Ford Repair: 1993 Mustang LX 2.3L Check engine light, mustang lx, electronic record

Question
My car keeps taking "spells" that will sometimes last for 2-3 days straight before it will start running good again. It starts with the car shaking and idling rough (feels like it's going to stall), the RPMs will drop from 600 to 300 or less (the car is not really running that slow, but that's what the gauge says),I lose a little horse power (feels like I'm pulling a trailer), and it knocks a little (as if the timing was off a little. The only clue I have is that the problem usually just goes away after the car has been at normal running temp for about 5 minutes (that takes forever, my car has always been cold natured). The car has no "memory" of the event (when hooked up to a tester) and I can't get to my mechanic (or even Advance Auto) in time to test the car to catch what is causing the problem.

Answer
With no electronic record stored, try the fuel filter. That has to help some what. When you get the chance, test the fuel pressure under an idle, and at a high RPM to make sure you don't have a fuel pump issue. Clean the soot out of the throttle body also, believe me, it's there.