trailblazer 2003

[jimbye4]

braking for a stop sign, engine suddenly for no reason increased to 3500rpm.
very scary so shut engine off. restarted ok.
anyone have this prob?

[maxwedge]

Welcome to AF, foot on brake, engine hit 3500?

[jimbye4]

yes. in drive. local mechanic thinks transmission as nothing shows on dash. eg:no engine check light

[maxwedge]

The idle air control has no capability to force the engine to 3500, something else is going on here.