From what diagrams I'm seeing, the PIP( for which that code is saying is malfunctioning) is located in and part of the EEC IV ignition module. This is a metal "box" usually on the fender well. It will have a connector that has 5 or 6 wires. The PIP portion is were only 2 wires apart from the other 3 or 4 go into the module. The wires connect it with the distributer housing. You can take the ignition module in to auto zone or kragen etc..(depending on your area you live). Most will check its function for free.
Trouble code P1320 means: Distributor Signal Interrupt
Trouble code P2300 means: Ignition Coil "A" Primary Control Circuit Low
Trouble code P0351 means: Ignition Coil A Primary/Secondary Circuit
Assuming there are no DTCs (diagnostic trouble codes) I would go back to basic tune-up procedures like spark plugs, ignition wires, distributor cap, distributor rotor and base timing. A check for vacuum leaks also.
Trouble code P0350 means: Ignition Coil Primary/Secondary Circuit
Trouble code P0320 means: Ignition/Distributor Engine Speed Input Circuit
Trouble code P0320 means: Ignition/Distributor Engine Speed Input Circuit
Trouble code P0320 means: Ignition/Distributor Engine Speed Input Circuit
For a few years there, Honda had a problem with the ICM. It's inside the distributor.
Sounds like ignition trouble. Check condition of distributor cap, rotor, ignition wires and spark plugs. Drive thru any large puddles lately? Could also be moisture inside distributor cap.
There are kits available which turn your old points distributor into an electronic ignition system, i have converted both my veedubs and it removes all of the guesswork & trouble from your distributor. The kit comes with instructions and is very easy to use, you basically just gut your distributor cap & put in a circuit board & boom, electronic ignition. I will post a link below. Oh, and gap your plugs at .024 inches.
Diagnostic Trouble Code