Does a high pressure fuel pump need to be timed?
Unlike mechanical systems these high pressure type pumps do not need to be timed with the engine as the injections timing is controlled by the ECM firing the injectors, and the pressure control valve is controlled by the ECU and varies rail pressure according to load demand.
How do I know if my injection timing is correct?
Turn the engine so that the unit to be checked is toward the TDC of compression stroke (plunger upstroke) so that hair line marking on plunger and pump body are coincided. When hair lines are coincided, stop turning and check the mark on the fly wheel whether timing is correct or not.
What is a high pressure fuel pump?
The high-pressure pump is responsible for compressing the fuel supplied by the electric fuel pump to the pressure required for high-pressure injection up to 20 MPa (200 bar).
How do you adjust the timing on a fuel injector?
If you decide to alter the fuel injection pump, you’ll need to:
- Use a socket wrench on the front camshaft bolt to hand-turn the engine clockwise until the first cylinder is at TDC.
- Both the intake and exhaust valves should be closed, and the TDC mark should be aligned.
What controls a high pressure fuel pump?
This pump is driven off a lobe on the camshaft. This part of the fuel system is called the high-pressure side. The pressure from the high-pressure fuel pump is monitored by the Powertrain Control Module (PCM) through a sensor and can be modulated by changing the volume of fuel entering the pump inlet.
When to remove a high pressure fuel pump?
Note: If the high pressure pump binds when being installed or if there is misalignment in the bolt holes, remove pump and verify timing mark at the twelve O’clock position and reinstall. Ensure the correct bolt length is used when the high pressure pump is installed.
What happens when a Duramax CP4 pump fails?
CLICK HERE to purchase our LML CP4 High Pressure Fuel Pump Failure Kit The 2011-2016 Duramax suffers from a high pressure fuel pump issue unique to this year range. Failure of this CP4 pump is usually catastrophic, causing instant contamination of the entire fuel system with metal particulates.
How can I tell if my CP4 pump is failing?
Remove the CP4 pump and then the fuel pressure regulator for inspection. If the body casing of the pump is cracked, as in the picture, or you find metallic debris on the fuel pressure regulator screen (pictured right) this is indicative of a pump failure.
Is there a timing light on a fuel pump?
The fuel pumps that I have found in views of your engine have 4 independent pressure outlets and so it must be in time. There is actually a timing light to adjust injector timing on such systems.