4.6L 3v Misfiring - Done my research, last resort.

[saefjordan]

Hi guys:

I have the 4.6L 3v in my 2007 Explorer Sport Trac with 89k on the clock.

I am experiencing:
- Rough idle after start
- Poor acceleration/ hesitation through all rpm ranges
- Shuttering/ Jerking under load between 45mph and 60mph (comes and goes)
- the P0300 random misfire code and P0316

I have replaced:
- Thermostat
- Battery
- All Spark Plugs (at 85k)
- All Coil-over-plugs yesterday
- All Ignition wires/harness are intact
- Cleaned the MAF
- Fuel Filter 1 year ago (first change)
- Passenger Side exhaust manifold

- Still need to fix drivers side exhaust manifold


I am really at a loss here and I cannot figure out what the hell would be causing this or where to look next. I have heard the Camshaft Position Sensor may be the culprit but the vehicle still runs. I do not want to bite the bullet and take it in the shop unless I absolutely have to. Any ideas where I should look next?

Thanks.

 

[arco777]

Check fuel pressure? Check your spark plugs too and see what they're indicating, or if any look different from the others.

Also, long shot here, but with the VCT it's sensitive to the right weight of oil for the cam phasers - did you use the recommended oil weight last change?