Misfire Engine Code V6 | Ford Explorer - Ford Ranger Forums - Serious Explorations

  • Register Today It's free! This box and some ads will disappear once registered!

Misfire Engine Code V6

SteveOReno

Member
Joined
February 5, 2015
Messages
11
Reaction score
0
Year, Model & Trim Level
2006 Ford Explorer
Engine code p0306 keeps coming back. I have replaced: spark plugs, spark plug wires, ignition coil pack, fuel injectors, and crankshaft position sensor. Each time I replaced something I disconnect the battery and when I reconnect the battery the engine code is cleared and it stays off for about an hour of driving. Then it comes back on, usually when the engine drops to idle at a stop light, or sometimes during hard acceleration. It has a rough cold idle, and the hot idle is usually smooth. The gas mileage is normal. I checked the cylinder compression and it is normal. I think the only possibility left is a bad computer, but that is expensive and I already spent 300 bucks on the fuel injectors. Fortunately, I can pass inspection by disconnecting the battery for a while, then driving it for half an hour or so to get the engine codes to Ready (I have a code reader).
On a side note, an occasional misfire will not harm the engine. The main problem with repeated misfires is unburned fuel collecting in the catalytic converter and then burning the cat up (also poor gas mileage and pollution). When the engine code starts blinking, the computer has detected multiple misfires and will temporarily shut down shut down the air conditioner (and try to scare the driver). The blinking is on a fixed timer (about one minute) but that time interval is not related to the actual misfire time.
Another interesting aspect of my engine code problem is the engine will start running worse and worse several hours after the battery disconnect/computer reset, mainly at idle. When I rev the engine up it always seems to run fine. I bet nobody can figure this one out.
 
<



Tech By Trade

Explorer Addict
Joined
May 2, 2012
Messages
2,535
Reaction score
170
City, State
Your mom's house
Year, Model & Trim Level
07 Sport Trac
try the fuel filter. When it plugs up it starves the 2 far cylinders and causes a misfire. Could be the fuel pump too. Couldn't hurt to check the pressure on the rail.
 
<



SteveOReno

Member
Joined
February 5, 2015
Messages
11
Reaction score
0
Year, Model & Trim Level
2006 Ford Explorer
try the fuel filter. When it plugs up it starves the 2 far cylinders and causes a misfire. Could be the fuel pump too. Couldn't hurt to check the pressure on the rail.
A fuel problem should be consistent and immediate, and it should affect the engine at higher rpms. That does not explain the one hour delay I see when I disconnect the battery. However, I should replace the fuel filter anyway.
 
<



Top