mtulett1

my '05 FX4 boggs down while trying to accelerate out of overdrive always around 1200 RPMS. i'v changed everything sprkplugs , coil packs fuel filter, cleaned MAF, replaced FPDM and O2 sensors. If i shut off the Overdrive it runs fine no issue whatsoever. Any help would be appreciated thanks.

Tommy J

I'll repeat what I was told. What plugs did you use? Did you replace the boots and springs on the coils. What about air filter and is the foam around the filter area missing. Try cleaning your throttle body. Any codes? Throttle position sensor acting up?. Im not trying to be a smart *** but its probably what you"re going to be asked. It is weird though that it only does it in OD. Someone smarter than me might have more to say

Rick_F150

have you recently when in mud or somewhat deep water

Rick_F150

i had the same problem and i was told some water may had when in the crank sensor. its in a poor location where water can go in and stay...
i have misfire codes and such i few pistons.
i had pick up new spark and i didnt had time to replace them everything went back to normal after a hot day.
i assume the sensor dried up and stop sending false info to pcm

powerranger262

He replaced the fpdm already. Your cats could be plugged up.

mtulett1

so i changed out the coil packs and now i'm getting misfire codes on cylinders 3,4,5 and a bank 1 system lean code. does a clogged cat cause a misfire code? the coilpacks are those expensive yellow ones should i just go motorcraft on those?

lewissa81

Swap out the coils from cylinders without a misfire code to one's with misfire codes. Example: swap 1&3, 2&4, 5&6. If the codes follow the cop's, then they are bad (or the boots and springs). If the codes stay with cylinders 3,4,5, then it's not the coils causing the misfire codes.

mtulett1

so i swapped the coil packs and the same codes came up. no lean codes yet just the misfires. the spark plugs are changed too along with the coils. what else would cause that misfire?

vintageman

Did you clear the codes or disconnect the battery when you swapped the plugs and COPs? If not, I would clear the codes and see if the same ones come back again just in case. Have you checked the fuel injector or injector plug at the misfire cylinder yet?

techrep

iTrader: (1)

sounds like a clogged cat...