QUICK HELP!! Fuel Pump Replacement

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Jan 7, 2006 | 11:36 AM

#16

Fat Diesel

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Joined: Aug 2005

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From: Morgan Hill, CA

Roger that.

Jan 7, 2006 | 05:02 PM

#17

blown99

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I wouldn't worry about hurting the injector o-rings. One side of the fuel oring can see 4000psi with the high pressure oil system under load. The plastic fuel housing could be an issue though but would take more than 70 psi to break/crack it.

Jan 7, 2006 | 05:47 PM

#18

jtharvey

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Joined: Oct 2004

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From: Columbia, MO

Where did those specs from teh o-rings come from that they can see 4000psi? Just curious.

Jan 7, 2006 | 10:15 PM

#19

blown99

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A navistar high pressure oil pump system can put out 4000psi under full load. If you look at an injector you've got the top set of orings which seal the high pressure oil from leaking into the valve cover area, the famous pink o-ring that seperates the high pressure oil and fuel and then the lower oring which seals the fuel from leaking past the injector into the cup and then into the cylinder. So even if at idle you made 465psi on the high pressure oil side, you are still way higher than the 70 psi on the fuel rail. The 4000 psi spec came from 10 years of data logging and performance troubleshooting DT 466E, 530E and T444E, all which use the same injector body, sleeves and o-rings. Different horsepower and torque ratings have different ICP pressures. A lot of low power complaints are due to a hpop not putting out the rated pressure.