Hello everyone, first I want to say thanks to all members of FTE for all of the information that has helped me along the way. I've solved many problems from reading these forums. This time I need a little help !

I have a 2001 7.3 with no modifications and 115,000 miles. I have a Bully Dog programmer but am currently using the stock programming. The problem I have is the truck seems lethargic once the engine comes up to operating temperature. When I first start it up and pull out of the driveway it seems snappy and accelerates and shifts gears pretty quickly. Once it warms up it seems like there a rag stuck in the airbox or like I'm pulling a trailer. It is most noticable at RPMs above 2000, just cruising it feels fine. It seems to run fine otherwise. And don't get me wrong, if anyone got in it and drove it they wouldn't feel anything wrong but I drive the truck everyday and know it feels different. This has been going on for a very long time it didn't just happen, I blamed the winter fuel, cold weather, etc but all those variable aside there are times when the truck seems fine so the lack of consistency rules out the weather/fuel. The warmer weather made it worse.. As a note this truck is my daily driver. I don't tow and dont do any type of heavy work, just normal yard/recreational stuff.

What I have done so far:
1) cleaned the EBPV sensor and tube
2) Once it was warmed up I disconnected the EBPV plug from the pedistal base.
3) removed the 4 turbo boots, checked for holes, cleaned and reinstalled.
4) Checked the EBPV valve to see if it was stuck by moving the arm, was ok.
5) Plugged in my programmer and the only codes that appear is the 0475 (EBPV disconnected, I unplugged it) and 0541 (intake air heater, which I removed).
6) I have changed the air filter, fuel filter and oil recently.
7) usually I have 35" tires but have put the stock tires/wheels back on because its easier to feel power differences as I try different things. As a side note my mileage seems to be good, 14 mpg around town, so I can't complain. I keep it below 2000 rpms.

I suspect the EBPV valve even though it is unplugged from the turbo base is openening when it shouldn't, can this happen ?

Also a question, is there a way to determine if my transmission is slipping a little when it warms up? This could also yield the same symptoms.

thanks in advance for any help!

 

short and simple, yes the trans could cause that, but it is going to take a capable scanner to diagnose it. www.autoenginuity.com

Unplugged the EBPV should not be closing unless there is an excessive amount of play in the rod.

I'm still thinking on "Sluggish when warm" - Just to be sure check the IPR and ICP connectors for tightness and corrosion on the pins.

 

Thanks for the response, I checked both of the mentioned connectors and they look fine. I am really at a loss here what to check next.

 

I hope you find the problem soon, my 00 acts the same way.

 

I found the problem. This seems not to make sense but here it goes. I already had the EBPV electrical harness on the turbo pedastal unplugged. I then cleaned the EBPV tube on the front of the engine and sensor. The tube was completely plugged with soot at the top right under the sensor. I put it all back together and noticed the problem was worse (yeah I know ????) I then pulled the plug from the EBPV sensor on top of the tube so it was disconneted. Bingo, the truck runs perfect, hot or cold. I suspected the exhaust valve was opening when it shouldn't have but I thought unplugging the harness from the pedastal would disable it. The sensor on the tube seemed to cause my problem. With both unplugged all the power is back, the truck doesn't sound like its laboring and my fuel mileage has been awesome. It doesnt make sense but maybe if the sensor on the tube was bad it was causing the PCM make some crazy adjustments? Anyway my problem is gone !

 

Bad sensor making the puter unhappy?

 

With a bad or disconnected EBPS the computer will disable the EBPV.

 

Yes, I was sooo close to gutting the EBPV but disabled and running so well I think I'll spare it ! Thanks for the help! Now I can address the bit of oil I found in the valley while I was cleaning the boots. I'll post what I find later, its not the pedastal. I need to investigate more with my inspection mirror. Man let me tell you how happy I am this thing runs well again. I've been dealing with this for a year now until I got on the forum and got ideas on what to check. Thanks to everyone.

 

Are you sure it oil? a leaky drain valve mixing with grit in the valley can look like oil.

 

Well, the leak is definately motor oil. It is running down the top of the tranny and onto the starter bolt. Not dripping on the ground YET. I thought it was the boots leaking but I replaced/tightened them. I then used a mirror and saw the EBPV valve arm, it was dry and clean, the peadastal O rings and bolts were changed 50,000 miles ago because they were leaking and the base looks dry and feels dry, cant see everything though. It apperars that the metal cover that fits over the intake that the lower side of the orange boot connects to is leaking where it mounts to the engine. There must be a gasket in there that cut loose, is this common or is this likely, heard of it before ?? I am going to need to completely clean the oil and see where it starts to get wet again. Also the small meatal tube that bolts to the back of the engine is very dirty, but does not appear to be leaking into the valley ot leaking at all its just sooty, grimy, but its wet. Hmmm??

 

what I should be looking for here? This is exactly what is happening to my truck.

 

Ok.. update.

I removed the EBPS tube and it was totally clogged at the topside mounting bracket. the sensor was totally clogged too. I cleaned it per guzzles page instructions put it all back together and no change.

I will now go and unplug the EBPS and see what happens.

I looked for the EBPV but could not see it. Do you have to remove any parts in order to see it under the turbo?

I also checked the rubber boots for the up pipes and all 4 were tight.

Sounds like a bad sensor but I will update in a bit.

Thanks...

 

ok... update .. unplugged the EBPS and there was no difference in power. It feels like no boost. I can hear the turbo (or "drone" noise) but no boost feeling.

I am at a loss.

 

Its been a while... but does anyone have any thoughts on this ???