressure sensor that I messed with, but seem to have no effect. I removed the vacuum hose (check the vacuum and was stable -25 psi) and attached a hand pump and went up and down to -20 psi and no change in the way the motor ran. I read something FPDM that controls the fuel pump. going to check that tomorrow and maybe a compression check. Any insight would be greatly appreciated. This 2006 has been a bear. Replaced the throttle body two weeks ago because of on engine failsafe mode.
Thanks,
Walter
I have a 2006 ford expedition 5.4 (also a 2001, but she has always been good to me) and I have an issue with PCM codes that show cyl 3 and 7 are mis firing and also have the code of multiple mis fires. I already swapped the coils from 3 and 7 (checked plugs as well) to others cyl and the problem did not follow. From what I read it seems like more of a control system problem since I am getting the multi mis fires. I also replaced the fuel flter. I noticed the cruise control does not set unless i floor the throttle. Also the air vents seem to switch automatically from time to time while driving. So leans me to think it is a vacuum leak. I looked at all the hoses and did the carb cleaner trick and nothing. Looks like on this model there is no fuel pressure regulator. There is a fuel pressure sensor that I messed with, but seem to have no effect. I removed the vacuum hose (check the vacuum and was stable -25 psi) and attached a hand pump and went up and down to -20 psi and no change in the way the motor ran. I read something FPDM that controls the fuel pump. going to check that tomorrow and maybe a compression check. Any insight would be greatly appreciated. This 2006 has been a bear. Replaced the throttle body two weeks ago because of on engine failsafe mode.
Thanks,
Walter
