Fuel pressure problems

[Moparbuckeye]

Just installed my Glowshift fuel pressure gauge, and everything is ok at idle. When the truck is at idle it reads right around 15 psi. My problem is that when driving down the road it spikes from 10 to 20, it will stay constant at about 15 psi for a few miles then it will drop to around 10 and quickly spike to 20 then drop back down to around 15. I have the snubber valve installed as per the instructions, the only thing i did different was install the sending unit at the injection pump instead of the at the lift pump. Anyone have any ideas as to what might be the problem???

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[Polaraco]

Let's have some more background.
How many miles on the truck? What weight oil? When was the last filter change?

Even 20 PSI is too low. . . I'm inclined to think you have a bad check spring in the oil pump or the pump is getting ready to crap. Excessive bearing wear is the only other cause for low oil pressure I can think of. The spiking is curious.

Define what a snubber is for me. I want to make sure we are thinking of the same thing

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[Moparbuckeye]

Fuel pressure...... not oil pressure.

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[Polaraco]

I'm an idiot. . . LOL I read it wrong, but then again, you don't know what my medical history is.

Anyway, fuel pressure is going to jump all over the place. I forget what the minimum is on the pump, but the common rail is 11. Mine jumps all over too with the CP3. I found my pressure to stay higher (16) while cruising at highway. It's all over the place in lower speeds and gears. I think it has to do with how the pump takes fuel.

I say it's normal, but I could be wrong

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