Why does my car not start with a bad injector?
Start the engine. If it starts easier and the exhaust is cleaner, you have found the faulty injector. If the engine will not start at all, it is most likely due to a badly leaking fuel injector causing low fuel pressure. If the engine starts, it is an indication of a bad injector.
What happens when a diesel injector fails to close?
Over time, diesel fuel injectors wear out and fail to close completely. When this happens they cause a leak-down, resulting in a reduction of fuel pressure across the fuel rail. This can cause a difficult- or no-start condition as well as a smokey exhaust. Too much fuel will also flood a cylinder, effectively reducing …
How do you know when to replace a fuel injector?
Another effective test is to measure the pressure loss in the fuel rail when each injector is fired and pulses for a set period of time. Use an electronic injector pulse tester for this. As each injector is energized, a fuel pressure gauge is observed to monitor the drop in fuel pressure.
What to do if your diesel injector is running dry?
Use a wrench to loosen and remove the connector from the feed tube. Install the fuel feed block cap on the fuel line to shut off the fuel. Do not run the engine long with the fuel line disconnected or it will ruin the injector, which is now running dry. Start the engine.
What happens if you don’t change the fuel injector?
For port fuel applications, not changing the oil can result in blowby and a compromised PCV system, which builds up contaminates on the tip of the injector. Not changing the oil in an engine with direct fuel injection can result in a worn fuel pump camshaft lobe.
When do you Know Your diesel engine injector is bad?
If the Cummins engine won’t run at all, then the injector is usually cracked so badly that the fuel system can never reach the threshold. The oil will also be heavily diluted with diesel fuel. By installing the cap on each cylinder one at a time, the bad injector can be isolated — you’ll know you’ve found it when the engine fires normal and fast.
Why do fuel injectors lean out when under boost?
When the engine is under boost and at a higher rpm, it needs all the fuel the injectors can deliver. If the injectors are dirty and can’t keep up with the engine’s demands, the fuel mixture will lean out, causing detonation to occur. The leaning out may cause higher than normal exhaust temperatures and turbo failure.
When to do a cylinder balance test with a bad injector?
Failed Balance Tests If you suspect that an injector is clogged or malfunctioning, an injector balance test can isolate the bad injector. Scan tools that can disable injectors can isolate an injector for diagnostics. Engine rpm drop may not be an effective diagnostic method when performing a cylinder balance test where an injector is disabled.