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Discussion Starter · #1 ·
So, I went to Relentless Diesel today and had the rail capped with a cap from FTE Diesel. Chris at Relentless said the rail was only leaking slightly. Once I started it (and cleared the CEL:lol4:) I immediately noticed a difference in how the truck ran, EGTs were lower, much lower, even at idle. I thought my pyro was off because i could barely get it above 200F on high idle. I also noticed the truck is much less sluggish - maybe my torque converter is less mushy than I thought.:headbang::party018::party018:
 

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Discussion Starter · #2 ·
I also wanted to give FTE a big thanks for great customer service.:yourock:
 

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Your truck has a problem if you can only get 200* EGT on high idle.

Or, on edit, maybe my truck has a problem! I'd be much closer to 350* on high idle.
 

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Discussion Starter · #4 ·
I was running SW #1 on the smarty so maybe thats why. I will do some more driving later, its rainy out, so I cant push it right now, but I will report back later.
 

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Discussion Starter · #5 ·
Your truck has a problem if you can only get 200* EGT on high idle.

Or, on edit, maybe my truck has a problem! I'd be much closer to 350* on high idle.
I don't know what was going on but I think 350 sounds about right. I will try it again, probably tomorrow.
 

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Rail cap? What and where and how and why?
 

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Discussion Starter · #7 ·
Rail cap? What and where and how and why?
What - replaces the fuel rail pressure relief valve.

Where- on the fuel rail

how - it is basically a solid bolt that fits the threads of the relief valve

why - if you have a pressure box, there is a good chance you are leaking pressure/fuel
 

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Does running with the rail capped have the potential to cause injector damage?
 

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Does running with the rail capped have the potential to cause injector damage?
Yes, thats why you want to run a rail pressure gauge.
 

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Discussion Starter · #10 ·
Yea, I have a pressure gauge on the MPD monitor that came with the MP-8.
 

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Diesel Junkie
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What pressure does the valve bypass at? I run the X2 stacked with the Smarty and my RP gets up to 29k on a hard run.....just wondering when the valve is opening.
 

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Discussion Starter · #12 ·
I think it opens somewhere around 26,000 psi. Since I have had my rail pressure gauge I have not seen anything over 22K. I have not been able to try for 26K since it is still raining heavily here.
 

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where does this install. i seem to have some fuel leaking by my power steering pump some wheres
 

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ILLINOIS NORTHERN VP
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Correct me if im wrong but i never got the "good" of this.
Wouldnt you want the rail cap to pop rather than hurting your injectors?
Nick
 

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Yes that's why you have to have a guage and watch it

The good, I guess, would be that your relief valve would not leak, cause you don't have one.
 

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By the way, what check engine light did you have to clear? Does replacing the valve throw a code?
 

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Correct me if im wrong but i never got the "good" of this.
Wouldnt you want the rail cap to pop rather than hurting your injectors?
Nick

I know people who have done this because their pressure relief valve popped and they're having trouble holding RP.

Capping it is much cheaper than replacing it, and they're obviously running high enough RP that the new one would eventually pop as well.
 

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so when the pop they will leak? and where abouts is it cause i do got some fuel leaking up by the powersteering pump?
 

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ILLINOIS NORTHERN VP
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I know people who have done this because their pressure relief valve popped and they're having trouble holding RP.

Capping it is much cheaper than replacing it, and they're obviously running high enough RP that the new one would eventually pop as well.
But it is also cheaper to replace the cap instead of the injectors. :lol4: idk maybe im just not getting the point.
srry guys
Nick
 

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Discussion Starter · #20 ·
But it is also cheaper to replace the cap instead of the injectors. :lol4: idk maybe im just not getting the point.
srry guys
Nick
I have a rail pressure gauge. There is no point in replacing the relief valve because it will just start leaking again. They are not high quality. I was driving around with my truck leaking fuel, so the benefit of the cap is that I'm not paying for fuel that is just being leaked out of the fuel system. Stock injectors are capable of handling 26k psi, the problems occur when you don't have proper filtration. I have a 3 micron fuel filter and air seperator (FASS). I have the necessary filtration. I watch my rail pressure as I drive and make sure it is acceptable. If you like to pay $2/gallon just to let it leak out all over the place, be my guest, but I like to burn my fuel.
 
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