Hello there I been having this doubt about my gauge reading the correct fuel pressure I have been getting 13 psi on WOT I have installed an Airdog 100 and also a brand new Vp44 pump from Bluechip just this pass June. I have checked the pressure with another gauge and I am getting the same reading. Do you thing thats a good pressure reading?

 

its ok it would be brtter with 16 17 check your fuel filters

 

I am no expert, but from what Ive gathered, anything from about 7-10psi at WOT is sufficient.

 

13psi sounds fine. I think there is a shim that you can put in to gain a psi or two.

PSI should be 13.5 +/- 5psi

 

On a VP44 powered truck under no circumstances should you have pressure lower than 11 at WOT. 13 is best.

 

Wyatt, On a factory truck 7-10PSI is fine, but when we start using boxes and such no less than 13 is desired at idle.

 

Not with the OEM under hood lift pump it isn't. Of course that's my opinion having changed both a number of OEM LP's and VP's out.

This is different with in-tank LP's and CP3 powered trucks of course.

 

In tank pumps are by far the worse. And I agree , I wouldnt feel safe but the pump will live at 7-10PSI for 100,000+ miles. With that being said, I feel its more a volume issue that will kill the pumps, Not a pressure issue! We see so many folks come in and say, My pump cant be dead...I had my fuel pressure checked , it was above 14 lbs.
But at WOT, the flow from somthing like the factory carter isnt sufficent and the pressure drops causing lack of lubrication and cooling.

 

Well, I've said thi before and I'll say it again it is mathmatically impossible to have a good flow rate with no pressure. You can't take the square root of "0" which is what you need to do with zero pressure in Bernoulli's principle.

So, establishing a safe pressure of 11 run the equation and get good flow. It's all good.

As you indicate "my pump can't be dead" - oh it most certainly can if the fuel is incased i the vacuum. Break the seal and the truck won't start. Again, I've seen that so many times it isn't funny.

It's a matter of opinion and in my case experience but it is only my opinion and I don't expect everyone to agree with it.

Cheers...

 

I'm not saying I dont agree with you, I'm saying I do agree with you. What I'm saying is a factory truck with factory parts can be fine for years. True, good flow rates are impossible with low pressure but the Carters will pass the fuel decay and volume test no problem at 10 psi. When the demand for fuel increases, Wire tap, Bigger injectors and so on , the fuel use must increase, therefore creating flow issues. A carter cant supply that volume even with upgraded lines. I feel that if the trucks not bombed that 10 PSI is enough to keep the pump "safe", Would i run it? No. But it's been proven in factory circumstances that 7-10 PSI is fine for the pump. The carters show a 3-4PSI (let me know if you've had other results) pressure drop from idle to WOT in a FACTORY truck. Now if it's only holding 7psi at idle and you have a 4psi pressure at WOT that will for sure kill the pump. Modify the truck with a wire tap and injectors and the pressure drop is over 8PSI on the factory carter.... Line size has alot to do with our volume but if the pump cant supply enough fuel, There's no way lines will help!

Does this explain what I was trying to say a little better?

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PS just to make it clear. We dont let ANY trucks we build run UNDER 15PSI