1992 Yukon 5.7 sensor problems

[ajyukon1427]

I have a 1992 GMC Yukon with a 5.7 and 174k on the clock. Recently I'll be driving in city, with the engine warm, and I start getting a bad miss at all engine speeds... very noticeable loss of power, and the miss happens even at idle. When I park the truck for an hour or so, then drive again, it's fine as if nothing happened.

 

The plugs, wires, cap, coil & rotor have all been replaced within a year, all to try and fix this problem. My obvious question is whether it's the IAC, MAP or TPS sensors, and if so how do I find out which is the culprit? No engine fault code has been tripped.

[grampadirt]

You might want to check out the ignition module in the distributor.