fuel rail pressure

[Chris Hester]

i have 03 Silverado w/6.0 ...truck idles fine until you start drivingand try to accelerate then it goes to missing, coughing and sets 0332 code? fuel rail pressure shows to be 50 psi and will drop some at high idle...is it the fuel pump???

[davester]

not sure if '03 is returnless or return fuel system (ie, if there is one fuel line or two running from the tank to the engine).

 

If it is returnless (only 1 line), then yes, it's probably the fuel pump.

 

If it is the earlier return style, then it could be the fuel pressure regulator mounted on the fuel rail, or possibly the fuel filter (on the inside of the frame rail under the driver's seat).

[CamGTP]

2003 is still a return style fuel system.

 

The knock sensor code is kinda unrelated to the fuel pressure issue. The rear sensor hole in the valley always get filled with water and moisture which ruins the sensor. New AC delco sensors and a harness usually fix it.

[Chris Hester]

knock sensors have been replaced, new fuel filter and I just replaced the fuel pump...started the engine and fuel rail setting on 52psi...needless to say I'm a little perpexed to whats going on

[CamGTP]

Any knock sensor code that is pending or current will pull the maximum amount of timing allowed in the calibration. Should be right around 8 degree's of timing. A scan tool would show this timing amount being pulled as well.

 

Even new sensors can be bad or out of spec right out of the box.

 

What does your fuel pressure do under load though. 52 at idle is fine but if you get on the throttle under load orfull throttle and it can't maintain or 52psi that is a problem. It should rise to about 58psi under heavy load.

 

 

A scan tool will also show you if you are having misfires on certain cylinders, would better help see if that is something to look at.

Edited July 21, 2020 by CamGTP

[Chris Hester]

my 03 silverado is still having issues...rough idle, no power under load, will not take throttle and is loading fuel to no. 1 bank...any suggestions where to start looking?

[riverbanks]

What method are you using,relating to rich on bank 1?