Rail Pressure

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schroederMP

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Just got my gauges hooked up...

Fuel pressure stay at 17/18 while ideling and driving...and 14 at WOT.

Rail pressure...rough 7,000psi idle.

I have stock injectors.

At WOT my rail pressure will hit 26,000. Is it supposed to be that high? For stock injectors?
 

ladale21

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Bees I been
Just got my gauges hooked up...

Fuel pressure stay at 17/18 while ideling and driving...and 14 at WOT.

Rail pressure...rough 7,000psi idle.

I have stock injectors.

At WOT my rail pressure will hit 26,000. Is it supposed to be that high? For stock injectors?

Interesting numbers , I've been checking, your should be at 6-7 at idle, 4-5 at crank, that does seem a little high for wot but that is within spec of 27k but it itwill be putting a lot of stress in that relief valve
 
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schroederMP

schroederMP

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Thats for the reply man...

I did some research and apparently the Auto Meter gauges like to read high on the rail pressure...so I'm gonna hood a scanner up to my truck (brother is a mechanic) and see what the numbers are and compare
 

ramhunter9

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Auto meter does read high i have heard , Isspro does not , but they are expensive sets
 
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schroederMP

schroederMP

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Yea they are...plus I went with the factory match since they are right there with my factory gauge cluster. But...upon further researching...ISSPRO has there EV2's which are factory match. lol oh well
 

ladale21

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Yea they are...plus I went with the factory match since they are right there with my factory gauge cluster. But...upon further researching...ISSPRO has there EV2's which are factory match. lol oh well


lest us know cause those nubers put you close to the stock release presure think'
 
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schroederMP

schroederMP

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Yea I was thinking it was pretty close...haven't heard any rail pop or anything. As soon a I get it done I'll post up some numbers
 

infernoredram

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Now that I got the gauges, at WOT Im solid at around 21,*** PSI until I let off with my smarty at 100HP and quad at level 1
 

ladale21

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That intresting cause I thought 21k was low for WOT
 

Mopar1973Man

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So my 26,000 is way to high then?

Most likely... I'm not really savvy on CR engines but I pretty sure after 25K you taking a risk of cracking nozzles and bodies. Typically the results are rather damaging either with loose debris bouncing around in the cylinder or having uncontrolled fuel spraying in the cylinder.

Just think about the numbers your looking at 26,000 PSI! In a area no bigger than a postage stamp your placing 13 tons of outward force (pressure). Which happens to be 3 times more than your truck weighs!

Why not use a bigger injector instead of a programmer that is adding pressure why not add flow to the cylinder. Back in the early years (1989-1993 1st Gen) people use to turn up the fuel screw on the VE pump doing the same thing and use to rupture the injection lines getting carried away with stock injectors the cure was simple you can turn up the screw just use a bigger injector to ditch the pressure in a timely fashion.
 
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schroederMP

schroederMP

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Well what about aftermarket injectors? I've come to the conclusion that I have bigger injectors...so is that number still to high for them?

I really need to get a scanner hooked up to my truck to see if my gauge is off or not
 

ramhunter9

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Mike can back me on this one ..I once thought the previous owner had bigger sticks in my CTD .. not the case .. I swapped them out real quick .. ya gotta know the size of your sticks ... period
 
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schroederMP

schroederMP

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Thats the plan when I go bigger turbo...I'm gonna take these out and send them off to be tested. Make sure I know what size I have. If they are stock...well you'll be hearing from me again lol
 

infernoredram

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Correct me if I'm wrong, but doesn't it usually go air before fuel?

So would it be better to do a turbo before nozzles?
 
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schroederMP

schroederMP

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Yes...thats the best idea. I dunno if I have aftermarket nozzels or not. I'm thinking I so. I think the previous owner put them in. But I'm not 100%
 

Stangshcky12

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A larger nozzle should result in a lower rail pressure and lower temperatures actually
(kinetic energy blah blah blah)
Its not that he isnt getting enough air (well he might not be but its not really the problem here) so a turbo wouldnt really help to much
The truck seems to be putting more fuel into the rail then the nozzle can put out basically
 
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schroederMP

schroederMP

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Could it be a result of the lift pump pushing to much fuel?
 
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