Lift Pump Pressure Question

[KeithW75]

I am using my 50 psi boost guage to measure my fuel pressure so I don't know how accurate that is. I tested mine though and it showed about 6psi at idle and when running 75 down the highway it hovered around 2 psi. I replaced it and put in larger fuel line at the same time and used the aeroquip fittings. After that It still only showed about 9 psi at idle and about 4 psi at 75. What is everyones thoughts on this??? Should I try replacing it again or not worry about it? It drops to zero if I step on it hard.

Modifications include RV ECM, DDIIIs and PMax 2

 

[Ladders]

I would see if you got the new part # thats posted in another thread. If not I would look for an exchange for the one you have to the new #. Dont have the post avail but was would be found in the last 5 days list (I read it the other day and I have to dig it up for my change).

SOTSU!!
\\BF//

EDIT: PS the thread is about: New lift pump a performance item. The quoted part #: "By the way, the part number is # 3938435. "

[This message has been edited by Ben Stair (edited 05-15-2001). ]

 

[EMDDIESEL]

If i heard you correctly, you are using your 50PSI BOOST GAUGE to check your fuel pressure?. If that is what you in fact are doing and it is a mechanical gauge, you are risking a serious mess in your interior of your Ram, or worse. Boost gauges have internal diaphrams that are NOT desinged for liquids, let alone fuels. It does not matter that it can hold 50psi, thats 50 psi AIR pressure, not liquids. I once saw an oil pressure gauge rupture, it was not pretty

 

[Mopar-muscle]

EMD is correct , not only should you use a gauge designed for fuel pressure testing , you may need to get a new boost gauge now . those readings sound lo to me , i would suspect the incorrect application of the gauge used .

 

[KeithW75]

Well, I don't leave it there for long I just hooked it up for a short time to see what the pressure reading was.