Yeah I realized it was a pretty delicate job. Distributor is original to motor I believe. So the distributor itself is probably pretty shot then?

 

Without seeing the ignition wave pattern on an oscilloscope, there's no way of knowing if the bushings are worn. I usually see them last somewhere between 150K & 200K miles. The OEM distributor has a plastic housing, good quality replacements are aluminum.... much better

 

What would allow it to move slightly twisting clockwise or counterclockwise, if the distributor cap and rotor are both new and appropriately tight?

 

The cap? What brand did you install? Might just be a cheapie. Should be AC Delco It needs to be tight. If it moves, it's not tight.

The distributor? There's a 10mm bolt in the hold down bracket that secures the distributor in position after camshaft retard is adjusted.

 

I'll check it tomorrow and see what I find and reply back with the results. I appreciate all the help.

 

Ok I checked the 10 mm bolt on the bracket and. It was a little loose, I tightened it. Checked scanner at idle...spark advance still hovers between -19 to -23 degrees. At a rev to 3500 rpm it is around -36 degrees. What next?

 

You'll need to have someone check & adjust camshaft retard, and it would be a good idea to do the crankshaft position sensor relearn too. Whenever the distributor hold down is loosened, camshaft retard should at least be checked. If you're planning on replacing the distributor, now would be the time. Let me know if you need the procedure and I can explain a very easy way to do it, and save you a ton of grief.

 

I unhooked the battery for an hour yesterday to reset the computer after I tightened the distributor. I haven't had a chance to run the scanner on it yet, but the RPM surging has pretty much disappeared. I assume the fuel pressure leakdown is still bad though.

 

Disconnecting the battery basically does nothing as far as resetting the PCM. It does not erase any trouble codes, and it certainly doesn't "fix" anything. It will turn off the check engine light, and it will remain off, unless there is a problem present in a circuit that is continuously monitored. Depending on how the PCM was originally programmed, it may or may not reset the readiness monitors, (some do and some don't). If yours resets them, and a monitor fails during its test, the check engine light will come back on. This could take anywhere from a few minutes to a few months before all monitors have run and completed their tests. You really need to make sure the basics are good before continuing: fuel pressure and leakdown, camshaft retard, crankshaft position sensor relearn, and any DTC's that are in memory.