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2005 6.0L issue I can't pinpoint problem

2K views 11 replies 4 participants last post by  bbockstanz 
#1 ·
I am starting to beat my head on a wall about this issue. Quick history, truck is an 05 F250 CCLB with 6.0 stock engine, Banks pipe from intercooler to elbow and banks elbow, and 4" straight exhaust. Has almost 160k on it. a month ago, started having cylinder missing issues. Tried the fuel additives and did fuel filter change. Got worse(think changing the filter put more crap to injectors and caused it to get worse). Decided to just do all the upgrades now. So, had the engine tore apart and did Ford head gaskets, ARP studs, welded up the EGR cooler(tig welded at work), replaced all 8 injectors with Alliant injectors, updated STC fitting, and blue spring. Got the truck all back together and drove perfect and flawless for around 500 to 600 miles. Got 15mpg which I thought was great for the truck(factory cal). Took a trip last weekend pulling my travel trailer(8500lbs). Drove great for 3/4 of the trip flawlessly. boost looked where it should be, temps were nice, everything seemed great. Then, noticed boost gauge was quite a bit higher and engine seemed to be working harder. Got to destination and camped for next 4 days. When firing it up to leave, had blue smoke like it did before I did all the work because of the injectors originally and seemed to be working harder, even at idle slightly. Got all the way back home but still used more boost pressure then it did when it ran perfect. Blue smoke went away but seems to be down on power, and not running right. I took it to the dealership to have it hooked to the IDS for cylinder contribution and all checks. Everything checks out like normal. But, even the tech said the engine seems to have a miss feel to it and not running 100%. I don't know what to look for or at next. Any help would be greatly appreciated.
 
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#2 ·
I'm no pro but I think i would be checking EGR, EBP sensor & MAP sensor next...if the dealer didn't already do it.
 
#3 ·
The data coming from those sensors looks realistic. It's going back to the dealer(friend at the dealer) and he is going to take it and try to figure it out over the weekend. It's just not making sense to me at all what the problem could be. It seems like an injector issue to me but the balance/contribution tests say it's running fine. They are a reman set of Alliant Power injectors which shouldn't have an issue. At idle, it seems like the engine is loaded slightly like it's in gear even when it is in park. You can hear through the exhaust like it has one consistent miss/sound to it, but everything says it's running on all 8. Even when you shut off each injector at a time at idle, you can feel each injector turn off that corresponds to the one you are deactivating in the IDS so that says the engine is controlling all 8 like it should.

The truck would easily make 30lbs of boost almost all the time when on it hard, and now makes 23 to 25 in all gears at WOT except the higher gears where it is loaded harder and then it gets close to 30 but not like it did before. I'm just stumped with this. Also, on the return trip, I had problems with the boot at the turbo blowing off 5 times when it was reading 20lbs of boost in the intake manifold. I'm going to look for boost leaks or blown intercooler tanks but don't think this would cause the engine to have a slightly rough idle and run the way it does.
 
#5 ·
How about a blockage or a ton of oil in the IC or attaching hoses? Or a hole in one of the boots?
 
#6 ·
I just took all the tubes off and the boots. No tears and everything inside looked clean. I removed the exhaust back pressure sensor and cleaned it and blew air back through the line and could easily hear it in the exhaust. For the heck of it, I removed the belt form the front of the engine and started it in case something was dragging the engine down and that didn't make a change. I also opened the cap for the fuel filter, removed FICM relay, and cranked the engine with the engine bay crank wire and saw no bubbles in the fuel bowl. I then put everything back together and started it up. Still has a vibration to it. I have a surface temp gun and checked every runner on the exhaust and all 8 were within 10 degrees F. Even the turbo inlet had no oil on it. Even more baffled now.
 
#7 ·
No coolant loss?
I only ask due to the EGR cooler weld up comment. If the back end is exhaust plugged that stops exhaust but not the ability for cooler to leak and still get coolant into intake.

The other cuase that has stumped me and does cause blue smoke and "ratty" running is FICM. There is more to FICM than just the 48V main power issue. If an issue develops with a capacitor you can have 48 V but not the right drive current and also have "dirty" 48v injector control signals.
I have had a couple of trucks stump me with all the work that was done and they would smoke and just not run crisp and responsive. FICM rebuilds fixed both (I use Ficmfixer since he is near me and seems to have the same skills as Ficmrepair).
 
#8 ·
No coolant loss. The EGR cooler exhaust is welded up at both ends so even if coolant leaked into the cooler, it has nowhere to go because both ends are welded shut. I'm not sure about the FICM. The voltage is either 48 or 48.5. I can pick one up tomorrow and try it and see if there is any change.
 
#11 ·
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