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Good morning, have you replaced the camshaft position sensor?
It could be a short in one of the sensors. I do not have any of the books to help walk you through testing so I am going to opt out and hope one of the heavy duty techs have access to the diagrams.
Hi McCoy, My name is***** see you have installed a used ECM. Was the ECM reflashed with the most current software updates or is it still the original programming?
What is the complete model and engine serial number from the ID tag?
Thanks for the update. Do you have the model as it is listed on the ID tag?
complete engine model I mean
What injection pump is on this truck? Is it a CAPS pump?
Thanks for the information. First check and verify there is no restrictions or leaks between the fuel tank and pump that would caus the system to suck in air. Also check the fuel transfer/lift pump is supplying the VP44 pump and you have good fuel supply to the pump. Install a clear hose to watch for air bubbles on the suction side and the return side of the system. Excessive air bubbles on the suction indicate one of the problems I listed. You can also try running the suction and return into a separate reservoir to see if the problem exists. Let me know what fault codes you have logged in the ECM
Click on this link for a great publication for extra FYI on this style pump and system to assist in troubleshooting. I will get you a diagram as well.
As part of troubleshooting installing the clear hose will tell us if there are bubbles there is a supply problem. If that checks out okay then your problem is electrical if it shuts off instantly like turning off the key. Click this link and see page two on how the VP44 relay ties into the system. Have you swapped relays? Check the relay and the powers and grounds. Here are the diagrams to help. Inspect the wiring and VP44 relay. Let me know.
what fault codes is it throwing?
What fault codes are logged in the ECM when plugged in with a scan tool?
Eiter the ECM is shutting down for low coolant or another reason but there would be a code thrown if it is a shutdown. If no then the ECM circuit board likely has a problem such as a bad solder joint etc and effected by temperature meaning the ECM is the problem.
Make sure all your power and grounds for the ECM are good, clean, tight and there is no corrosion or damage in any of the connectors. Have him use the diagrams to identify which pins to test with his volt/OHM meter. also see if you can get a hold of a scan tool to see if the scan tool will read the ECM and pull the codes. I am heading out for the afternoon but I will see any replies on my next available login. Let me know