Greetings,
Been on this site for a while and generally got the answers I needed. Retired now so I have more time to get involved.




I'm in Orlando FL, I bought a 2000 excursion 7.3 2wd with 240k miles in 2016. It came with pro comp 6-inch lift, ts chip. new tranny and driveshaft. The previous owner said whatever you do, don't use the #6 setting or else I would be buying the same. I did the hutch and harpoon mods, pre-pump airdog filter, new injectors, starter, alternator. Put new 2015 front end, Morimoto XBs, road armor stealth front, and rear bumpers, amp xl steps. She is gonna be Raptor lined black in a week or two. Installing 2016 King Ranch interior hopefully by christmas.
She ran great till last year when the heads went out around 350k. I put a reman from ford (hate the paint everything all black) in January of this year and she ran great for 600 miles till two days ago. Suddenly she is hard starting with the dash oil gauge not reading until 5 or 6 long cranks. With the engine being new, batteries a few months old but good, oil level good, hpop level good. Put multimeter to glow plug relay and it read 12.7, turned the ignition on and it didn't change so I replaced GPR. It started after the second try this morning. I have the auto enginuity tool but just learning it.
1. what live data readings should I set to give you the necessary starting info?
2. side question- she shut off at low speeds and idle after I put the reman in. I replaced the IPR, CPS, and ICP to rule out but to no avail. So I jumped onto engine bay, this time with cheater glasses and found a ground wire from driver side engine block to intake heater which obviously goes to relay. Not sure if that was a coincidence, but the problem went away. Would that be the cause?
thanks for your time

 

You using the 22 year old engine harness on your new engine?

For starting, you want to monitor:

- battery/system voltage
- IPR %
- ICP psi
- injector pulse width
-fuel pressure
Fuel pressure, unless you have installed a gauge in the cab, will have to be done manually with a gauge setup off the rear of the fuel bowl. Fittings (there are two) on the bowl are -4 ORB. You can use the same hose and gauge to connect to the top of the HPOP reservoir and monitor your low pressure oil while cranking AND until the oil warms up fully. I recently had a customer with a bad LPOP that created hard starting and two blown turbos. Oil pressure was only 18-20 psi on cold engine, and once the oil warmed up, that dropped to 5 psi. He went through two turbos before he brought it to me.

 

NicMike,
thank you for your response, I thought about getting that delphi harness when I got the relay but wanted to see if I should stick to oem. So upon running live data, I got KOEO;
ICP duty cycle 14.8
ICP volts - .25
Battery - 12.4
KOER;
IPR duty cycle 8.59
ICP volts - .84
RPM- 684
ICP - 482.50
Battery - 14.1
exhaust back pressure - 15.33
engine oil temp - 153.50
i will research the fuel and oil pressure installs this weekend. I hope the problem is as simple as LPOP, though rare on a new engine I would assume. would it not be a PCM or IDM issue?

 

Don't need ICP volts. Need the psi while cranking. Especially when it won't start.

Not saying your LPOP is bad, I'm just pointing out that it needs to be checked for how much psi it is putting out when it won't start by giving you an example of something I saw recently. His was hard starting as well, and the engine was not getting enough lubrication for the essentials while it was running....turbo, main bearings, etc. His had a fresh rebuild by the previous owner who was not a pro by any stretch. You are correct in assuming LPOPs go bad rarely, especially on a new engine. But engine builders can make mistakes, and I have seen a couple of bad LPOPs in my time.

My engine harness was replaced only a week ago after 21 years in the truck. The wiring was literally falling apart. Insulation was baked off in several places inside the plastic loom. It was causing several issues, to include dying in the middle of the road randomly and running rough/"missing" while driving down the road. New harness from Ford, and it is running like new again. The engine harnesses for the 7.3 are still being made in Mexico, and they are running ~$500 right now...down from ~$1000 a few years ago. After 22 years and 350k miles, yours is likely due like mine was.

When starting, your IPR duty cycle should climb in percentage open/closed while your psi goes up with it. Once the psi hits 480-500, it should start. The IPR % should drop back to the 15% range right after firing off. If it climbs and climbs and psi does not go up with it, there is a problem with high pressure oil bleeding off in the heads, IPR valve, injectors, or pump itself. Your system voltage should never drop below 10 volts, or the computer will shut down and not order the injectors to fire off. Do you have any codes stored in the computer?