Confusing running issues
 

I have a 96 6.5 Turbo, and I have been having issues with it at stoplights. It is like it wants to shut down. I changed the fuel filter and air filter as well as two new batteries due to starting issues. after all was done, it ran great for two days. Yesterday it started stalling worse and shut off and was idoling at about 500RPM. Check engine light came on and pulled a P1656 (Wastegate solenoid control circuit). Today I go out and the light is off and is running fine. I have been told the issue is not in the wastegate, but somewhere else. The fuel pump is turning on but making a super loud clicking. I have heard a lot about the PMD fixing the problem. Is there any suggestions on where I should start?
Thanks everyone!

The wastegate solenoid is a common problem-they wear out.
trace the vacuum line from the wastegate actuator over to the drivers side valve cover where it connects to the wastegate solenoid and check the electrical connection and/or replace the solenoid.

The stalling does not sound like a PMD from your description but could be.
I would be interested to have the results of a timeset command performed by a quality scanner or even the reported desired and actual timing #'s.

I am wondering if you are having a problem with the timing stepper motor,or possibly even a failing fuel shut off solenoid?

---AutoMerged DoublePost---

I would also like you to safely park the truck and while it idles and open the water in fuel drain valve that is mounted near the thermostat housing.

If the truck stalls the LP is not supplying enough fuel and needs further diagnosis.

Before going for expensive parts let's make sure the fuel to IP is being sustained Lift Pumps & OPS operation and troubleshooting