I'll accept the fact that this problem may have no solution. This engine is way on the far side of past it's prime, but with valves adjusted, engine timed it's a tad sluggish off the line and the idle is somewhere in the 400
rpm range. The idle adjust screw on the throttle body is backed out to the max. If I pull off a vac hose on the common chamber the idle speeds up so I'm thinking there's too much gasoline for the air getting through. That would point to the engine temperature sensor. Is there a test for the sensor (short of swapping it out)?

'89 P'up, 2.6 I-Tec, 488,000 miles and done... gone to the great beyond