6.0 Hard start hot NOT HPOP
 

Ok Boys….here it goes. I bought my first diesel Ford truck after many gas ones and it’s been all downhill. I got a 2006 F350, 6.0, crew cab long bed, 4wd with 200K miles, but it recently had a new crate Ford long block installed in it just before I got it. They also upgraded to ARP studs. I have the paperwork to prove the work was done. Seems the EGR or oil cooler failed and things went south. Since I got it I have installed 8 new Ford injectors with new hold downs due to potential bolt stretch if you reuse the old ones. I did this due to stiction(hard cold starts) and 3 injectors failed a cylinder contribution test at the dealer. Did the STC upgrade on the HPOP, upgraded stand pipes with Teflon washers, rebuilt the HPOP oil rails, new Ford oil cooler( Doorman crap one installed had deteriorated gasket), EGR delete (it already had this when engine was installed), blue fuel pressure regulator spring, alternator and 2 batteries, IPR, Fuel pump and water separator, SCT Livewire, and upgraded turbo oil supply line and drain. I also flushed the daylights out of it and put in a new radiator and heater core and Ford gold coolant. I only run Motorcraft oil and filters. I have done my homework. Thing runs great….when it starts. Here’s the problem. About 3 out of ten times she won’t start hot. Especially if it’s shut off just for a few minutes. I know what you’re thinking but the HPOP is great! The IPR screen is clean and the HPOP pressure is way above 500 psi when it cranks hot!! I have to either crank the heck out of it like 3 or 4 times for 20 seconds or let it sit for awhile and cool down. The compression in all 8 cylinders is 390-400 psi and it passes leak down tests with flying colors so it’s healthy internally. Also air tested through the ICP and no leaks as indicated by good HPOP pressure. FICM voltage is good, grounds and battery connections are good as well. It cranks nice and fast too. Fuel pressure tests fine. IT NEVER THROWS CODES EITHER. I’m stumped. I even threw an OEM cam sensor at it. I went out and bought a Scan Gauge II as my SCT didn’t have a prompt to monitor cam/crank sensor sync. When it’s cranking it never shows sync until it starts….is this normal with a Scan Gauge? Even when the engine fires right up in the morning or the 7 out of 10 times she starts just fine hot, the sync doesn’t change from 0 to 1 until she fires. When it’s acting up, it never shows sync until it finally starts. I’m a really good shade tree mechanic but I’m ready to drive it in a lake!! I’ve dumped a ton of money into the thing to make it dependable and I really could use any and all help. THANKS and sorry so long, but figured you guys needed good background data!!

Welcome to FTE.:)

I've moved your thread to the 6.0L Powerstroke Diesel forum for better response.

Cam sync should be "1" while cranking

Wow...that's what I was afraid of, should show 1 while cranking even if it doesn't start. Since I already replaced the cam sensor, maybe it's a crank sensor that acts up when hot. It seems to happen the most when engine heat sinks after being shut off for 5 or so minutes. To me if it was wiring, it would throw codes of act up going down the road as the wiring is moving around.......hmmmmmm

And BTW, thanks for moving post!!! I'm new to this!!

It's a long shot to get a code for crank and cam sensor failures. I've had quite a few. What's the fpw while cranking. Need to watch that.

So it starts 100% of the time cold and runs good? It only fails to start hot?
It sure sound like a ICP leak, double check ICP/HPOP data.

I know...it sure does sound like hpop....but on my sct and scan gauge both show good readings. I've done the air test twice with air fitting in valve cover where the ICP goes. I even leak down tested the HPOP system while commanding the IPR closed with +12volts. I can see instant good HPOP build with the IPR duty cycle not even close to being maxed out. That's what's got me so stumped.

Your going to have to take your readings Exact SO Make sure

set the SGII update rate to FAST

The SGII MUST update During the Crank to get Good DATA maybe you did IDK But one misread and folks end up throwing parts

SO you probably have Sync Unless its a Short Circuit that's Random Fail


You need to Post the Following sensors @ Crank Idle 2500rpm Truck Hot EOT @ 185 A/C Off

and during crank only when it don't run

Volts
RPM
ICP
ICPV
IPR%
FICM MP
V-REF

Ok...I will make sure scangauge is set to fast update and also post the requested data. Thanks BLADE35!!

Pardon my ignorance, but whats FPW??

Fuel pulse with = the time the injector is open

I have been chasing down the exact same issue on my 06. All of the numbers are good on my sct and I cant duplicate it. Mine has always started as well just occasionally wants to act up. A few weeks ago I took and cleaned battery cable ends, all ground points on the frame and motor and all positive connections i could get to. and that seemed to help. Especially with all the work you have had done check those ground cables take them off clean them and reattach. The driver side ground on the frame was loose, the starter positive was loose too. Also load test your batteries. You can have a bad cell and it will still crank fine. With all the computers and gizmos on them they can act weird without good grounds and batteries. I also unplugged and reconnected every wire and harness I could get too. Cleaned them with electrical contact cleaner... Mine has worked great since I did this but I am still watching it.

Good luck

Daniel

Have RPM signal when it wont start. ICP shoots up to 750psi with only like 24% Duty cycle. FICM and other voltages look great. No fuel pulse width or sync. while cranking when it won't start. Installed new cam sensor already and just threw a OEM crank sensor in as well...What a PITA job that is as it's under the AC compressor. Tried wiggle tests and everything else I can think of....Scangauge is set to fast update...My understanding is it won't raise IPR% without Crank signal....which it does go up to around 24% and quickly rises to well over 500 PSI. Also, it's my understanding that RPM is derived from both crank and cam sensors so I guess they are working. Still no sync.....I am about to give up....

What is the FICM logic power when it wont start? Do you know anyone with a 6.0 that you could try doing some parts swapping with, like the FICM or the PCM? Also when it wont start do you hear the fuel pump running? It should run for approximately 20 seconds after the key is turned to the run position. Have you looked the harness over really good for chafing? Here is a link to the wire chafe PDF from the tech folder that shows some common chafe points, https://www.ford-trucks.com/ford-man...re_chafing.pdf , one spot I found chafing on mine is where the main harness goes under the air filter.