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Discussion Starter · #1 ·
hey fellas I have a 95 CTD in a 94 f350, the motor is built but my question is that my fuel pressure gauge bounces all over the place is this correct?

when I got the motor is was stock and it ran good, then before i dropped it into the ford i had to turn the motor up a bit....
 

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hey fellas I have a 95 CTD in a 94 f350, the motor is built but my question is that my fuel pressure gauge bounces all over the place is this correct?

when I got the motor is was stock and it ran good, then before i dropped it into the ford i had to turn the motor up a bit....
could be as simple as a air leak, or when you turned it up a bit it could have done in an already failing lift pump
 

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Your Pressure should always stay close to the same. I would see if you can find a leak in the line.
 

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Mine bounced on my 96 till i put a needle valve in my guage line. pretty much solved the problem for me.
 

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them 12V's are notorious for air leeks
 

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Discussion Starter · #7 ·
im running duel fuel pumps also, would that have anything to do with it?

I am having injector problems also, could that possibly be it? I have the injectors getting cleaned and pop tested so im hoping that is the problem.
 

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The LP on the 12valves is mechanical, it pumps fuel in pulses. You need a snubber of some sort to get accurate readings (a needle valve works)
 

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Discussion Starter · #9 ·
The LP on the 12valves is mechanical, it pumps fuel in pulses. You need a snubber of some sort to get accurate readings (a needle valve works)

I have an autometer gauge inside the engine bay. What do you mean by a snubber?
 

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Needle valve installed on injection pump inlet banjo bolt below. If you don't use something to snub the lift pump pulsations besides not being able to read the gauge it will destroy it in short order.
 

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How does a needle valve smooth out the pulses?
 

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You only open the valve enough to read the gauge (have someone watch the gauge as you slowly open it) The valve restricts the flow enough that the pressure pulses bottleneck into the valve and dissapate. Yet enough flow is allowed that the gauge still reads.
 

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Discussion Starter · #15 ·
while the motor is running without the gauge properly installed it bounces between 40-70
 
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