2005 Excursion 6.0. Head studs; Sinister coolant filter (replaced Feb '20), Sinister regulated fuel return kit (Aeromotive regulator), Sinister Y-pipe, DC Power alternator; Banks high ram intake. Last changed fuel filters Feb '20 ~20K miles.

Hi, everyone. Thanks for reading. Problem started about two months ago. Truck was driving fine for past few years (occasional water in fuel draining - otherwise rock steady), then suddenly died at stop light (20 mins from work on way home). Noticed slowing crank for couple of preceding days. CTS Insight scanner showed 14.2+ volts while driving, so figured alternator is good. Found Motorcraft BXT65-850 batteries with dead cells after 15 months. Store replaced both under warranty (kudos to O'Reilly). Installed and all was good for three days.

Meanwhile, scanner showed a few glow plugs out (live in southeast Florida). Decided to fix. Replaced driver/passenger side plugs and harnesses. Scanned, still showed two out. Replaced glow plug module. Replaced air filter during this effort. All Motorcraft parts.

Driving home from work day 3, same stop light (which means truck was running for about the same amount of time), died while pulling up to light. No reading on tach. Tried restarting after 40 min cool down. No luck. Unplugged ICP and tried. No luck. Towed home.

Was ready for oil change, so completed that and filter. Next day (full cool down), very slow crank. Trickle charged batteries for a day each. Slow crank remained. Replaced starter with 6.4L unit (nice upgrade). Slow crank fixed. Assume old starter went while trying to restart when stranded. Truck still wouldn't start after new starter. Found fuel cut-off switch needed reset! Hadn't happen to me before with this truck, which I purchased 5/2019.

Truck cranked up and ran great for about 20 mins. FICM showing 48-48.5 volts while driving. I didn't record ICP voltage while driving, but did look it up at the time and found reading to be satisfactory. Truck simply shut off while driving after 20 mins...right at foot of driveway - thankfully. Waited for an hour, cranked right up and parked it.

Proceeded to replace IPR valve with new Motorcraft unit. During effort, found FICM was replaced in 1/2010 by FICMrepair.com. Found IPR pigtail faulty. Needed truck so re-assembled anyway without replacing pigtail (ordered one). Waste of time, as truck wouldn't start. Replaced IPR pigtail with OEM style unit from Accurate Diesel.

Reassembled and now crank, no start. Batteries read 11.6 KOEO and cranking strong (>160rpm). KOEO FICM 47.5-48.5 (varies, but not below 47.5). ICP 0.2 volts KOEO, and reaches .6 during start attempt, then shows .3 after attempt. FICM sync = 0 KOEO, then 1 during start attempt. Fuel pressure builds during crank (65psi on gauge; typically around 78 when running). Unplugged ICP to test and still no start (scanner reads 0 volts when unplugged KOEO & during crank). ICP pigtail is super clean - guessing it was replaced by prior owner.

Appreciate thoughts on where to go next. I assume more scan data is needed, but could use some guidance on how to do so (if appropriate). Thanks in advance.

 

Are you building injection pressure while cranking? Checked the dummy plugs and stand pipes for blown o-rings?

 

In addition to above...have you updated to the non-STC fitting at the HP oil T off the pump?

 

Thanks, guys. Ran air through system at ICP today. Could not hear any leaks. Troubleshooting began with 150psi of high pressure oil. After 1.5 hours of charge, crank, charge...pressure built up to 390psi. During the process, noticed that the oil filter lid was not completely seated. I must have made that mistake when checking the canister for oil a few days back. Today, I noticed the top of the filter was not saturated. Pressure began building after it was fully seated. I opened it after cranking for a while and the complete filter is now covered with oil. Suspect I have air in the system. Friend of mine recommends continuing the charge/crank/charge cycle for a while. Says they can be finicky if air has entered the system. He also recommends pulling plug off IPR and trying to start. Says that should open valve completely and, if the new valve is a problem, it will start and just run poorly. Legit?

I have not checked dummy plugs/stand pipes yet. I don't know if the STC fitting has been updated. Sounds like these are next steps. Appreciate your input.

 

Buddy called me back. Says he's reviewing old documentation and had to correct himself. IPR needs to be powered up to start. Believes its 85% duty cycle (~9V). Recommends I pull IPR pigtail and measure voltage while cranking. Since I just replaced that pigtail, seems like an appropriate test to ensure my splices are sound.

 

You need to build a minimum of 500 psi for a 6.0 to think about starting. Air may be some of it but you more then likely have something else that is bleeding off your high pressure oil if you can only build up 390 psi. If IPR reaches 85% it is fully closed and the pcm is doing all it can to build oil pressure.

 

I rebuilt a 6.0 recently for a customer. He brought all parts...from Sinister Diesel. All the orings were made in China in their kit...along with the standpipes/dummies. None of it would seal and allow the engine to build HPO. Everything was out of tolerance. I had him order all the orings and standpipes/dummy plugs from Ford. Truck started on the second crank with the real, quality-controlled Motorcraft parts. I also resealed the nipple cups for him, as his were leaking slightly. Had to go Motorcraft on those, too. His injector orings were toast when I pulled them as well... at only 130k miles.

 

Good feedback, thank you. Been continuing the charge/crank efforts hoping to burp and suddenly start. No luck with that easy approach. Plan to check voltage at IPR pigtail next, just need time to do so. I’m getting pretty good at pulling air filter, degas and FICM...If I’ve got voltage at IPR, must be leaking from somewhere. Will advise.

Since I did run truck a good 20 minutes without fully sealed oil filter lid, any thoughts on impact? Possibly related? Before IPR change (and oil filter lid mistake), it was starting without hesitation.

 

Monitor your oil pressure while cranking. You said you pressurized both sides of the HPO system with shop air (100 psi)?

 

Even if you drained the whole system, did a head swap, new injectors, or whatever, a few crank cycles will purge it enough to start so I doubt the cap incident is currently a contributing factor. I’m not sure about posting to outside sites but if you youtube dieseltechron he has a video starting with “ipr 85% testing” and it shows a real good example of troubleshooting hpop leaks and the ipr.

 

Ended up that my new Motorcraft IPR purchased from an eBay seller was defective. After a full month of troubleshooting, I was convinced that the IPR was not allowing proper pressure to build. Purchased a new Motorcraft unit locally and the truck fired right up. Thanks again for everyone’s input.