My engine on the Accord EX 92 act weird after running "hot", the RPM just keep moving up and down between 1000rpm to 1500rpm whenever I break at trafic light, but if I release the break then it's OK. This only happend after running the car for over 20 minutes, before that, engine cool I guess? nothing like mention happend. Would it be the Idle control sensor or someone mention to me it's the break master cylinder. Any suggestion please? Thank you