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6.4 runs rough, losses rail pressure fast

6K views 15 replies 5 participants last post by  stroked99_1/2 
#1 ·
Hey guys I just bought an 08 job 2 6.4 I am workin on it right now and it takes ALOT of cranking to get it to start again, it does not have any injector codes but it has these


Cylinder 2-8 GP circuit open (But the GPs are unplugged and VC is off so I can see in there)
MAP - exhaust Pressure Correlation
Diesel Particulate Filter Pressure Sensor "A" Circuit Range/Performance
OBD Systems Readiness Test Not Complete

Thats it for codes, But it took two batteries worth of cranking to get it to start this morning in the shop, and it ran extremly rough so I shut it down fast, then I tried starting again, and it took a lot of cranking to start again. This was only 30 sec after it had been shut down. I am thinking that it has some burned up nozzles or a bad pump, anyone have any ideas on this as to what it would be?? Do the injectors or pump throw a code when they are bad? I am still new to the 6.4 myself so any help is appreciated.
I would run a test on rail pressure but I am scared to keep it running for fear of doing more damage to the internals incase its an injector sticking open.
Oh, the wrench light is on the dash, as well as oil, whatever those mean.

The Warranty is up so thats not an option.
 
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#2 ·
Pull the top fuel filter inspect for metal shavings first thing. If there is metal shavings your pump is done and probibly a few injectors due to eatting the metal.
 
#4 ·
Ok, I will do that. It was put on a ford IDS, and then a power balance was run, and it showed a few dead cylinders when a load was applied I am told.

I have a Matco Determinator scanner, but I do not know if it is possible to run a "buzz" test on injectors like I can on a 7.3?
 
#5 ·
Sounds like you got a couple injectors hung open then and the HP pump cant keep up is my guess.
 
#6 ·
That is what I am thinking, If they hang open will that burn up the nozzles and also crack pistons? I'm really hoping I don't have to do any bottom end work.

I pulled the filter and there were no shavings in the filter, there were a few shiny, tiny spots on the bottom of the filter housing but only two or three and they didn't seem like shavings out of a pump.
 
#7 ·
Im doing hg's on mine right now and just pulled my fuel filter and got a few little spots to so it shouldnt kill yours. If ran long enough it will crack a pistion if caught in time you can just stick new sticks in and go. You would know if you cracked a pistion you would have a ton of blow by.
 
#8 ·
Yeah thats what I figured, but its not even drivable, I start it (after a few minutes of on and off cranking) and then it runs and the idles like #### and down to 500~ rpms, can accelerate or anything.. we will see I guess. I am going to buy some new sticks and try that I guess.
 
#9 ·
you know that sounds to me like you have a gasket messed up on a injector and its pushing combustion gas into the fuel system. But its that or a stuck open injector. Even if its the gasket on the injector you need to replace it.
 
#11 ·
yup thats what i mean
 
#15 ·
first off make sure you dont have excessive back pressure from the dpf it should set a p2463 and p246c should be no more than .5 psi at idle, then check for metal from the hpp again but this time take the #1/2 injector line off which ever side you have off and crank fuel into a container and check for metal it will be very small so pour it into something you can look into easily if you find some replace the hpp, all injectors, fuel cooler, both rails, the 3 flex lines, both filters and flush both the lines from the tank and replace fuel filters. see it all the time at the shop i am in the middle of a hpp system right now also if the oil is over full check the cac for oil and do a compression test on 2 and 8 they will melt first if the crankcase is over full.
 
#16 ·
2 is low compression, So I ended up pulling the motor out. The turbo and ex pipes were Caked in oil and it all smelled like burnt oil so I am pulling that motor apart to see if it is rebuildable but I have another one I put in that truck so it will be alright. I hope, But I will keep you informed as to what I see. I think someone ran this thing even while the injectors were bad for quite a while.
 
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