Wes,

Check all 4 screws holding the isolator together, and of course the fitting for fuel in and out. There shouldn't be any leaks if everything is tight.

Mark @ DPPI

 

In pic all the screws should be going the same direction being only one half of the iso has threads. The bottom screws (looking at the pic in my gallery) were threaded in from the front. I noticed this before I got it running so I dont know if it would have leaked or not. but better safe than sorry.

 

Your first setup with the needle valve is the best way to go, isolators are a total waste of money.
It sounds like you had the valve open too far.

 

99 cummins can you explain how you have your gauge held down or mounted?Bolted,clamped or duct taped?
thanks tony3542

 

Hey Tony,
Here is the way I have my two gauges set up.


Click on picture for larger view.

 

Hey Tony I just used about a 4" peice of strapping metal and two short self tapping screws and ran the the bottom side of the hood where it wouldn't go through. real easy to do. I'l see if I can figure out how to put a picture on here, if you don't see it within the next hour or so I wasn't smart enough.

 

I think the best place to tap into fuel is the bottom of the fuel filter with a tapped banjo bolt. It also lets you keep the test port at the vp-44 to make a verification reading if necessary. I ran a isspro mech. guage with needle valve and ss/braided line. I was getting vibrations even with the needle valve almost closed. I added a 2 foot piece of fuel/hydraulic line to use as a snubber which solved all vibrations. I also was able to re-open up the needle valve.

 

I added pictures to my photo gallery but they are to small to see very well, if these don't show you what you want let me know and I will PM the larger shots.

 

From what I have found out ....the VP44 is not the reason that the fuel pressure gauges is getting pounded..The 44 does not push fuel backwards...when you have a lift pump trying to push fuel forwards. Here is the reason that I am saying this..
The fuel pressure gauge that is in my wifes truck would rattle so bad when the needle valve was open too much. But it does not make a sound since I did the FASS system and got rid of the stock lp. The connection to the gauge has not changed and I have not had to mess with the needle valve in a year.
I have had a couple of customers experience the same thing..Its not the 44 killing the gauges...its that stupid lp...

Rick

 

I agree. You can confirm this for yourself by noticing that the gauge rattle does NOT change with RPM, like it would if it was the VP causing the rattling.

I got rid of my gauge rattle by using two grease gun hoses (18") and a needle valve. ONe GG hose is right at the VP. The other is right at the gauge. The needle valve is plumbed in between the first GG hose and the -6AN line that feeds the gauge.

The presence of the extra GG hose with the needle valve seems to eliminate all rattline. I think the extra restriction (the GG hose has somewhat small orifices) of the second GG hose damps out the vibes.

It helps to have a stronger, industrial-type FP gauge. While my Pyro and Boost are Autometer units, my FP is a Hewitt industrial gauge from Enterprise.

H

 

You think a Dipricol plumbed into the isolator plumbed to the VP44 will have these "vibration" problems or does that line from the isolator to the VP44 from geno's solve the "vibration" problem?

 

I turned the two screws facing the wrong way around and put everything back together. Now all four screws are tight and working to hold the two halves together like they should. I haven't had a chance to test it to see if it's leaking yet but just sitting idling there is no air in the lines yet like there was originally. I'll know tommorow if it's fixed or not.

 

Forgot to add, my gauge readings are about 1-2psi lower than with no isolator. Does this mean there is still air in the lines or is this normal?

 

How 'bout this...

 

http://www.turbodieselregister.com/u...=20897&width=0

This is a link to the pic of the back of my Isspro mechanical FP gauge. That little pin-hole is really small and limits the amount of fuel to the guage. I have no rattling or any irregularities with my readings. It is steady and smooth all the time. No needle valve, yet, I will get one for safety reasons. The gauge came this way and is why I highly recommend Isspro fuel gauges. The insert could be removed with only a small screwdriver if it needed to be a different size.

I now have a $5 18" grease gun hose hooked to a standard black boost tubing kit which goes directly to the gauge. Quite cheap.

Edit: By the way, with the Vulcan big line kit, my original lift pump cannot be pulled below 10 psi at WOT. I won't post how little it cost.