4AGE 16V engine overheat when at high speed

[chenfon]

another issue come out after she come alive, during idle the engine seem minor shake and sound like 1 sparkplug not work. but all OK when i check 1 by 1 plug by direct pull out during idle. Possible TBody dirty? or the "Idle thermostat" below TBody dirty? due during cold start, the RPM beautiful at 850rpm (with minor shake) but after drive few minute and stop at idle, the RPM will at 1100rpm with non stop up and down (100rpm). wonder what will cause this other then TB? please do advise. tq

Above issue done. after check vacuum on the system found the hose from manifold to fuel pressure regulator minor crack (leakage).

and also found that 1 of my "fuel injector plug" plastic aging crack and connection not good. any of yours replace before on it? pricing wise? tqvm