Hard starting once hot.

[Triple]

My 1995 AWD Safari starts almost instantaneously when cold, but re-starting after the engine has reached normal operating temperature is much more difficult. Idle is also much better upon cold start-up. Idle and throttle response after a hot start are rough for 10-30 seconds while the engine "clears its throat."

This appears to be a common problem, but solutions seem to vary according to year/model because of different injection and ignition systems. Bad ignition control modules, fuel pressure regulators, and coolant temperature sensors all seem to create the same symptoms, so I'd like to know which is the most common failure for my particular year/model.

Receipts from the previous owner indicate the van had a recent tune-up before I bought it. I replaced the air filter and sprayed some Seafoam into the intake, neither of which made any difference.

I'm not getting any warning lights in the dash and I do not have an OBD-1/1.5 scan tool. Trying the jumper-method and counting the flashes yielded no results because no lights illuminate in the first place.