03 Explorer 4.0 multiple cylinder misfire
A few months back I bought a 2003 explorer 4.0 4X4 with
170K miles. It ran perfect until recently it developed an
occasional misfire at highway speeds that gradually got
worse over a couple weeks, to the point where it wouldn't
accelerate over 75-80 mph because it would misfire so
bad. It would still idle good but it'd only do it when trying
to pass or on a steep incline, then one day after it
misfiring nearly the entire 50 mile commute to work, i go
to start it after my shift and it will barely idle and has no
response when I gave it gas. I attempted to drive it and
it's top speed was about 10 mph and would die shortly
after taking off. At this point, the check engine light comes
on for the very first time since this all started and starts
blinking so I had no choice but to park it. I get a ride home
and come back the next day with a code scanner and get
four codes: P0300 - random/ multiple cylinder misfire,
P0301, P0302, P0303 - misfire in cylinders 1,2, and 3. I
changed the coil without any luck then had it hauled home
on a trailer. At this point it stalled about 15 times (no
exaggeration) before it was backed off the trailer. I later
changed the fuel filter and I'm still having this problem. It
hardly won't even fire now. It'll start if you try long enough
and but most the time it only cranks. White smoke comes
out of the exhaust and it smells like unburned gas. I'm
waiting on new plugs and wires to be delivered , although
I doubt that's the problem, I'll just go ahead and change
them to rule it out. My question is, is there anything that
commonly goes bad on explorers that would cause it to
misfire on 3 cylinders? And what can cause misfires only
on one side of the engine? Why does it have no response
to throttle? I need help diagnosing this problem and would
greatly appreciate any suggestions of what to do or where
the start. I don't want to spend a lot of money throwing
parts at it because it's not even worth $2k. Thanks a lot in
advance!
