Im trying to figure out how the fuel is delivered on a thrd gen so bear with me please. the way I understand it the injectors are opened electronically so the pump is what controls the pop off pressure. on an older truck changing weak injectors increased milage. On a lot of 06s people are complaining about horrendous milage mine included (13 mpg is great) is there a chance that dodge got some batches of weak cp pumps? has anyone noticed a pattern of lower pressure equaling lower milage? if doesnt make any sense sorry. If I could get some help understanding this I would appreciate it the truck has 45000 miles on it I have posted several milage questions and you guys have been a great help this is just another one

 

The CR IP is simply a high pressure supply pump and has no relationship to or control of the injection event. It simply maintains a constant pressure in the rail as dictated by the ECU.

A CR injector does not pop as a result of IP generated pressure, rather, the injector is fired by allowing high pressure fuel to lift the needle off the seat. This is done by electronically opening a port on the injector to allow the high pressure fuel into the correct area. This all controlled by the ECU not the IP.

Low fuel pressure could contribute to low mpg but it also shows as low power, hard starting, and other issues.

Bosch has had quality control issues since they started building the CR systems and its really hit or miss. While a system may be operating within paramters, that does not mean it is operating at optimum efficiency. This can have a drastic effect on mileage and is one of the main reasons why performance, mileage, etc can vary greatly between trucks.