fuel pressure gauge

[mrclean]

I'm wanting to hook up my fuel pressure gauge....finally. I have a FASS installed, with the supply line going directly to the VP, so the factory fuel filter can is gone. I do have a T-fitting I could use by cutting the hose (don't really want to do that), but I had hoped I could use fittings of some sort to plumb into one of the fittings on the injection pump......is that possible? And if so, does anyone know which fittings I'd need?

[Lone Watie]

I don't know the size, but there is some sort of 90 degree elbow I'm using right at the VP inlet that is tapped for 1/8 in pipe threads which is where my FP gauge is hooked up to. You should be able to do this no problem. It is a 90º banjo bolt I believe with the 1/8 in threads tapped into the opposite of the elbow. Call Vulcan Performance, they should be able to help you out or visit the website: http://www.vulcanperformance.com They have a large variety of fittings. I'll do some research right now to see if I can find it, it's where I got mine. Here you go, I think this is what I used - it's a tapped banjo bolt with 1/8" NPT, it wasn't an elbow but straight. http://www.vulcanperformance.com/Tapped-Banjo-Bolt-p/tbb.htm

[dripley]

There is nothing wrong with cutting the tee into the fuel line.I ran my fuel line thru the oe canister and this is tapped in between the canister and the vp. The needle valve you see is there for dampening the pulses from the vp. It is barely open, just enough to get a pressure reading. 'The pulses will beat your pressure gauge to death very quickly. I got all of this from Vulcan also. I also eliminated all of the banjo bolts with larger fittings for better fuel flow. I would think the fitting that came with the Fass you used on the vp is probably larger than the standard banjo bolt.

[Lone Watie]

There is nothing wrong with cutting the tee into the fuel line.[ATTACH=CONFIG]5446[/ATTACH]I ran my fuel line thru the oe canister and this is tapped in between the canister and the vp. The needle valve you see is there for dampening the pulses from the vp. It is barely open, just enough to get a pressure reading. 'The pulses will beat your pressure gauge to death very quickly. I got all of this from Vulcan also. I also eliminated all of the banjo bolts with larger fittings for better fuel flow. I would think the fitting that came with the Fass you used on the vp is probably larger than the standard banjo bolt.

The inlet for the VP is 12mm, though, so sooner or later something at 12mm is going to have to be plumbed into the VP. I'm running the 3/8 in kit from vulcan from my filter to the fitting referenced above into the VP.

[mrclean]

Thanks for the link Lone Watie. Does that piece replace the banjo bolt that is next to the VP's inlet port?

[Lone Watie]

There are 2 banjo fittings at the front of the vp, one is the inlet, the other is the overflow valve, to which the return from the VP is attached. The one furthest most to the front is the overflow, the one aft of that, towards the rear, or right in the picture, of the truck is the inlet from your FASS/AirDog/Stock Filter,whichever you have. Here's a pic mopar man has posted in the articles section of the forum. The left of the pic is the front of the VP as looking at it from the left side of the engine compartment. Right side is to the rear of the truck. Hope this helps. And, to answer your question, yes, that piece replaces the banjo fitting in the pic. The only difference is the the fitting from vulcan (I believe Geno's has that part as well see this link http://www.genosgarage.com/BANJO-BOLT-TAPPED-985-09-59L-67L/productinfo/BF%2DLONG%2DTAPPED/) is extended so that it can be tapped for the 1/8" NPT for your FP gauge. I used the 3/8" line kit from vulcan to go from the stock filter to the VP inlet, and added that so I could attach my FP gauge line there as well. You should be good. Hopefully, if I'm wrong, others will chime in on this. Other than the FASS, our VPs should be the same. I'm a 1999 as well. By the way, Richard at Glacier Diesel, from whom I got my fuel boss, mentioned yesterday to me, as a side note, that the overflow valve has been known to cause erratic pressure readings when it starts getting weak. I don't know the internal make up of that overflow valve. Geno's sells that as well for something around $36 and is as easy to replace as the banjo fitting we're discussing. I'm going to order one from Geno's to have in the toolbox if needed. Here's a link for that as well http://www.genosgarage.com/BOSCH-VP44-FUEL-OVERFLOW-VALVE-985-02-24V/productinfo/1467445003/

[Rogan]

in the above pic, I put my FP gauge's snubber bolt in #3 spot, on my 24v.

[Mopar1973Man]

Remember the closer you are to the injection pump the stronger the water hammer pulses are and more damage you'll do to a pressure gauge.

[mrclean]

Remember the closer you are to the injection pump the stronger the water hammer pulses are and more damage you'll do to a pressure gauge.

Yes, I'll be using an isolator and one of those needle valves. Thanks for the info guys!

[Lone Watie]

My isolator is going on 3 years now, and I have it isolated as well from rubbing against anything under the hood, and my FP has been verified with a test gauge. Also using a needle valve on it. I just wanted post-filter pressure for dirty filter indications. I guess I could have plumbed in a tee right after the filter and achieved the same effect. I might do that just for ease of getting to the gauge connection. Down on the VP inlet is a little tight with all the other hoses and lines down there.

[mrclean]

There are 2 banjo fittings at the front of the vp, one is the inlet, the other is the overflow valve

Is the overflow valve actually required? I have a tapped 14mm banjo bolt that I believe would fit(the overflow valve is larger than the 12mm fuel inlet). If I can't use that port, I'll just cut the FASS fuel line and install the t-fitting........

[Lone Watie]

The overflow valve I'm referring to is not plumbed for anything other than over flow for the VP. When the pressure for the VP is too much the overflow valve opens and releases fuel back to the tank. It's not part of the inlet side of things, but the VP outlet. I wouldn't mess with it. I was just referring to it to show you where it is located in relation to the VP inlet connection, which is where my fitting with a needle valve going to my gauge is located. Sorry if I caused any confusion with this.Interesting about the 14mm threads. I had just assumed it would be 12mm like the inlet banjo. I just went and checked my spare overflow I have in my toolbox and sure enough mine is 14mm as well. Apologize for unintentionally misleading you on the size of that overflow. Still, it is not part of the inlet side of the VP though they are next to each other. If you plumb your gauge into there you'll be reading return pressure from the VP to the tank, and will not have overflow protection for the VP if you remove that valve. Hopefully someone can chime in here soon on this to either confirm or deny my understanding of the overflow valve.

[dripley]

Lone Watie is right. You should be reading your pressure up stream of your filters. I have mine plumbed into the line between the fuel filter canister and the vp. I chose to keep my oe canister in the system for the fuel heater and the water in fuel sensor. A little extra filtration does not hurt either. It is not absolutely necessary, just what i wanted. Dont mess with the overflow it should remain and the pressure reading there would do you no good.you can ignore the second picture. got it on there and could not get it off.

[Mopar1973Man]

Water hammer is a big issue for either mechanical or electric fuel pressure gauges. As long as the gauge or sender is hooked up after the last filter and back away from the VP44 it should last a long time. Big the Bosch VP44 injection pump is the source of the water hammer pulses.