Saturday, June 11, 2011

Rough Idle Toyota Vios: Vacuum Leak, ISCV, Throttle Body Cleaning, Oxygen Sensor or Brake Booster?

My dear toyota vios 1.5g, codename Sakura, is acting up lately wherever I apply the brakes until I shift to neutral

This only began last month when RPM on my tachometer drops to around 500 from the usual 700 RPM, engine shivers and the hood vibrates to the point of stalling but the RPM immediately recovers to 700.

I thought it's a leaking brake booster at first due to a Google search of symptoms and solutions but ruled it out since it's an intermittent problem not related to the brakes, even the air-conditioning unit is suspect.

First, I'll try a DIY throttle body cleaning using carburator cleaner (i'll have to buy one) then observe then also clean the ISCV (idle speed control valve, or IACV idle air control valve in some systems, servo for others), then have all hoses, valves and gaskets checked for leaks.

It's quite scary at times since I dread the day i stall in the middle of EDSA to be towed by MMDA and get a PhP1500 fine besides the scary "wrecker" experience.

Symptoms and solutions to follow once I solve it. :P


  1. you have solution?

  2. fixed already: engine mounts/support broken rubber causing the vibration