What causes the Mitsubishi Pajero V73 to stall when braking due to low idle speed?
3 Answers
There are many reasons why the Pajero may stall easily at idle, such as air intake system leaks, excessive carbon buildup in the throttle body, low fuel pressure, clogged air filter, fuel injector spray pattern issues or leaks, improper idle adjustment, faulty spark plugs, or malfunctioning mass airflow sensor. Idle port clogging: When experiencing unstable engine idle, first adjust the idle speed. If the issue persists after adjustment, check whether the idle jet and idle air jet are clogged. If clogged, clean with gasoline or acetone and blow through with compressed air. Intake system leaks: If the jets are not clogged, stabilize the engine at a constant RPM and listen for leaks at the intake manifold or carburetor gasket areas. If leaks are detected, resolve by tightening screws or adjusting gasket thickness.
I've been driving the Pajero V73 for many years and have encountered the issue of the engine stalling due to low idle speed when braking. There are quite a few reasons for this. The main one is a fault in the idle speed control system, such as carbon buildup jamming the idle motor, leading to insufficient air intake. When braking, the vacuum booster pump needs to draw vacuum from the engine. If there's a leak in the booster system or the vacuum hose is blocked, the engine load suddenly increases, making it prone to stalling. Problems with the air flow sensor can also lead to inaccurate readings, misjudging the air intake demand; a faulty throttle position sensor can prevent the ECU from properly adjusting the idle speed. Additionally, worn-out spark plugs causing weak ignition or clogged fuel injectors leading to uneven fuel supply can make the idle speed unstable. I recommend first checking whether the idle motor and vacuum hoses are clean and intact. Address any issues early to avoid breakdowns on the road that could affect safety.
My Pajero V73 had this issue before - it would stall when I hit the brakes, especially in traffic jams which was really frustrating. At first I thought it was a brake problem, but the mechanic said it was caused by low idle speed, likely due to vacuum system issues. If there's air leakage in the brake vacuum booster or the pump is faulty, it puts extra load on the engine, making idle unstable and prone to stalling. Also, if the idle control valve accumulates too much dust, it affects air intake control. Last time I just cleaned the pipes and the valve myself, and it improved significantly. Remember to regularly check if your idle stays around 700 RPM - be alert if it drops lower. Periodic cleaning of these small components can prevent problems and save you from roadside embarrassments.
