My 2006 diesel F250 SD is giving me problems and I am hoping someone can help me figure out what the problem is.

Current problem:
Last night I started my truck, put it in drive and pressed on the accelerator but the engine RPMs did not change. I repeatedly pressed on the accelerator and nothing happened, it just idled. I put it in drive and called someone to come get me. While I was talking to them, the engine revved up to about 1100 RPM then went back to normal idle and I drove it without any problems.


History:
About two months ago my idle started fluctuating. It would drop to 500 RPM and then go back and sometimes it would surge to 1100 or so without my foot on the accelerator. This only happens when I am in drive with my foot on the brake. And occasionally I would take off from a stop and there would be terrible turbo lag.

About a month ago I was out of town and the truck ignored the accelerator peddle again but did not fix itself. I had it towed to a Ford dealer and they said the EGR valve had stuck open and sootted up the turbo. They replaced the EGR valve and cleaned the turbo and gave it back to me. Two days later I was driving it and the idle started fluctuating again. I took it to the local Ford dealer and they could not get it to do anything wrong so they changed the oil, reprogrammed the computers and sent me on my way. A few days after that the fluctuating idle started back. I decided to ignore it to see if it would get worse. Up until last night I was getting the fluctuating idle every day and the bad turbo lag about once every three days.

Does anything pop out at you as a possible cause for this behavior? I am scheduled to haul my RV next weekend and right now I do not trust my truck.

 

I would be checking over the throttle peddle under the dash for a loose electrical connection to it. With the newer diesels (and some other vehicles with drive by wire) the electrical connection to the peddle if loose would not transmit the peddle movement to the servo on the throttle body (computer and injectors on a diesel). Possible the peddle assembly could be bad as well but I would check over connections first before throwing parts at the vehicle like dealerships like to do.

 

You could have a connection issue but I doubt it. Those weatherpak type connectors are pretty bulletproof. My money would be on the pedal assembly itself. Basically its a big potentiometer-like a dimmer switch. They do occasionally fail.If this ends up being the problem, they usually run around $100-$125 depending on the source.

 

Moved to the 6.0L Powerstroke Diesel forum.

 

Get the codes read. If the APP (or the wiring and connectors to it) are failing, there will be codes.

 

With the surging/idle fluctuation I would actually suspect an IPR valve problem, but as Dchamberlain said you need to get it scanned for codes. If it comes back with something like a P2290 or a P2285 it's a high pressure oil/IPR/ICP problem. If it comes back with something like a P2104 through P2140 it's a pedal problem

 

I took the truck to the local Ford dealer this morning and they called me about 4:00 and told me that they had replaced the exhaust back pressure sensor. I have only driven it twice for a total of about 12 miles but so far so good. The turbo lag did not show up and everything went well. I will keep you posted on how it does this weekend. Does a bad exhaust back pressure sensor sound like it could cause the problems that I was having?

 

Yes Sir, definitely. That EBP sensor has been the cause of several strange issues that I've seen on the forum in the nature of what you described. I thought you were going to say they replaced the ICP sensor, it can also do some of the same stuff.

Hopefully they got you taken care of and your weekend trip goes very well...

 

My truck preformed well this weekend. It pulled our 10,000 lb 5th wheel 120 miles yesterday and everything went as expected.

 

It looks like I spoke too soon. On my way to work this morning it came back. When I stopped at red lights, the low idle started and most notably the turbo lag came back. I will take it back to the shop as soon as I get a chance.

Is there a website that I can get a recommendation of a good mechanic locally that would be better suited to help me than the dealer?

 

Check the closest state FTE chapter to where you live. Usually someone there can recommend a good dealership close to your area.

 

I took it back to the dealer this morning and they finally got it to act up for them. They said that the injector pump seal is leaking and needs to be replaced. They want $58.28 for the part and $1,080 for the labor. They said it is a 10 hour job. It this correct?

I haven't turned wrenches in several years but is this something that an average Joe can do himself? Or does it require tools and equipment that most people don't have?

 

You could do it yourself. 10 hours is about right for that job (it took me 20-paid myself $25 per hour so I would come out ahead of the dealer's prices). Involves removing the turbo, but it's not too bad once you get in there.

 

The dealer ended up putting this through under my expired warranty because I brought it to them for this problem before the warranty ran out.

The receipt says:
Unrealized 5C3Z 9T287 B :Manifold Asy - Fuel Supply Qty:1
Installed 4C3Z 9B246 F :Kit

What does the word unrealized mean in this situation?

 

My best guess is that unrealized means they are taking the blame for not finding the problem as you reported it while it was still under warranty so that they can get paid by Ford. I'd bet not too many dealers know how to or would do this for a customer because of the paperwork involved. Sometimes you have to jump through hoops to get warranty payment and it's allllllllll about how you word things.