Cadillac Repair: Failing ignition control module, fuel pressure regulator, vacuum leaks

Question
I have a '93 Caddy 4.9 with a misfire at idle that gets worse the hotter the engine gets, yet it comes and goes. It is worse the more load on the ngine such as being in drive or having the AC comp on. Plugs are new, wires check OK, cap OK, rotor OK, coil OK, injectors OK. No vacuum leaks. Fuel pressure, fuel pressure regulator OK. Not showing any codes. Other than at idle the car runs great. Can the ignition control module be going into intermittent failure due to heat? I've been up and down just about all the tests from the factory manual with no results.  

Answer
Hi DF Bonnett, You could be right about the module but the injectors are what usually fail as they heat up. There is a special testor that sends current through them like the computor would and then it shows the voltage drop. Otherwise you will need to ohm out each one and see which ones are differant. Bill