kkime

I just ordered a digital fuel pressure gauge to install on my 2006 Dodge 2500 mega cab 5.9 and not sure on how to install it, I also got a snubber valve that I was told I had to order separately. I was told by one mechanic to tap into the side of the injector pump where the fuel is coming from the fuel filter to the pump? It sounded right becuase I want to be able to read fuel pressure and know when it drops that it's time to change the fuel filter and know if my lift pump is getting weak or not? Any suggestions would be appreciated, jsut want to make sure I do it right, thanks.

AH64ID

Get a tapped Banjo bolt and put it in the CP3.

A snubber shouldn't be needed for an electronic sender.

http://www.glacierdieselpower.com/pr...x?pf_id=3418TB

kkime

What is the CP3 and when I ordered the gauge they told me I needed the snubber?

AH64ID

The CP3 is the injection pump. Its mounted on the engine.

What gauge do you have?

Look at this link. The same banjo would work in the bottom of the fuel filter or the CP3, and will give the same reading.

http://www.dieselmanor.com/diy/CMS3-...ugeinstall.htm

kkime

I have a blue led fuel pressure gauge ordered on glowshift.com it supposed to read from 0-145 psi and comes with a sender unit and wiring harness, if I install it on the cp3, do I connect it to the line coming from the fuel filter? and what is normal pressure on a 06 5.9l and what is unsafe ?

AH64ID

Stock pressure will be 8-10 at idle. And will probably drop to about 5 at WOT. As long as your above 2psi your fine. (Bosch specs are -5 to +15, but most gagues dont measure vacuum and aren't as accurate near 0, hence 2psi is what I look for on the bottom end).

NickBeek

I agree.

The snubber can't hurt and many of the gauge manufacturers are denying warranties of you don't have one there.

I have the banjo bolt at the cp-3 and then a couple foot section of flexible hose with the sending unit on the end of that. It's raining pretty hard right now or I'd go get you a pic.

no_6_oh_no

That is an isolator not a snubber.

Yes, an isolator is needed to make sure the engine vibe does not damage it. An 18" grease gun hose works great and allows mounting the sending unit out of the way.

043500QC

You don`t need an isolator with an electronic gauge. Alot of ppl use the hose instead of the snubber.

no_6_oh_no

You do need an isolator even with an electronic sender becuase the engne vibes will mess them up. Just about all the vendors recommend isolating their units from the engine.

Your mixing terminology here, a snubber is a needle valve or adjustable orfice that dampens the pulse from a reciprocating piston pump so the needle does not bounce. An isolator is just a flexible connection that dampens any vibrations.

A snubber is not needed with a constant pressure delivery vane like these trucks have.

Yes, any rubber hose will do but a grease gun hose is 1/8 " NPT on each end and is easy and strong enough to use. Tapped banjo bolt on the CP-3 and female connector for the other end and its done.

043500QC

Ok, my EV2 FP gauge ( which is an electronic gauge ) doesn`t use an isolator, it uses a snubber/restrictor made by Autometer. All the electronic gauges I`ve installed all used this piece ....

http://www.jegs.com/i/Auto%20Meter/1...0002/-1?CT=999

I have never had any of my vendors ever recommend an isolator for an electronic gauge install.

no_6_oh_no

The electronic senders are all ready restricted to the correct size, why use another one? It doesn't really hurt anything other than slow down the change in readings but it is extraneous.

Even the EV's with no stepper motor you could hook directly to the CP-3 connection and not have issues with needle bounce. Only the piston pumps really need a snubber.

If you have a sending unit go bad you may have warranty problems. If the vendor chooses to warranty thats a different story but a lot of the manufacturers won't warranty unless it is isolated from vibration. May be the vendor just has not gotten that info or is choosing to ignore it because it is not an issue yet.

Take a look and the discrepency in the OEM sensor readings and the manual or stepper motor gauges. The higher the readings the more difference there is between them. There is a LOT of interpolation and smoothing in the OEM's for a couple reasons. One of them is the variations.

Just something to think about when mounting the senders.

AH64ID

It kills me that an isolator is need to keep the senders alive, the there are multiple OE senders that don't seem to fail at the rate the aftermarket ones do.

I currently have a 18" isolator on my oil psi line, and its slow to read in the winter. I think I am going to remove it (or really shorten it) and see how long it lasts.

no_6_oh_no

Suppose it has something to do with cold oil in the line that doesn't warm very fast?

I think your right, 18" may be excessive for oil. Fuel and air generally don't have issues cold so more works for them.

OE sensors have never lasted as long as they could or worked as well as a manual gauage on these trucks from the begining. Have replaced more than a few trying to solve low\no readings. Gave up and added isolated senders. Works better for me.

kkime

Well I havnt got my gauge in the mail yet prob tomorrow and not sure what all comes with it, I know for sure a sender unit and wiring harness, they told me the part number I had to have which was the snubber and I got that already and It's looks like a threaded elbow valve to me nothing else, I dont think mine comes with an isolator do I need one?