OK so my 08 f450 finely died and will not start... Still NO Codes. I have 4700# fuel pressure trying to start I am using auto ingenuity software. I cant get a crank sensor reading and i dont see it on the list to monitor. So what is wrong with it?? It is DPF and EGR Deleted running a Mini Maxx. I put it back to stock and got all EGR and DPF codes nothing else. So where should I be looking... Crank Sensor?

 

does the truck crank over? does the aftermarket fuel pump use the original sending unit in the tank? possibly getting air in the fuel system, maybe try bleeding it.

 

Turns over, wont start. No air in the fuel i have pressure just not firing. Ran perfect the day before and went out to start it the next morning and been dead since. It would randomly cut out before this.. thats why I was thinking Crank Sensor but no codes

 

You reprogrammed the pcm to stock as well?

 

Yes my thinking was maybe it would show codes..and it did only the egr and dpf codes so retuned it still no start

 

As far as I can recall...a 6.4 requires 5000 psi to start. Not sure if that 300 psi difference will matter or not... Your software should have a CKP sensor PID...if nothing else, your MiniMaxx will.

 

normal idle psi is sometimes 4.9, but usually 5 to 5.1 psi (X1000).

 

OK so ......... I put the truck on the batt charger and let it charge cranking rpm went up it was 145 and in the red got it up in the green retuned it and fired right up... it has 5100# fuel pressure at idle so good to go there ... funny thing it just doesn't seem like the batts are that low. So what is the voltage needed for the computer and if it gets low will the computer shut it self off
Also the cam and crank sensor sync goes to red off and on from 0 to 1 is this telling me that one of them is bad?

 

could just be bad battery. the electronics on newer vehicles are very picky. id have each battery checked individually you may have one bad and would need replacing in pairs, are they original?

 

They are optima yellow tops but they are probably 3 years old. Trying to go tomorrow and pick up a new pair.

 

Could be wrong but last I heard yellow tops aren't really meant for high current draw applications, like starting diesels or running winches. Deep draw yes, high current draw no. Maybe better off with Red Tops?

 

Rpl the batteries and start over with your trouble shooting. Don't replace anything else.

 

I read a bunch of posts that suggested yellow tops for our trucks AND I just installed two. I'll be sure to report back in the future if there are any issues. I have a winch on a cradle for the truck and one in the trailer but they are on a solenoid that only gets power when the truck is running.

Maybe, we should use yellow top and one red top?

 

OK so I put 2 in new battery's and the truck wouldn't start .. retuned it and it fired right up and ran great. came out in the AM started right up ran great to work, so we will see. the Cam and crank sync is still showing 0 then 1 and green to red back and forth. is this a bad crank sensor? I know the cam sensor is good I replaced it like 2 month ago.

 

I wouldn't go back to a red top ever again myself. They are pure starting batts and their warranty is void if they can determine you've been winching (deep discharging) -- had one on my Jeep for all of 2 years and it started crapping out. I don't know why folks aren't recommending the blue tops? They are meant to both start and deep cycle (marine batt)...