6.0 cranks but will not start!!!
 

Hello every one I have a 6.0L with great batteries that will crank all day at 140-180 rpm and will not start. While cranking my Icp is around 900 psi, Ficm lug! Voltage is 46-48V Ipr Duty cycle maxed out at 85%. I have checked all my fuses under the dash and the hood the all seem ok, I have good oil and fuel etc.
When I pulled my top filter I had fuel, there I sucked it all out and let the pump fill it back up in about 5 seconds, I then unplugged the fuel pump to watch for combustion bubles to enter but there was none. I then watched the fuel level while cranking and the fuel didn't seem to leave the housing. So Iam not sure if I have a ficm wiring problem, PCM problem or what, but it seems like the injectors aren't geting fuel to them. When I buzz tested my injecors # 8 didn't buzz and I do I've a koeo code for that injector but that shouldn't cause a no start right?? Iam just right now stumped as to what the problem could be lol so any help at all is greatly appriceated .

O-rings on the high pressure rail.

You mean dummy plugs and stand pipes to the oil rail?

Dummy plugs bottom o-ring. I had the same problem with mine but when it was hot.

Give it a shot of either threw the filter minder (if stock intake) and see if it will crank on that.

Update: I pulled the valve cover to inspect #8 injector and replace dummy plug and stand pipe and I found the injector solenoid screw broke off gone and the injector in two pieces I got it out replaced it but it all back together and it's the same as before crank no start icp all good I might pull the other valve cover tommorow. Has any one else see an injector do this? Lol

And either doesn't do anything or help at all still cranks all day and sounds like it wants to start but just won't.

When you had your problem was your icp pressure good tho? Mine stays around 900 psi.

I tried a donor PCM but it made no difference

I would look into why the ipr is at 85%, what year is your truck?

Im no ford guru but the 06 6.0 outside my house had a bad fuel control unit fixed it and it fired right up.

Truck is a 05 and the Ficm tested good at 48V

My icp was good. Let me make a call and get some more on what else to check.

Ok thanks bud you can call me if you want 301-712-2565

Update: I tried a good Ficm but still the same and my fuel pressure is good at 48psi cranking, and I even blocked off the fprv just to make sure I wasn't returning my fuel to the tank. Iam really stumped lol

Did you ever pull the other valve cover to make sure there isn't a secondary problem? And I don't understand why it won't fire on either, it should at least start.

HPOP? i know in some cases they cause a no start symptom, icp sensor and ipr valve too, I'd replace them both, cause it sounds like you're into it now

It probably won't fire on ether because the glow plugs are still activating. :lolly:

I want to know why or where 900 psi while cranking comes from and/or how fast the engine is cranking to make this happen.

and a buddy of mine owns a shop and the 6.0's pretty much could keep him in business pretty easily, and a customer of his had this happen to him right after he installed an egr delete and the basics, IPR said it was functioning properly, still no start, then he kept trying it, and it would never go, so he just replaced the IPR and sure enough it fired right up, I'm not saying it's your problem, but he now replaces the IPR every time and EGR delete is performed

Not good, you need to disable your glow plugs and intake heater if you are going to use either. I am not sure if the 6.0's have a intake heater like the 7.3's. But I would check or just wait until your wait to start light goes out.

IPRs usually only fail because the HPOP is failing and throwing crap into the reg, same goes for the ICP sensor. HPOPs fail when the screen under the engine oil cooler fails, allowing dirt to enter the HPOP.
If a failure is detected as crap on the reg I always replace the HPOP, IPR, ICP and screen. Most times I also update the engine oil cooler while it's out. 90% of the time the injectors need replaced due to mileage or wear and the standpipes, rail plugs and FPR get updated. Engine oil always gets changed to 5W40 syn., Motorcraft filters installed & 2 bottles of Rev-X oil additive.
Change the oil filter every 5k miles and engine oil, fuel filters + 2 bottles of Rev-X every 10K miles.
If the root cause of failure is fixed every time they seem to stay together quite well.