MadFrog

I have had performance issues with the truck for a while, and i am pretty sure it is due to a failing pressure relief valve. I will confirm that this weekend.

Anyway, my only relevant mod is a quad race box, which isn't supposed to raise the pressure too far.

the question I have is: do I want to replace the pressure relief valve with another stock one, or wait for a modified one to be release to the after market, or just cap the rail and fuggetaboutit?

the obvious concerns are:
- stock will possibly fail again, at $350+ a pop, I don't want to keep replacing
- aftermarket isn't out yet from what I can tell, and they might still fail but will be rebuildable
- rail cap is a concern because I would be losing the fail safe and putting even more stress on the injectors.

so, what would YOU do?

thanks in advance for any information and/or opinions you may throw my way.

CD in NM

Hey MadFrog.

You are thinking/sinking in the same boat as the rest of us, welcome to the club. The first code my new truck threw was about rail pressure, too low. I took it into the dealer, they did some kind of a flash, turned me out - kind of NO known problem just a computer screw up, fixed the computer so it would not give me the code again? What about the pressure, am I OK? It all left me with an uneasy feeling, certainly not warm and fuzzy!

I picked up a rail pressure cap kit just in case the valve did fail, stuck wide open, and I might be somewhere out in the middle of nowhere and leave me with NO rail pressure. It's in my toolbox ready just in case. I've had much worse roadside repairs than putting in a rail cap. I like you, could forsee that this would put all the strain on the injectors, maybe not a good idea.

I am hoping that the aftermarket will be out soon, then I will make the exchange and see where it takes me regarding rail pressure. I have a rail pressure gauge on it's way, should be here in a day or so, and I plan to monitor the rail pressure before making any firm decision regarding what to do next. It may be that I just end up putting on the kit, or I may go in the direction of changing out the valve with an aftermarket.

One thing that I have noticed in reading all the threads about injectors, relief valves, etc - is that those who have upgraded their injectors to a +50hp injector and also capped the rail, they seem to/or are not having fuel pressure problems and injector problems anymore. I could have missed any new complaints about this stuff after their mods, but it seems as though the combination remedied their problems.

Maybe this comment will bring up some info regarding the status of those who went to the next size up injector and plugged off the valve?

CD

MadFrog

yeah, I have a gaggle of gauges that I need to install:
- lift pump fuel pressure
- oil pressure
- rail pressure (waiting on the gauge to come in)
- oil temp

I am probably going to temporarily hook up the rail gauge and monitor it, both in current state, and then with just a solid 14mm bolt in the relief valve to see what difference it makes. From there, it's either a cap or a new/aftermarket relief valve, depending on how often the rail pressure sensor gets maxed out.

wap

Where do you get rail caps. I have been contemplating some of these same issues and would cap mine in a second if I wasnt so paranoid about my injectors. But havin a cap in the tool box is a good idea.

bob4x4

I have seen over 29kpsi on freeze frame data from a quad box....and yes the valve popped...........

Bob

Timinva

I run a Floor It Cap and just moniter rail press. I try to keep the press below 25k except in competition. I keep my relief valve wrapped and in my tool box, just to keep wear and tear off it during everyday driving. With Floor it's cap you can not tell it is capped. The cap looks exactly like your relief valve only there is no hole through the center. Everything hooks to it like stock. I dont think these are readily available yet but will be soon. Tim

Luken

Floor It's caps are nice. I'll be running one when I put his pump on.

Sloverado

I will be too.

cquestad

I think I am ready for one...time to call John.

XLR8R

Has anyone thought of drilling a smaller than stock orifice in a rail cap to raise the valve's opening point?

PourinDiesel

I just got rid of the fuel line and blocked the rail off with washers.