It took me a long time to learn it, but for general problems, you go through it this way:
- Basic mechanical condition - adjust valves, vacuum gauge test, check compression
- Ignition - dizzy mech/vac advance & retard working; plugs, wires, points, coil, condenser, cap, rotor, all new or in good condition; plugs gapped to spec; timing and dwell to spec
- Injection - All hoses in place, no air leaks anywhere; all connectors and boots in place; no shorts; fuel pressure to spec; sensor resistances ok; MPS holds vacuum; etc.....
Just doing that stuff will usually get rid of most problems. For more detailed FI analysis, go through Kjell Nelin's procedure here on the PP web site, and check your components using my D-Jet parts web page.