My Fuel rail preasure sencer went out today again this one only lasted 4 months or so. Not very happy. I thing the quadzilla gauge is taking it out but not to sure. Is there a better gauge than this one??

 

Well I have had my DiPricol since they first came out, at least two years now and it has worked fine. No rail pressure sensor issues for me so far.

 

Dump the MP8 and the quad and put a TST on there with the R49 option....

 

When mine went out my dealers diesel tech back in Alaska also said it was the Commander's fault. He said because it's tapped into the RP sensors harness, it's messing with the voltage for the sensor. At the time, I thought BS, but to be on the safe side, I never hooked the RP wire tap back up and haven't lost a RP sensor since. Coincidence? Maybe....

 

There is more to this than a rail pressure gauge "taking a sensor out".

First look at the rail pressure gauge like a volt meter. We simply take a reading off of it. We do not lower or alter anything on the line. We simply make a connector with a "T" into it and read the voltage.

We do not use power from the sensor (that is supplied via 12v at the fuse box), we do not use ground from the sensor (that is supplied by the battery or other ground on the ring terminal).

Same exact thing can be said for the Commander. We simply tie into the wire and watch it. Exactly the same as if you stuck the wire with a voltmeter. Do you guys really think you could kill a sensor by sticking it with a voltmeter?


Now, I think there is more to it. I have not fully researched this so there is more info needed.

First, why do we think the rail pressure sensor is bad? Is it simply because it set a code? If you clear this code does it continually come back? If you unhook electronics from the RP sensor will the code clear?

One of the common things I tend to see with failed sensors are CP3 mods, or aftermarket pumps. Is it possible that more pressure on a regular basis is harmful to the sensor?

Is it possible that some of these trucks are 4 or 5 years old and eventually these "pressure" type sensors are prone to fail on the cummins?

I think there is more to the story. I want to know what happens when they are ruined or what makes you think they are ruined. If its a code, then it is probably fine and there is some other issue.

 

Quad- My truck was 3 years old and the sensor went bad 2 or 3 days after I tapped the wire. The mechanic at the dealer had a theory that the tap had cut too many strands of copper and was restricting electricity. I talked to your folks back when it happened, and basically was told the same thing you have said. BUT, when I need my truck to not be in limp mode so I can get to work every day, RP becomes unimportant (P0192 that would trip every time I started after clearing the code until I unhooked the RP wire tap). Once I unhooked the tap, the tech at the dealer was cool enough to swap out my sensor under warantee "just in case". I'm not willing to tap that wire again, coincidence or not. What I REALLY need to be able to monitor is FP, but I'm still waiting for your sending unit fix...

 

That means it did not "take out" the rail pressure sensor. Could there have been some sort of issue or malfunction, yes. Did it "take out" the sensor, No.

That is what I am getting at, not just in your case but, in all cases. Many times people have several things plugged in or modified that could be a culprit or part of the problem. While there can be problems I do not subscribe to the theory that any of these things are "taking out" sensors. Not just my products either.

Now, back to your truck. If you tapped the rail correctly and had our module on there like in your signature then the wire that was "restricting electricity" is still cut and still does not have enough strands of copper. I don't buy that. You can run the same amount of voltage across 1 strand of wire as you can 50. You cannot run the same amount of current though.

So, here is my theory, if you had it tapped on the input side, that should not affect anything. If you have it on our output side (the wrong side) it could have limit our ability to drive the signal back to the ECM, causing a CEL.

On paper that works like a charm. What does not work is he replaced a sensor whether he needed to or not but, it sounds like the wire is the problem according to that tech, yet there is no mentioning of fixing that problem?

My personal guess is there is something not quite right on the Commander, it caused the CEL. If you leave it hooked up and clear the code it comes right back because there is indeed an issue. More than likely if you want to use the Rail pressure function the gauge should come to us to make sure something in either the wire or the board is not placed well or shorted. If you don't care to use it again, leave it alone but, stuff like that can be fixed and tested if you want it to be.


The fuel pressure sending unit is being tested. So far so good, as I have updates I will keep everyone informed.

 

I had issues with the quad gauge also and recently had the same issues the sensor was junk. I removed the quad gauge right after I was getting voltage codes and no more problems since then. I would take it off your truck

 

I've had the quad guage on mine for 30k miles, no issues on the rail pressure side, the fuel pressure sensor is worthless. It worked for about an hour.

 

I have had an mp8 for 3 years, and no sencer problems. This year I added the quad gauge and so far I am on my 3rd fuel preasure sencer I think it may be clear to what is the problem I am not going to hook this quad gauge up again it is coming out of the truck..

 

Dose this read rail preasure??

 

YES IT DOES!!!! And I have to say the modular usage of this unit is awesome. You can view BOOST, EGT, RP. You can modify TIMING, RP, HP, TQ. There is HI BOOST and EGT limit defueling, as well as cool down timer and EGT timer.

You can pick them up on here for 450-600 in the classifieds. Make sure it is the R49 modl though.

 

Are you guys using dielectric grease on all the connections when installing the RP gauge?

 

For those that don't know...

 

Another example of DID NOT "take out" RP sensor.

You know my first post is pretty informative and asks a few questions to try and help. Is there a reason you felt like repeating yourself without any further explanation?

Lets see you have an MP8 which breaks the signal to the Rail Pressure gauge and it uses the 5v power and ground from the sensor to power the module.

Then you have a modified CP3 which makes more pressure than stock.

And you have a RP gauge that simply T's into the line like a voltmeter yet the RP gauge is 100% at fault?????

You still have not given an explanation as to why the sensor it bad. Several other people on here said it "took out" their sensor but, push come to shove, the set a code, unplugged some stuff and the senor was fine.

So, give me a little feedback and lets figure out what the deal is.