Ford Repair: 93 Ford f150 s/cab xlt 5.0 liter idling roughly, throttle position sensor, battery gauge

Question
I have changed the idle air control, the egr sensor, the ignition switch, and the fuel filter. When I start the truck, it acts like it can't breath. The idle will go from 300 or so up to 1000, then back down. The exhaust makes a slightly noticeable popping sound sporadically. The battery gauge will also drop to about 8 or 10 when the idle rpm drops. At idle, the entire engine will lurch and shake the entire truck. When I give it gas (in park) at around 3000 rpm it smooths out quite a bit, but the popping sound and hesitation is still there.

Answer
Does it backfire any? At first glance I went for the throttle position sensor. On second glance, I think that you may be looking at a defective cam. You need to do a leak down test to make sure that you're valves are opening and closing properly closing.