Air regulator is the thing under the intake manifold. Make sure the BLACK connector goes to it and that there's power. Check engine temperature sensor screwed into the underside of the intake and that the WHITE connector goes to it. They work in tandem. The temp sensor signals the ECM to inject more gas on a cold start. To check it:

"There are two connectors on a bracket just behind the battery. The larger of these two has the 2 wires from the temp sensor in it. They are BLACK and GREEN w)YELLOW stripe on my 88 truck. The way the connectors are mounted on my truck, these two wires are right on the top of the connector. Simply unplug the connector and put your ohmmeter across those two pins (DON'T BEND THE PINS!!!!)." - Troopershere

"degrees F / K ohms
14 / 7-12
50 / 3-5
68 / 2-3
122 / 0.7-1
176 / 0.2-0.4" - pucci

If you changed the throttle position sensor (little black box on the firewall side of the throttle body) you need to reset it:
"The prongs on the switch are labeled top to bottom, I, P and F. With the throttle closed, you should have no continuity between P-F and continuity between I-P. Slightly depressed gives no continuity between both of those sets of prongs and with it fully depressed (WOT), you should have continuity between P-F, but not I-P.
To adjust the switch, hook up the Ohm meter to I-P and place a 0.012 feeler gauge between the throttle stop and the throttle lever. Adjust the gauge until the point where the continuity is just established. Then use a 0.020 feeler gauge to make sure continuity is broken. At that point, it is adjusted." - Michael

Then of course there is the idle air controller on the top of the thermostat housing that's supposed to kick up the idle when the AC is on and the 02 sensor could cause similar symptoms. Don't you love these things? It's like a "Where's Waldo" hunt! I've had plenty of help from this board
(as you can see from the quotes) so welcome back to the best 'Zu info site.