I have a 2006 explorer 4.6, has 178K miles on it. It runs ruff, dies when driving, no power, have gone to auto part store to get check engine read multiple times, last time we had to haul it there. We have replaced fuel filter. all plugs multiple times, all coils, mass air flow sensor, throttle positioning sensor, VTC, done compression check (checks from 155-180), all 4 O2 sensors. After replacing TPS runs smooth until it gets running temp and it starts running ruff again and sounds like its missing. When setting in shop pushed on the gas pedal slowly when tack reads slightly over 2rpm it comes down to about 1500rpms and my foot never moved. But when you hit the foot pedal quickly it goes up to 3rpms. Motor does not use oil, and has no leaks. Any suggestions? Any help would be great. Thanks

 

One of the things that first comes to mind is; just what happens when you depress the throttle all the way down? It gets more air and the air flow sensor tells the computer more fuel is needed along with other inputs and the engine is supposed to respond. There is also a point in the TPS set up that calls for a clear flood mode when the pedal is held to the floor when starting. Sometimes in the process of replacing parts ground wires are left disconnected . It would be a good place to start looking.

 

Sorry should have been more clear. We don't put the throttle all the way to the floor. When the engine gets to 2000rpms it goes back down right away. When we tap the throttle quickly it goes up to 3000rpms but yet the throttle is not all the way to the floor, it quickly goes back down, let go of the throttle and then push on it again to get it back up the engine shuts off. It shuts off when driving and when in N and or P. All the wiring is connected and has no defects. Took it for a test drive and it slowed way down so turned around to come home, stepped on the gas and it would not go much above ideal, heard a popping sound which I'm thinking is the throttle body, and it died turned key back and restarted engine, got back home was only about 1/2 mile from home, ran ok but still missing. So went to O'Reilly Auto Parts and bought a new Throttle Body Motor and will install tomorrow. Hoping it fixes it. We started off with about 5 different codes about 3-4 months ago and last week it jumped to 54 codes (some of these where repeats) then not even 5 days later had it checked after replacing multiple parts it jumped to 64 codes (some of these where repeats). It seems like every time we replace something it runs worse.

 

well i installed a new throttle body motor and that did not help still runs ruff when motor gets to running temp . Went for a drive motor died three times in 1/2 mile got back home do not know what to do now.

 

Our vehicles are pretty smart these days, however , they don't always know when a problem has been corrected or defective parts were replaced. Sometimes we need to remove the negative battery cable from the battery post and hold it against the positive battery cable end to allow some of the adaptive learning it aquired to be erased.
Then when the cable is reconnected to that negative battery post and the vehicle restarted it should be left to idle and reset itself. Some of the codes may still remain, but if the problem has been corrected the codes will go away after a few drive cycles.