I am posting this for my step-dad. Truck is a 2009 F250 6.4 automatic.

While driving to chicago, about 30 minutes from the airport he went to pass somebody, and when he stepped on it the power just went away. He said his speed dropped. It started running rough. He let up and it smoothed out. At idle and low amount of pedal it runs ok, but he said under moderate acceleration it acts up.

He flew out of the country, so when he gets back in 10 days, he'll need to figure out if its a simple fix or if he need to take it to a shop.

I don't know a whole lot about the 6.4 so I thought I'd post here.

Thanks in advance for any info you might have!

 

Well, a few questions first.

Is it stock? A plugged DPF will cause the condition you mention.

Do you have a way to monitor PID's? If so, what kind of fuel pressure readings are you getting?

Any smoke while running? If so, under what conditions does it exist?

 

Yes it is stock. From New Mexico until this summer. It has less than 100k miles, not sure exactly how much right now.

He does have Torque Pro. I don't think he was using it at the time, and won't be able to check it until he lands back in Chicago.

He didn't mention any smoke, but I will verify with him.

 

I know with the Edge Insight I can monitor the Exhaust Back Pressure. I would assume you can do that with Torque Pro. That should show if the DPF is partially plugged up. What I noticed on my truck when monitoring both Boost and EBP, they do run pretty close together. At times the EBP will be higher, but once boost starts to build, there isn't much difference between the 2.

 

Just a shot in the dark here but could one or both of the fuel filters be all but clogged up starving the engine of fuel?

 

Yesterday I was at my buddies shop and a customer came in with a 6.4 that was running very sluggish. The Exhaust Back Pressure Sensor was reading 88 lbs of back pressure with the truck shut off! Replaced the sensor and that was the fix!

 

I thought about fuel filters too.

He said no smoke, and no CEL.

 

CampSpringsJohn has a very good point on this. I have read in these forums about the EGT and backpressure sensors doing just that, I have also experenced the same happening with clogged fuel filters but not on my F350 So i cannot comment on which way to go except having both checked out. What I can say if this is even revelant to the subject is I got ahold of some bad fuel awhile back, I never had a water issue till then and during that tank was constantly draining water off, and also i think the fuel quality was also bad, since my regen cycle seemed to keep kicking in every 50-100 miles and it never did it that frequent prior to this tank, and kept on about every 150 after that till i changed out the filters, but as soon as i did, it was almost 400 miles before my regen kicked in, and has been about 230 since then. so maybe there is something to this, maybe not but its something to think about

 

Jaynik123 I'll keep that in mind. I kinda doubt it though because it was fine for the first 2 1/2 hours of driving on that fill up.