Misfire like event under light load cold

[Tweeder]

I know, A misfiring 6.0 thread.

Here's my issue, I can't seam to find any other thread that seams to be what's going on with my truck. I believe it may be a failing injector, however nothing is showing up in the system. So, here's the problem.

When the air temperature and engine oil are cold (Under 180* engine, ambient air temp under 60*) my truck will misfire/surge at light throttle. occasionally i can feel a misfire at idle as well. truck warms, everything seams fine. The truck has also failed to start twice on me. Once in May, and the other time is just last week in September. Both times the engine was hot.

So, here's the rub.

Oil change: All new filters, all OEM. Fuel and oil
Valvoline Premium Blue synthetic 5w-40 oil
Last oil change I used Rev X This time, Hot Shot Secrets

Forscan: No codes at all. NONE.

Recent repairs: New ICP and pigtail
New IPR and pigtail
New glow plugs, harnesses, and glow plug control module
Dealership replaced HPOP before purchase in April
Both brand new batteries
New alternator

FICM: 48V all time Drops to 47v at start up
13.5v Logic never drops below 13v
13.5v vehicle power never drops below 13

ICP: 1.61v-1.77v at start up, settles in at .80v-.90v after idle established
1264psi at start up, 590-620psi at idle

IPR: 42.97% at start up and settles in at 30% give or take at idle

Mode 6 shows zero misfires. Driving or otherwise. Even when the misfire happens.

PCM shows no misfires, shows no contribution codes, no fault codes at all. The only oddity is the fan speed. It's always flat. Shows 0.00% at all times, however it does show rpm on fan. I know the fan spins, because I can hear it, and see it. Could this be causing this issue??

Truck info: 2005 F250 192,000 miles Auto trans. NO performance mods, EGR cooler removed (Valve still in place), bone stock otherwise. No coolant loss, no oil loss, no smoke (except that diesel off idle black puff). I'm completely at a loss, I have no idea where to look from here. I can't imagine the fan could be causing a misfire like feeling? But maybe it's cycling on/off too randomly and putting a draw on the motor? If that's the case, it's just strange that it only happens when it's cold. I really don't want to start throwing money at it, but I'm not sure what else to do.

I'm thinking about taking it to the dealership for an IDS scan, just not sure they'll find anything either. If I do take it to the dealership, I'm going to request a contribution test, and a high pressure oil system pressure test, but anything else I should ask for? What Might I be missing? The thing runs like a raped ape otherwise, so I'm completely lost.

 

[sootie]

Watch the power balance real time in forscan when the issue occurs

 

[Tweeder]

What's the power balance listed as?

 

[Tweeder]

OK, So I believe I may know what's going on. However I need some more info as google and these forums are not giving straight answers. I did a running diagnostic, and I'm getting a high IPR I believe. I did a WOT run watching my ICP and IPR and my ICP is pushing 3924, IPR 76% at 3400 rpm. That signals a hpop system leak correct?

 

[lincolnlocker]

Are those original injectors?

live life full throttle

 

[bismic]

3924 psig maximum HPOP discharge pressure is pretty good ...... Doesn't sound like a bad HPOP or a high pressure oil system leak to me.

 

[Tweeder]

Are those original injectors?

live life full throttle

I have no idea, I've only owned the truck since April.

 

[Tweeder]

3924 psig maximum HPOP discharge pressure is pretty good ...... Doesn't sound like a bad HPOP or a high pressure oil system leak to me.

That's good to know. Thanks.

 

[Tweeder]

Decided to bump this thread myself, since I'm still having the issue, and it seems to be getting worse. Tends to be really bad when the air temperature is cold.

So, here's new info. Keep in mind I have no codes of any kind at this point. Forscan, AE, Ford IDS, and Snap on Modis all show zero fault codes.

Ae, IDS, and Snapon: none show a misfire, all three show all cylinders operating within 3% of each other with contribution/power balance tests; even during the event.
Replaced both camshaft position sensor/pigtail, and crankshaft position sensor/pigtail.
Took it to a transmission shop thinking maybe torque converter lock up was the issue, nope. Transmission checked out also. All pressures were good, no pieces of anything in the pan, no unusual particles inside, tested all of the valves, everything came back perfect. Changed filters, and did a flush just because they were in there.
Did the "bubble test" in the fuel bowl, so I know an injector isn't leaking into the fuel system.
Fuel pressure steady at 68/69 even WOT.
Boost never fluctuates.
RPMs remain steady
Speed remains steady
MAP and BARO are same koeo, and very close koer.
Checked the line from passenger side valve cover to MAP and it's clean and clear. Same with the EBP sensor and tube.

I know it's something with the engine, just not sure what. I can hear the engine "pop" out of the exhaust when the event occurs. But the computer won't show me what it is. Any ideas at this point are welcome. Driving me crazy!

Again, I have no smoke, and no loss of fluids.

Could a bad air temperature reading cause this without showing a code of some kind?

 

[bismic]

Still sounds like an injector

Were the new ICP and IPR parts OEM or aftermarket?

 

[6.0 Tech]

Is the egr still intact? Ive had a couple that kicked my ass for quite a few days that turned out the egr valve was fluttering under the correct conditions and caused what felt like a misfire.

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[bismic]

His EGR cooler has been removed.

 

[6.0 Tech]

His EGR cooler has been removed.

Whoops, missed that part...

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[lincolnlocker]

Bent push rod

live life full throttle

 

[ghohouston]

Is the egr still intact? Ive had a couple that kicked my ass for quite a few days that turned out the egr valve was fluttering under the correct conditions and caused what felt like a misfire.

Sent from my VS988 using Tapatalk

I too have experienced that on a few 6 0's throughout the years.

 

[SoGrand]

Bent push rod

live life full throttle

:whs: Or lifter going bad or i could say camshaft wore down from lifter.

 

[Tweeder]

They were ford OEM. I'm down to thinking about replacing all injectors and the ficm at the beginning of the year. Without any codes, and with the power balance test not showing anything I'm kind of just throwing darts at the wall at this point.

 

[Tweeder]

Bent push rod

live life full throttle

Why would it only happen when engine is cold though? I understand your point of suggesting this, but only when cold doesn't make sense to me.

 

[Tweeder]

Let me ask another question too. How fast are your 6.0's building boost?

Off a street light; from idle; if I smash the throttle to the ground, the truck is quite laggy through say half the intersection, then it builds boost fast and sucks me into the seat. But that first 50' or so there's almost no power.

My first 6.0 experience, and I know the turbo on the 7.3 made it lag from a dead stop, but I thought the vgt was supposed to solve this issue. But my buddies 6 speed manual 7.3 has more 0-20 acceleration than my 6.0 does. Could a vgt solenoid go bad without throwing a code? Maybe I need to rebuild my turbo?

I'm starting a new job at the beginning of the year where I'll have a company vehicle; so I won't need my SD as a daily commuter anymore. I'll have time to do some of the more extensive searching. I've been kind of limited to a day here, wait three weeks and have a day, wait a month and have another day kind of searching.

 

[79jasper]

The unison ring/veins could be sticking.

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