Injector leak test

[Nhramember]

I still am getting code559 active then inactive. Did cutout test all passed. Do I have to buy the whole cap off kit or just 1 to test them individually ? The fuel pump is a lil bit over a year old new tappets. It’s got a new banjo bolt in the back of the head too.I’m gonna check pump too. Ideas anyone. Thanks

[Rawze]

will it pass a leak-down test?...
what is the leak rate in one minute?.
ref: http://rawze.com/forums/showthread.php?t...3#pid75483

[Nhramember]

Hey rawze I noticed the code just code came back on at the top of 12 th gear 1400 rpm. Never does it in the lower gears. I’m gonna run rail pressure test again .

[Nhramember]

(11-20-2023 )Nhramember Wrote:  Hey rawze I noticed the code just code came back on at the top of 12 th gear 1400 rpm. Never does it in the lower gears. I’m gonna run rail pressure test again .

Ok just did 2 fuel leakage test first was 28967 minus 23639 at end of first equals 5328. I ran a second test 28885-23650 equals 5205 in 1 min. There is a leak right ? Put new fuel pump and tappets in last year. Where do I go now to check for leak. Thanks Nate

[Rawze]

maybe this thread helps...
http://rawze.com/forums/showthread.php?t...9#pid78669

[Nhramember]

Gm everyone l replaced the number 6 injector and engine is holding pressure now only lost 250 psi within the 1 min leak down test. I am still getting 559 code active then goes inactive. Put new valve on the fuel rail. It’s still saying lower than expected fuel rail pressure. It does it on acceleration in 12th gear or 13th. I have a new high pressure fuel tappets etc. I been chasing the problem for a month now. Do you think the water separator or fuel lines maybe the culprit. I lose boost when the check engine and wrench come. I am trying to figure what to change next. I’m trying not thru parts lol. Thanks for all the help.       

[Rawze]

In those photos there is about 900bar of difference between the commanded and measured fuel pressures. That is too much. It should only be about 350bar or so max.

Was that (measured pressure) the highest it would build up to during the fuel pressure leak test?.

FYI: during the fuel pressure leak test, it should be getting up to 29,000 psi (measured) .. and then still be above 25,000 psi after one minute with engine shut off, just like the video referenced above shows. If it cannot get to 29,000 psi then you still have an internal leak somewhere.. That or something is wrong with the fuel pump, or its regulator at the back of it itself.

If it is passing leak down tests at full pressure (29,000 psi) then ...



maybe an inlet restriction (banjo fitting screen is clogged, restriction in the lines somewhere, etc.).

..

or the pump itself is not keeping up with demand.


========

Worse case scenario if you just cannot solve it ... make an appointment with Haggai Automotive down in griffin, GA (high falls road). - I bet they could figure it out pretty quick. They are really good at finding these types of fuel issues with the common rail engines. At some point ya just gotta bite the bullet and say enough revenue loss is enough and get some help/second set of eyes on it if you just cannot figure it out for yourself.

[Nhramember]

(12-06-2023 )Rawze Wrote:  In those photos there is about 900bar of difference between the commanded and measured fuel pressures. That is too much. It should only be about 350bar or so max.

Was that (measured pressure) the highest it would build up to during the fuel pressure leak test?.

FYI: during the fuel pressure leak test, it should be getting up to 29,000 psi (measured) .. and then still be above 25,000 psi after one minute with engine shut off, just like the video referenced above shows. If it cannot get to 29,000 psi then you still have an internal leak somewhere.. That or something is wrong with the fuel pump, or its regulator at the back of it itself.

If it is passing leak down tests at full pressure (29,000 psi) then ...



maybe an inlet restriction (banjo fitting screen is clogged, restriction in the lines somewhere, etc.).

..

or the pump itself is not keeping up with demand.


========

Worse case scenario if you just cannot solve it ... make an appointment with Haggai Automotive down in griffin, GA (high falls road). - I bet they could figure it out pretty quick. They are really good at finding these types of fuel issues with the common rail engines. At some point ya just gotta bite the bullet and say enough revenue loss is enough and get some help/second set of eyes on it if you just cannot figure it out for yourself.

It went to 29002 psi and it only dropped 250 psi in the 1min. It’s holding pressure. I blew air thru the tank suction line saw fuel waves in each tank. Can the hose be collapsing from the fuel water separator to the primer pump? How do you test the regulator?

[tree98]

Put a fuel pressure gauge on the compucheck fitting at the exit of the spin on fuel filter, monitor that as the actual pressure goes down from what's being commanded. That will tell you if you have enough pressure going into the high pressure pump.