Low rail pressure

[LBZ_tom]

My LBZ has low rail pressure, was told to do injector return test and cp3 return test, how do I go about doing both of these? Thanks in advance.

 

[NC-smokinlmm]

You bottle test it yet?

 

[LBZ_tom]

You bottle test it yet?

Not yet, will do today, already has a plug though

 

[Rancelot211]

How many miles are on the truck? Do you have a lift pump?

 

[IdahoRob]

https://airdogliftpumps.com/2019/02/27/duramax-fuel-rail-pressure-is-low-now-what/
A little write up i did that may help.

 

[pjc]

High fuel temps contribute to this. Like long RV pulls up Baker grade at 70mph when it is 114F outside and your fuel cooler is not surrounded by a Transfer-Flow fuel tank.