I'm looking for any advice or tests to try please. I own an auto enginuity with the enhanced pack.

I replaced the FICM about six months ago. Car has been great since then until today. I noticed that the idle was rising a falling just a bit, maybe 50 RPM. It was idling like this in drive or park. While driving the car felt a little lumpy. It still seemed to have good power if I put my foot down. Drove home.

Went back out a bit later and started the car, no more rising and falling idle.

I hooked up the AE. All the FICM voltages are good, 48.5 and 13.5, so can I rule out a FICM issue?

Could the FICM cause the intermittent rise and fall in idle?

What might cause the rise and fall? What else can I check with the auto enginuity?

I changed the oil a few months ago with Rotella synthetic and a motorcraft filter. I also threw in two bottles of rev-x.

No trouble codes stored. No dashboard warnings.

I was thinking about checking for water in the fuel by draining the contraption on the frame rail. I changed the fuel filter about 10 months ago.

Any thoughts?

Thanks so much,
Mark

 

Try checking the ICP sensor. Mine did this and ended up just needing to reseat the wiring connector to it.

 

Thanks I will check that in the morning. I have an 03 excursion. Is the ICP under the turbo? What does it look like?

 

Yes its under the turbo.


ICP101 Fuel Injection Pressure Sensor 04 07 6 0L Ford Powerstroke Engine | eBay

 

Thanks I just found a picture of the location. Could they bury it anymore?

Looks like I need to remove a few heat shields to reach it?

Did you reseat yours without removing anything?

 

I just unplugged it and plugged it back in. Probably wouldn't hurt to use some plastic safe contact cleaner and reassemble with some dielectric grease.

 

Well, after the rough running last Friday night, the X hasn't acted up again, which is good and bad I guess. I drove around all weekend with a laptop and the AE hooked up.

FICM voltage was good the whole time, ICP, ICPV and ICP% looked fine.

My guess is that everything will look fine on the AE until the rough idle comes back again. That's a bummer since my wife drives the car most of the time taking the kids to school and what not. I really don't want it to break down on her. She has no confidence in the car now. It had a FICM problem a few months back and she was just getting her confidence back in the car when this happened.

I tried jiggling the ICP harness around while the engine was running but that didn't change anything. I must say the shielding around the harness is very clean and shiny. I don't know if the PO changed it out at some point.

I am considering just buying an ICP and replacement pigtail and replacing it for the heck of it.

I did pull the drain plug on the frame rail for the water collector thing and drained out whatever diesel was in the lines. I didn't note any water.

Not sure if there is anything else I can check or test? It sort of sucks to just wait for this to happen again, especially since it'll most likely happen while my wife is driving it with the kids.

 

Anything ever come of this? I have been troubleshooting a friend's 6.0 and it has me stumped as literally all PIDs are reading fine, even when the idle surges.

I was thinking of swapping my ICP with his and see if the problem follows the ICP to my truck or even with the good ICP his still acts up.

Josh

 

Does unplugging the EBP sensor have any effect on the surging at idle?

 

I haven't tried that yet. It happens so fast and clears up fairly quickly.

The one thing is the RPM increases and the surging isn't decreasing rpm. With that I did notice the engine normally ran 22-23% however the second time it surged it briefly nudged 21%. I wasn't data logging at the time so it may have dropped further for the split second.

Pretty sure I'll get to play with it this weekend. I'm pretty sure it's the ICP or pigtail, 2nd I suspect the MAF, 3rd an injector and 4th the EBP.

Josh

 

Resurrecting my own thread.

I had a bad FICM replaced right after posting my original question. This seemed to clear up all the problems I was having, almost...

I started getting an occasional rough idle after a long stint of freeway driving. At the off ramp when coming to a stop, the idle would go up and down by maybe 100 rpm-ish.

I could never get it to stay long enough too hook up my AE.

These days, the up/down idle is getting more regular and I don't have to drive long distances for the problem to start.

X runs great otherwise, a little dark-ish smoke when first pulling away and when I get on it until maybe 45 mph. Seems to have plenty of power, maybe a bit slow to respond off the line. I see the smoke almost before she starts gaining speed.

I have an FICM Atlas 40 tune and figured that was the cause of the smoke but now I'm not so sure...

Should I start by trying to unplug the ICP? Can I drive around safely for a while with it unplugged?

Thanks!

 

Yes you can drive around safely with it unplugged. I had a simular issue, I installed a new set of injectors when I had my dorman oil cooler failure and rubber through put my hpo system. I have not had the issue since. It was never very bad bit it would have a on and off slight miss at idle after driving 60 plus miles. Do you have any cylinder Contribution codes?

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Yes driving around with icp unpluged will cause a loss in mpg, maybe some negitive performance but no damage that im aware of

 

Thanks! The AE shows nothing bad...

My wallet would not be happy about a whole new set of injectors.