Medium and Heavy Trucks
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Hi Rick it's Dan. Thanks for the request. If you have lots of bubbles at your return and you isolated the tank to pump suction lines out of the equation by bypassing with a bucket of fuel, you have injector o rings that have failed and possible injector problems. If these injectors have 500,000 or more on them Cummins recommends they all be replaced. Let me know if you need more help.
Are you getting any fault codes? If so what are they?
Could you get me the fault code numbers that are logged? We can post back and forth as needed. I will be loggin out for the night shortly but we will still be able to follow up as needed.
Sounds good. Let me know
Thanks for the info. Here is the troubleshooting for that fault.
What is your fuel pressure running? Here are the specs.
Fuel Pressure Specs (All Fuel Systems)
Cranking 25 psi
1200 RPM 120 psi
2100 RPM 150-180 psi
check for power at the fuel shutoff solenoid and listen for it to click with the IGN switch on. Check the resistance of the solenoid. The ohms reading from the post to engine ground 6 to 15 ohms for 12-VDC solenoids. Try running a clear hose from the fuel pump inlet fitting from the tank or bucket of fuel and make sure the pump is pulling fuel to the engine and if not the pump s faulty. Let me know
You likely have a faulty check valve. Check the fittings coming out of the FICM ( ECM) cooling plate and there should be a check valve in one of the fittings. A weak pump will also cause this if it is not sucking in air as it seems you already confirmed. Let me know