fuel PSI

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ramhunter9

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Well after the turbo swap I noticed a drop in PSI at WOT ..

Idle is 20psi
cruising 17-18psi

Now WOT 9-10 .. WTF ?
 
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ramhunter9

ramhunter9

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From my readings .. and someone clarify .. There is a screen on the raptor inlet that could be causing the drop at WOT .

But if its clogged why wouldn't it drop PIS on idle ?
 

badfish888

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dave, on our detroits at work they do the same WOT is 2050. the way it was explained to me a school was at WOT the injectors open an additional passage way with bigger holes, causing a more dense fuel mist but dropping pressure from the added passage ways.........if that makes sense, not sayn at all thats wat u got cause i have no clue bout ur injectors, but i have seen it before on other diesels....................my $.02
 

Mopar1973Man

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Best why to explain...

As your demand volume of the VP44 increase above the supply volume the pressure will decrease. So now that you capable of turning up the Quadzilla and produce more power it takes more fuel to make said power so there is a pressure loss.

But now looking deep I would double check the pump for that screen I've heard some say the new ones don't have it but the older ones did have a screen in the suction port.

Also with the cooler weather the fuel will thicken more so like me on a cold day I can pull deeper into the pressure loss till the fuel in the fuel tank warms up once it does the pressure loss is reduced again like summer time.

So do a little checking and report back what you find...

EDIT:

Also do you have a snubber/needle valve on your gauge or is it just plumbed into the fuel system?
 
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ramhunter9

ramhunter9

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No snuber , line from tank to raptor .. ya so Guess I can pinch it off
I will be checking the screen after work today .

I also should note MoparMan is correct this was ran on #10 . Ran on 6-7 PSI at WOT 14-15
So its the higher I go in programing the less PSI at WOT

I hope that screen is dirty
 

Mopar1973Man

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Another good question do you have the stock line between the stock fuel filter to the VP44? If so there is you restriction...

sfcuf4.jpg

Compared to 1/2" Big Line fitting...
2zsmw5l.jpg

Or side by side...
fuel-line-difference.jpg


But still even my AirDog 150 doesn't drop that much... You've got a Raptor 150 which is the exact same pump just less the filters.
 
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ramhunter9

ramhunter9

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Mike , I have the OEM line from the VP44 to the OEM filter .. And I cracked the raptor open and the screen was spotless . Ran the truck on #2 setting and same thing .
I did notice that at idle it bounces from 21-16 and crusing is 16-17 but at WOT still drops to 9-10 ?

If the fix is the new fitting ... link me to a place to get it .

On a side note ... changed my T-stat and that fixed the putting it into drive and killing it thing at first start up . My gauge now reads 190 with hi idle within min 's
 

Mopar1973Man

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ramhunter9

ramhunter9

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Big line kit ordered .... Thanks Michael
 
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ramhunter9

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Big line kit is on ... now 1/2 inch lines are all complete .

WOT drops 1-2psi , not the 5-6
and I installed a needle valve off the VP to the PSI sensor on my display so it does not hammer .

And the turbo is finally getting its new color ..LOL

592606c9.jpg

12552bef.jpg

Also replaced all 6 of my injector tubes with new O-rings
 
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ramhunter9

ramhunter9

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Oh and Mike ....

No more hard start ! New tubes fixed that ..lol
 
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ramhunter9

ramhunter9

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Nope all me .. and the first time I also did the swap . He was just there to coach as it was my first time .

Now I do injectors for fun ..LOL

Easy job
 
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ramhunter9

ramhunter9

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And I didnt take the rails off Mike , just loosened the nuts and slid them out of the way .
Also

Since the bad o-rings were leaking internally causing the hard start issue , I smelt fuel in the oil so decided to change the oil now that the leak is fixed ....

Well bought the 11 quarts and filter and went to work .. drained the old (it was real thin with fuel ) all said in done I had a extra gallon of old oil in her from the leak .

Glad this is over .
 
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ramhunter9

ramhunter9

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Next video will be on the dyno :********:
 
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