After just having a new front caliper replaced today on my ATR I've only driven 1 mile from the garage when the malfunction indicator light came on the dash. This has never come on before. When I pulled up to some nearby traffic lights I noticed the idle was dropping to almost stalling. Wondered if anyone has any idea what it could be?
Malfunction indicator light
- Thread starter bbsheppo
- Start date
I don't know the H22 engine but if they were near the brake fluid reservoir or booster (if replacing fluid) maybe they knocked a vacuum line which is causing the engine to lean out at idle.
As the throttle plate is effectively closed at idle, a vacuum leak has greater potential to bring unmetered air into the engine by other means causing it to stall or run roughly and maybe set a lean code. The engine vacuum remains unchanged behind the closed throttle plate so it will still try and draw air from anywhere, a small hose will do just fine.
As the throttle plate opens during acceleration the unmetered air become negligible as a percentage of the air being drawn in ( as the throttle is fully open) then the air will enter here unrestricted albeit metered and therefore fuelled correctly.
As the throttle plate is effectively closed at idle, a vacuum leak has greater potential to bring unmetered air into the engine by other means causing it to stall or run roughly and maybe set a lean code. The engine vacuum remains unchanged behind the closed throttle plate so it will still try and draw air from anywhere, a small hose will do just fine.
As the throttle plate opens during acceleration the unmetered air become negligible as a percentage of the air being drawn in ( as the throttle is fully open) then the air will enter here unrestricted albeit metered and therefore fuelled correctly.
