still getting codes!

[MIke713]

been working on my 2006 3.0l ranger had a hesitation.miss since I got it used, 135 K on the clock, codes I am getting now are , PO300, PO316, PO301, PO302 . have changed plugs(motorcraft),wires, coil pack , intake gaskets( to fix a vacuum leakand lean code) water pump, t stat. Checked fuel pressure, cleaned maf new fuel and air filters checked compression 130ish all cylinders. now I am getting the PO172 code Rich condition. what am I missing ? Truck will start right up after sitting over night no problem but after it warms up it starts to hesitate and or shuttwr when at a light or stop. then restarrts you have to crank it and hold the pedal down somewhat.

 

[RonD]

130ish is pretty low for 3.0l, 160ish would be expected

Try redoing test with all spark plugs removed, you need to do this to get good crank speed for true PSI numbers
cold engine test, throttle open(push gas pedal down while cranking for test)
The fact it misses more when warmed up may mean you will need to do a warm engine compression test, but just do the cold test for now

After testing all 6, retest each one again but add a teaspoon of oil to each cylinder, I use a straw, I dip it in a bottle of oil then put finger over the end to hold some oil in the straw as I lift it out and place it in the spark plug hole.

This is a "wet test", compression will always go up with wet test, but the amount it goes up can tell you if rings or valves are leaking more

2004 to 2006 Ranger 3.0l engines had a TSB about recessing exhaust valve seats.
Seems there was a problem with these seats and they would not seal cylinders causing random misfires, P0300/P0316, and specific cylinder misfires, P030X

I posted TSB in this thread #6: http://www.therangerstation.com/forums/showthread.php?t=153497

This might not be your problem, but compression test is either good or bad it can't be "intermittent", so once done it can either confirm a valve issue, so you don't waste money on non-fixes, or show it is not a valve issue and you can find the actual issue

For the Rich issue check the vacuum hose on the Pulse Damper, end of fuel rail on engine, if Damper leaks, raw fuel will be sucked into intake, if vacuum hose has fuel in it or smells of fuel then you will need to replace damper.