* Injector Failure: A faulty injector can spray fuel incorrectly, leading to incomplete combustion. This can cause a knocking sound (often described as a pinging or rattling) because the unburnt fuel is detonating in the combustion chamber. Disconnecting the injectors prevents fuel from reaching the cylinders, thus eliminating the knock.
* Possible Causes of Injector Failure: Several things can cause injector failure:
* Clogged Injectors: Buildup of deposits can prevent the injectors from spraying fuel properly.
* Worn Injectors: Over time, injectors wear out and can leak or spray inconsistently.
* Low Fuel Pressure: Insufficient fuel pressure can lead to poor atomization and incomplete combustion.
* Electrical Issues: Though less likely if disconnecting *all* six stops it, a problem with the injector wiring or computer control could also contribute.
* Important Note: Running your engine with injectors disconnected is extremely dangerous. You're depriving the cylinders of fuel, which can cause severe engine damage. Only disconnect injectors for brief diagnostic purposes, and *only if you are certain of the cause.*
What you should do:
1. Do not drive the vehicle. Continued operation with this problem risks catastrophic engine damage.
2. Check your fuel pressure: This requires a fuel pressure gauge and is often best left to a mechanic. Low fuel pressure can affect all injectors.
3. Consult a mechanic: A professional can diagnose the exact cause of the injector problem and repair it safely. They can perform a compression test and a thorough inspection of the fuel system. They can also check for other potential causes of knocking that might be masked by the injector issue. Blindly replacing injectors without proper diagnosis could be a waste of money.
In short, while disconnecting injectors points to a fuel delivery issue, it's crucial to get a professional diagnosis before attempting any repairs. The underlying cause could be more complex than just a bad injector or two.
