I own an Isuzu Trooper II '87, recently it keep accelerated at 20000 or more, soon as it cools, idle speed comes to normal about 10 (X100)…
Behavior is not consistent; we had examined the accelerator cable and mechanism, but look OK to me. The mechanic has not been able to dig into the carburetor but I’m suspecting a failure on it.

When running at high revolutions it just stay accelerated, after some play with accelerator it comes down.

I lack of experience but any suggestion is welcome…
:(