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Discussion Starter #1
Hi new to this forum and any help on this issue would be greatly appreciated. I have 2008 f250 6.4 I bought from Texas. It has the EGR delete and DPF delete done to it already and I would guess it has some sort of tune done but I do not know what. I was very shocked when I first got the truck at the amount of power it had. I called it my sports truck. We had some work to do to it right away we put a plow on it and had to redo the bed plate gasket leak. All of that went seemless (luckily I have a buddy with a shop, though he is not all that familiar with diesels but he is really sharp so we figure it out as we go along the way with help from forums like these). All was well for about a year standard oil changes and fuel filters. All of the sudden one day while in a drive thru the truck just shut down. It would not restart for a minute or 2 but then finally restarted, but in limp mode. So I quick ran over to their shop and my buddy who happened to buy the exact same truck a month after I did stated water in the fuel. So we opened the pet cock and I drove it out and everything was good again. The next day bam truck shuts down again same exact thing so I get where I need to go and drain fuel, limp mode goes away but I seem to have a slight loss in power. It is just a slight loss and only under heavy acceleration. This has been happening for the last 2 months. I figured the problem would get worse as we move along and in the meantime I replaced the batteries and alternator as a battery did fail and a bearing was making noise in the alternator so I didn't want to take any chances. I was hoping it was a charging system issue with the computer however nothing changed. The problem is in fact so slight that anyone else who drives the truck tells me it is fine. Here is what I got 1. Upon flooring the truck used to shoot right up to 40 pounds of boost, now it seems like a struggle to get over 30. 2. It will still go to 40 pounds of boost but only at low rpm for example rolling down the freeway and throw a 1/4 throttle down and it will get up to 40 pounds however it shift and create heavy acceleration even at 60 mph it will still not go over 30 pounds. 3. There seems to be a slower response on the turbos or more turbo lag than before. 4. This truck used to roll coal when you stepped on it a nice even path of black smoke coming from the tailpipe. Now it still puts out some black smoke but its very uneven based on rpm and not nearly as much. No codes are present my buddy had it hooked to a computer and drove it all around said everything is normal and the truck seems to be operating normal, however he understand that I have been driving the truck for over a year and that there is something to be said for knowing your own vehicle. He says the only thing we can do is wait for the problem to get worse, but I live in Wisconsin and I know what is going to happen. The problem will cause the entire truck to shut down and it will be in January on the side of the freeway when the temperature is 25 below zero and 50 mph winds. I have failed to see anyone with similar problems anywhere on the web and I have been researching for months. The closest one I came to was the downpipe gasket on the turbo however his problems seem to include a whistling under the hood which is not present here, any feedback would be greatly appreciated before I end up freezing to death on the side of a freeway trying to get the truck to refire, thanks./
 

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Check your EBP Sensor, map sensor, and baro sensor. Also try cleaning your MAF with actual Mass Air Flow Sensor cleaner, do NOT use brake clean or carb clean or contact cleaner. These sensors are very sensitive.

The 6.4's heavily rely on these sensors to control the vanes/boost of the truck.

Your baro sensor should be a constant pressure (your locations atmospheric pressure). If it show's zero, then you have a baro sensor issue.

Map sensor will show pressure at idle, then increase as RPM increases. If it doesn't change or show's zero, then that may be a problem as well.

Pull the EBP sensor out and replace it and the tube (or clean the tube thoroughly) and see if that helps it out.

It doesn't sound like the normal EBP sensor diagnostics, but it could have something to do with it. I see trucks have EBP sensor issues (when the egr is removed) when the colder months come about. Moisture and soot develops in the tube and clogs that tube up which throw's false readings.

Wouldn't hurt while your in there either to visually check the under hood fuel filter and frame fuel filter versus just draining it.
 

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Discussion Starter #3
The fuel filters are all fresh as I thought of that as well. I will check and clean according sensors and report back, thank you.
 

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The fuel filters are all fresh as I thought of that as well. I will check and clean according sensors and report back, thank you.
No problem! If your friend owns a shop, he should be able to hook up his scanner to the truck and run a live feed checking the map and baro sensor.
 

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Discussion Starter #5
update I cleaned the MAF MAP and IAT2 sensor. This made the truck run rough for a few miles but then adjusted accordingly and really seem to make the truck run a lot smoother. However this does not seem to have changed the turbo boost lag, and weird operation. I will be cleaning ebp next and we will see how that goes.
 

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update I cleaned the MAF MAP and IAT2 sensor. This made the truck run rough for a few miles but then adjusted accordingly and really seem to make the truck run a lot smoother. However this does not seem to have changed the turbo boost lag, and weird operation. I will be cleaning ebp next and we will see how that goes.
Question, what did you clean the MAF with?

Any update?
 

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Question, what did you clean the MAF with?

Any update?
I too have a similar issue to this in my 2008 Super Duty with the 6.4L, same deletes, etc.. I would appreciate an update on anything discovered. My truck is not throwing any codes and I have cleaned the MAP and IAT2 sensors, the MAF sensor and have installed a new EBP sensor. Thanks!!!
 

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The last thing that the discussion starter said that he was going to do was to clean the ebp, and he has never been seen since; so presumably that fixed it. You say that you have already installed a new ebp; so check to make sure that it is installed correctly and that you used the right part.
 
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