Different trucks, different rail pressures...?

[trik396]

My truck idles at about 4500psi. I've read of a few other guys having similar readings, but most I've read seem to have 6000-7000psi at idle. My question is, do machining differences in the cp3 cause these variations or is it something else?

btw- my truck runs great, pulls hard, and is making more that the power in my sig currently.

[sootman]

My truck idles at about 4500psi. I've read of a few other guys having similar readings, but most I've read seem to have 6000-7000psi at idle. My question is, do machining differences in the cp3 cause these variations or is it something else?

btw- my truck runs great, pulls hard, and is making more that the power in my sig currently.
Your truck is fine. It is probably just your tuning. Is your FCA modded? Worry about the psi at WOT. Most trucks with stock FCA idle where yours is idling.$.02

[lmills]

03-04 trucks idle around 5600 PSI. 04.5 and ups are around 6600-6800 PSI usually.

[trik396]

Mine idles the same whether I go totally back to stock programming/no boxes or not. Just found that a bit strange...

Thanks anyway...

[Billyram]

I wouldn't worry too much about rail pressure at idle. Lower pressure seems to be quieter at idle. Mine stock was at 6900 psi at idle and now with Smarty 4.4 9000 psi. with a lot more rattle. Running after market injectors some folks don't see as much peak pressure.

[JustinR]

I wouldn't worry too much about rail pressure at idle. Lower pressure seems to be quieter at idle. Mine stock was at 6900 psi at idle and now with Smarty 4.4 9000 psi. with a lot more rattle. Running after market injectors some folks don't see as much peak pressure.

That's weird. The rattle on mine is completely gone with 4.4. Idles at 9000-9500psi and it's much quieter and smoother.

[trik396]

Thanks for all the replies. There are so many variables from truck to truck. Just seems strange that from truck to truck you can see as much as a 3000psi difference STOCK in idle rail pressure. Maybe I should only compare 05' with stock cp3's and sticks for a better picture...?

[Billyram]

That's weird. The rattle on mine is completely gone with 4.4. Idles at 9000-9500psi and it's much quieter and smoother.
Mine idles very smooth with 4.4 and II injectors but has that diesel sound.

[wap]

That's weird. The rattle on mine is completely gone with 4.4. Idles at 9000-9500psi and it's much quieter and smoother.


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