I have a 1999 ram 2500 diesel, on a trip to Canada I noticed that it was loosing power. Also on the home leg of our trip the boost pump lost pressure, did not get below 5psi, I changed it and now the pressure is 15 psi. However boost is only 3-4 psi and exhaust gas temp is around 800 degrees F. I checked the waste gate OK, looked at the blower, no oil and not an excess amount of shaft play, also checked for boost leaks, none to be found. Could this problem be the MAP sensor or should I look elsewhere?

 

Could your fuel be jelling in the filter, try some additive in the fuel, do you read fuel pressure at the filter or the VP44. Pressure doesn't always mean volume.