fuel relief valve problems
 

Hi guys, Im having a problem with my 'new to me' 6.7 cummins. This is my first diesel but im learing fast!

The truck has straight pipe, smartyME, deletes.
The problem Im having is when I drive down the highway it throws code p000f, fuel valve opened. That is the ONLY code. When driving I can tell when it happens because the truck is down on power making almost no boost, BUT it does not 'fall on its face' like it should if its really blowing off 30k lbs of pressure!

The werid thing is its only going down the highway after about 30min. I can drive it wide open stop light to stop light and its fine!!

Any ideas? I dont think the valve is really open, mabey a bad sensor? something wrond with the cp3?
:argh:
(i have this post on other sites as well so if this is old to you then I appologize, thanks for the help)

have you ever shimmed the rail plug itself, and when it throws the code the ECM is gonna tell the truck to defuel so it will lower power levels. what do you have the Rail Pressure Revo set on for the Smarty

I have not shimmed the rail. But the truck is use so I'm not 100% sure wut the last owner did. The revo rail pressure is set to defualt. The code comes on even if I remove the smarty altogether.

you have either a bad rail plug or faulty sensor boss I can help ya by telling you how to shim it if your interested takes about a half hour and 3 little #4 flat washers

I read how to shim the rail, seemed pretty straight forward. I just didnt want to do it in fear of causing damage. Is there a way to check the sensor? or is the next step to shim the rail and go from there?

yeah shimming it is pretty easy just use padded jaws in your vise and be gentle with it. Honestly If I had to make a guess I would say the sensor is bad and not real way ot check it that I know of other than Chrysler Scan tool maybe. But pluggin or shimming the rail will let you know which one it is if you shim it and still get it money is on it being a bad sensor

Might be a bad sensor, or it may not be period. I'd have it looked at as mentioned above to be sure it's a sensor. $200 is a little much to spend on a new one, then find out it wasn't the problem.

one other thing I jsut thought of since you bought the truck set up the way it is there is a pssibility that they had put a industrial injection rail plug in it which we have found recently to have a pretty bad defect in them we believe. What the thoughts are is that the II rail plugs may not be machined at just the right angle which is allowing fuel to leak around the rail plug and return back to the fuel filter thus its leaking all the time (or most) whic will trip the FRP sensor and throw the code your getting becasue the truck thinks it has exceeded the pressure limits so this is a very good possibility to what is happening to you. Guys are switching back to the stock plug and have a world of difference in performance so not sure how you can tell if this is what is happening yet but ill check into it and if I find out more let ya know. Dont know what the rules are here about posting links to other sites so dont want to get in trouble but this is being discussed on the other site im on right this minute

That sounds like it could be my problem!!
that makes perfect sense. I know at one time it appears that this truck had a edge w/ att. stacked with the smarty.

if they were stacking the edge with the smarty 99% they plugged the rail and that is what is screwing you up the onlly way to tell is to try and find a stock rail plug in that case. PM coming bud

also do you have a Rail Pressure gauge this will tell us for sure if its bleeding or popping of or if its just a bad sensor. and if yor gonna run the smarty and do much more to the truck a Rail Pressure gauge is one your gonna NEED anyway. I like the Issopro EV2 just FWIW and get my stuff from James at rollinsmokediesel.com or Tony @ Mightydiesel.com both awesome guys to deal with tell them Buck sent ya. They are both vendors for my fab stuff!