1988 F150 5.0 L with an automatic transmission. 160,000 miles. There appears to be no vacuum leak and the IAC checks out okay with an OHM meter. Can these valves still be bad if the ohms fall within the parameters? Once the truck is warmed up the hard start problem virtually disappears. No surging idle and the problem will go away if I put the truck into gear immediately after start up. I read something about leaky fuel injectors. Could this be causing the problem, too? Any advice on where to start will be appreciated. This issue came up almost without warning.