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I have a stock '05 6.0 with 260k and just about rebuilt (hopefully) everything that there is to rebuild over the last 3 years: EGR delete, air intake, Y pipe, radiator, all injectors, glow plugs, stand pipe, dummy plugs, EBP sensor, ICP sensor, IPR, turbo. I am sure I have missed something but hopefully you get the picture. I have a ScanGuage so can monitor whatever is needed. Last pieces to be replaced are the turbo and EBP sensor 2 weeks ago and I am now left with the following symptoms: I live at 8900' and drive down to work each day to 5000'. Up where I live everything looks and drives great - turbo spools up/down (max BST low 20's with no trailer), VGT cycles from 50% down to 15% at idle, EBP reads from 15-30's. Truck drives normal. When I get "downhill" VGT tends to stay in the 50-60's range and my boost stays at high teens minimum and spools up above 30 (I have seen 35) on the slightest of inclines. The truck doesn't feel like it has as much oomph as normal and struggles to keep to 75MPH. I go to work, let it sit all day then drive home - it drives and acts normal (at least the last couple of days) all the way home - cruises at 75MPH NP. I haven't looked at MAP or the barometric pressure readings but is feels/seems to me like something is not adjusting for the change in altitude? Can the MAP sensor exhibit these symptoms or can the BARO sensor mess things up? I might be completely off so any suggestions are welcome.
Cheers,

Ian
 

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Discussion Starter #2
Update - for what it's worth

I was monitoring EBP the last couple of days and I typically stay under 30 (Scangauge) - what I noticed today was when I got down to lower elevation my EBP would max out at 50 and it feels like I am towing something (obviously as the back pressure builds up) and my boost then starts to jump up to 33/4/5 on slight inclines or acceleraion - presumably to compensate for the back pressure. The only other thing of note is that MAP pretty much stays equal to boost - I would have thought that MAP would be greater than boost though?
For testing sake I pulled over turned the truck off, started it right back up and everything went back to normal? So it looks like whatever is causing EBP to increase is my problem - is my cat backing up - I don't think that this year ('05 Excursion) had an exhaust valve as did earlier years - if it why does turning off/on reset everything? Do I have an electrical problem? Perhaps worth flashing the truck ?
 

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I don't know the stroller well but here goes.
I wouldn't think you would have an EBP gauge unless you did have an exhaust flapper.
Other vehicles run a different time map above a certain elevation. I'm sure Ford does too.
First, check that the baro is changing with elevation.
Second, check the exhaust flapper position sensor. It may not be telling the ECI that the flapper is closed. The flapper does a sweep on startup supposedly to check the sensor. It also helps keep carbon from causing it to stick.
 

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Thanks for the feedback jasong - the EBP reading is coming from the ScanGauge which is reading it from a EBP sensor that is (I believe) connected to the exhaust pre-cat - I think that there is not an exhaust flapper on this year - I believe that there was was on prior years but not '05 - I did verify that the baro is changing with elevation so that looks to be good.
Drive this AM - everything worked just fine ......
 

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Sorry for the late response.

None of the 6.0L years had an exhaust valve.

All years have an EBP sensor although the early 03's that were re-programmed (re-flashed) after 04 had the EBP sensor input deleted and an inferred value was used. Again - this was ONLY for the early 03's. Your 05 has and uses the EBP sensor.

MAP should always equal boost + Baro.

Make sure your MAP sensor hose is not cracked or plugged up. Also check the nipple on the manifold for plugging.

Also verify that your EBP tube is not plugged. You can get a large diameter weed-eater string and run down the tube.
 

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To me it looks as if your turbo vanes are sticking...especially when you mentioned.... VGT cycles from 50% down to 15% at idle...normally it should cycle between 85-15% back and forth in stages at idle, if it's not, then the vanes are not fully sweeping from open to close and visa versa. This was programmed in years ago in all the factory programming flashes to sweep the vanes at hot idle in order to decarbon the vanes and keep things moving freely. If the vanes are sticking it would also explain your symptoms.

Harry
 
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