As the title states, I have an intermittent misfire on #6, at idle. The ODBII code is P0306, which has been the same every time this misfire has returned. When the engine is under load, the misfire is gone.

I have replaced the entire ignition set (coil pack, plugs and wires) with OEM equipment, the PCV, and filters. The MAF and TB have been cleaned, and I replaced the IAC, as well as the (infamous) PCV elbow. There are no vacuum leaks that I (or my starter fluid) can detect.

(Is there a way to get rid of the PCV, by chance? It's a big fat PITA...)

To date, that damned misfire returns, over and and over.

What is ironic is that it happens most often when the fuel level starts to get low, typically around 1/8 of a tank, though this last time, it started at a 1/2 tank. It does not always happen, however, hence the 'intermittent' part. Some weeks, all is perfect, others..not so much.

Does anybody have any sort of idea what the dealio is?
I'm starting to think fuel injector, but I'm not so sure.

Help?

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Illegitimati Non Carborundum!
(Don't let the bastards grind you down!)
2003 Edge x-cab, 3.0FFV, 5R44E, RW, 4.10 gears

Try changing your fuel filter and running a can of Seafoam or a additive through your gas tank. You could have a clogged injector and the new filter won't hurt either. As far as getting rid of your PCV, the answer is no. (That is if you want a functional vehicle.)

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Red 2001 Ford Ranger 3.0L XLT, Mods: Throttle Cable Mod, Composite Manifold Conversion, 67mm Throttle Body, Exhaust Dumped behind Cats, EGR Delete, MAF Mount, Electric Fan Swap, Super Chips Tuner, Transmission Cooler, Overhead console, V-Line V713 Sledge 16" Rims w/ PIRELLI Scorpion ATR's, Chrome Surestep Bumper, DUAL 550BT Receiver w/ Bluetooth, 12" Pioneer & 10" Sony Xplod Stacked Truck Boxes with 1200watt BOSS Amp, Optima Yellow Top, Painted Radio Bezel, OHC, and Door Handles.

Just realized I had not given any follow-up on what was found, so here goes..

I ran a can of seafoam through the system, then changed the fuel filter, thinking that at least that would be taken care of.

Turns out, that was all that was needed.

Huzzah for simple fixes

__________________
Illegitimati Non Carborundum!
(Don't let the bastards grind you down!)
2003 Edge x-cab, 3.0FFV, 5R44E, RW, 4.10 gears

Haha nice job bud.

--1993 ford ranger ext cab 3.0 v6--

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1993 ford ranger 3.0 v6

*Sigh*
Dammit, I spoke too soon.
The truck went for about a month or so, and the same damn misfire has returned, as of yesterday. the CEL hasn't popped yet, but that same stumble is evident, and I pulled the P0306 'pending' code.

I'm starting to think at this point, that my #6 injector is failing and it's time for a swap.

If that isn't it..I'm at my wits end. I've covered all the usual culprits, vacuum leaks, new plugs/wires and coil pack. The compression checks out across the board at 150+/- 2, I've cleaned the MAF, and replaced the IAC.

In replacing the injector, can the O-rings that seal the intake plenum be re-used, or should I go with my usual practice of replacing them outright?

__________________
Illegitimati Non Carborundum!
(Don't let the bastards grind you down!)
2003 Edge x-cab, 3.0FFV, 5R44E, RW, 4.10 gears

Definitely replace the o rings. You might not need to but why not.