My boyfriend has a 1991 acura integra, it newly started revi

what is the cause of that, help, thank u

a vacuum lieak will do that to your car. Do you hear any hissing coming from the engine? If so check all vacuum hoses and connections for a break. it shouldnt be too hard to find because it must be a big leak to increase therpm that much.

it may be the idle control valve or the O2 senser both will have ur car idle up and down or idle really high like 3000rpm plus.