Over the past month my 6.0 has done the following a few times recently on warm days after it's been driven. None are cold starts:

Engine cranks fine but it starts at a very low and rough idle (below 500rpm), then dies. I turn the key to off, wait a few seconds, and then try again. It will do this another time or two, then it will start and run. No smoke at all from the exhaust, no recent changes except the FICM was replaced in May, no tuner installed. EGR valve was replaced in October 2007 and has not been pulled since.

I noticed this AM that the idle rpm is varying slightly. It idles at about 700-750 rpm but the tach needle will drop slightly and the engine sound changes at the same time. No rough idle, no smoke.

Thoughts? I'm wondering if the HPOP is giving me a warning or if it's sensor related. No CEL and I've not checked for codes though I'll do that later this AM.

It also seems to run better when it's cold and the turbo lag has gotten worse lately, seems to be worse when it's warmed up.

 

Maybe your EGR valve is sticking open slightly? A couple of those symptoms sound like a leaking EGR flow. Maybe try pulling it, cleaning it, make sure it's closed when you reinstall, then unplug it for a while and see if the symptoms change.

At least the above would be a free first step you can do yourself.

 

Sounds to me like a HPO leak as it only happens when the oil is up to temp and thinned out.Have you noticed longer than normal crank times after the truck sits over night?Though if you notice any surging at all the ICP would be my suspect.

 

another vote to check the EGR.

 

Futzed with the EGR and could not get it to come out. Didn't want to screw it up so I took it to the dealer this AM.

Preliminary diagnosis: The FICM failed again. This FICM is a remanned unit which was installed a few months back after they reprogrammed the original unit. 3rd time is a charm, right?

 

i think it could be the FICM but when mine went out the truck wouldn't even start, not sure if that's normal or if it can go both ways... i don't really know much about the HPOP and how they work but what brickie said in his post makes since. also we both have '05s and my HPOP needed the STC fitting upgrade, maybe it's your time for that too. good luck!

 

Great point on the STC fitting. It just seems like it's electrical/programming related because it's intermittent. Having stated that I'll certainly ask them to check the STC because I won't be such a nice guy if my truck won't start and needs to be towed in for service.... especially if my trailer is attached to it and I'm 200 miles from this dealer.

 

It starts right up after it sits overnight. It starts right up most of the time when it's hot, too. It's just an intermittent problem, maybe once every 2 to 3 weeks so far and only when it's hot and has sat for 15 to 30 minutes.

It did it last week in the afternoon, when it died I shut the key off and immediately cranked it again and it started right up and ran fine. Even the excessive turbo lag is not consistent.

 

Sorry to hear Russ, might as well sign you up for FICM of the month. Quite a few of the guys here and other forums are going through FICM units like chicklets. The flash I have does not involve the injector buzz or heat induction as you would call it.

 

Sounds a lot like mine Russ. Mine was an injector/FICM combination though. Changed the injector because it finally threw a code then the dreaded FICM code popped up. Seems that all of a sudden there are FICM's going down everywhere. My parts guy sold 4 in 2 days. Had the tech run a contribution/balance test while he reflashed the FICM and he told me the same injector had gone out again. WTF???? I was told by a well known tuner that the inductive heating flash is extremely hard on the FICM's. Maybe it's Ford's way of recouping past warranty costs???

 

FICM of the month..... not the club I was looking forward to joining!

It just amazes and frustrates me that 6 years after this engine is rolled out Ford is still having problems figuring things out.

I have to stop by the dealer today and speak with the Tech. I'll ask about the STC fitting, contribution balance test, etc....

 

Case in point........7.3L cam position sensors

 

Is the inductive heat flash the current one or a TSB item that is added to a flash for cold start issues?

 

The inductive heating flash (at least for my 04.25) is the current flash. Had it done again yesterday. It's almost 2 years since I had it done the first time.

 

They're having trouble figuring it out. It's throwing a code but the FICM tests good. I'll stop by after work and get the code and make sure they've done the contribution balance test. I asked them yesterday to check the STC so I'll verify that as well. I want to see it verified on the final paperowrk so I'm covered should it fail within the year or so.

Warranty expires April 30th, 2010. A curse and a blessing.....