FCS4Hittman

After sea foam, tuning timing and tps, when warm, the car holds a idle pretty well it wanders a bit but not dying. Now when the engine cools down a little it won't hold an idle until it gets to full temp again I can see that the fast idle cam plunger is being sucked in but it dies still. Tps checked, timing checked, compression checked (80 psi front 75psi back), and tune up. Plus sea foamed 4oz in vacuum off break booster and 12oz in tank . propane didn't yeild results when warm. anyone can point me where to go next? Intake manifold has build up maybe?