Those are the right plugs. Sorry, I have a theory for diagnosis where I look for the simplest cause that has been overlooked.
On that PCV line, low idle conditions are caused by the PCV collapsing under idle. Like AMC wrote, it most likely occurs at the elbow where the vacuum line enters the intake. Ford makes an insulated replacement that is supposed to prevent this problem.
Alternator problems are a big deal for this car. There are issues with the VR plug-in connector similar to the coil problems, and issues with the wiring leaving that connector being either melted in the harness or broken. Intermittent shorts are possible. We also have experienced weak VRs in most rebuilds inspiring me to recommend that everyone seek out a local rebuilder because the business model for those guys encourages the use of better parts. You can check your alternator output using the electronic odometer test mode while you drive the car. Simply press and hold the trip reset button with the key off, then turn the key on, and continue to hold. The odo display will change to read [test], and you can release the reset button. Now each time you press and release the odo reset button you will scroll through one of about 30 test functions. You are looking for the one that reads [bat 12.1] which is what is should read with your battery reading 12.3v at the terminals. I've noticed a .2v difference in mine, but you can't ride around under the hood with a multi-meter on the battery. There is also a FP readout that will give you fuel pressure, but it might display in KPas instead of PSI. The temp readout is definitely in C instead of F. The DTC code display doesn't work very well, and should be ignored. You should also remember that this readout is dependent on sensors, for example, some people who have bad temp sensors will have the readout jumping around and showing ridiculous temps like 200C, but you check it with an infrared thermometer and get nothing close to that. The same would go for a fuel sensor- if it was bad, then it might give bad readings back that you could double check with a mechanical gauge installed in the fuel line.
I think your problem is eventually going to end up being more simple than that, but your level of frustration might go over the moon before then.
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Originally Posted by the user formerly known as ZX3_Chick
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