hoot
08-25-2003, 19:34
August 2003 starts on page 36:
It does a lot of injection system comparisons between the Big Three.
"Understanding Chevy's New Electronic Diesel"
Rail pressure varies between 5000 and 23,200 psi. "If fuel pressure exceeds 27,550 psi, the Fuel Rail pressure relief valve unseats and bounces to maintain fuel pressure at that level."
"If the Fuel Rail Pressure Sensor is removed for any reason, GM procedures call for replacing the sensor with a new one. The soft iron seat will be deformed the first time the new sensor is torqued, and the old sensor might not seal properly if reused."
Remember that was the sensor that gave some of us those nasty fuel leaks.
"If the sensor fails, the ECM defaults to "Limp In Mode" derating the engine and limiting engine speed to 2000 rpm."
Tons of info on sensor operation and some diagnostic procedures.
I like this one:
"My technician at the local high volume CHevy dealer reports very few problems with Duramax engines and the problems that do occur don't seem to repeat themselves."
There's also an in depth explanation of the two stage high pressure fuel pump.
Some fuel line vacuum data:
"Check for restrictions or air leaks in the fuel supply line foor hard starting/low power problems. Zero to 5 inches of mercury supply line vacuum is normal on a running engine. Measurements of 5 to 10 inches indicate the need for a filter change. After 15 inches, performance will degrade dramatically, and more than 20 inches of measured vacuum is enough to starve the engine into a no-start condition."
It does a lot of injection system comparisons between the Big Three.
"Understanding Chevy's New Electronic Diesel"
Rail pressure varies between 5000 and 23,200 psi. "If fuel pressure exceeds 27,550 psi, the Fuel Rail pressure relief valve unseats and bounces to maintain fuel pressure at that level."
"If the Fuel Rail Pressure Sensor is removed for any reason, GM procedures call for replacing the sensor with a new one. The soft iron seat will be deformed the first time the new sensor is torqued, and the old sensor might not seal properly if reused."
Remember that was the sensor that gave some of us those nasty fuel leaks.
"If the sensor fails, the ECM defaults to "Limp In Mode" derating the engine and limiting engine speed to 2000 rpm."
Tons of info on sensor operation and some diagnostic procedures.
I like this one:
"My technician at the local high volume CHevy dealer reports very few problems with Duramax engines and the problems that do occur don't seem to repeat themselves."
There's also an in depth explanation of the two stage high pressure fuel pump.
Some fuel line vacuum data:
"Check for restrictions or air leaks in the fuel supply line foor hard starting/low power problems. Zero to 5 inches of mercury supply line vacuum is normal on a running engine. Measurements of 5 to 10 inches indicate the need for a filter change. After 15 inches, performance will degrade dramatically, and more than 20 inches of measured vacuum is enough to starve the engine into a no-start condition."