About 2-3 months ago, I bought a 2001 f350 with the 7.3.
when I bought it I would not get ANY turbo boost till atleast 2000rpms, and it would max out at 10psi, then it dropped to 5psi at 2500 rpms
.

I removed the turbo to find that nothing was wrong. (But gave me reason to install wicked wheal )

Now the Boost droped to nothing

.
I took it to a local dealer, they are telling me it is the EBPV and that would would cost $1,400+$150(diagnostic feas). They told me the part (turbo perch) is $750.00. But I am a mechanic so this doen't bother me(too much).
My Question is HOW IS THIS POSSIBLE?
The way he told me is that the exhaust is blowing the EBPV wide open, then is just goes straight down the down pipe. But I thought that any restriction in the exhaust would limit the how much and how fast the air is going through there, and THAT would limit the tubo wind up correct.

So basically I am just asking how the EBPV works, and why? (I always thought it just restricted the flow to help with warmup.) I would also like to know how to verify this? (I NEVER expect my customers to buy an expensive part withought showing it to there face, and telling them "I am 100% sure it is the problem." I would like to do the same for myself now so please help. I want my turbo back

 

I would think it would be more of an issue with the EBP tube? Rather than the actual Valve, just my .02 though.

 

Here is how I understand how the EBV (exhaust back pressure valve) works. When you have a high boost built up and let off the accelerator, boost builds up even more than it was before you let off (the engine is not using as much air). The only options at this point is to have the air go back through the intake wheel, or shut off the pressure to the exhaust side so that you quit building boost. The EBV does this by shunting the exhaust gas (combustion by-products) around the turbo, allowing the turbo to stop building boost on the intake side. If your EBV is malfunctioning, it is allowing the exhaust to bypass the turbo without going through it even when you are not building excessive boost. If this is the case, you would have a properly functioning turbo that would not build boost because of the EBV.

As you can see by my post count, I am a relative newb, so if I do not understand properly and have erred in my description, I would ask that some of the guru's correct me.

 

I know that if your EBV tube or sensor are clogged (pretty common) your truck will feel less powerful, I know that the EBPV is used primarily for cold start situations and many on this site remove or gut the EBPV. The descripiton above sounds a little more like the wastegate? which imho would also create a low boost situation of not properly adjusted. No expert either, just trying to help where I can and learn where I need too.

 

You have described the wastegate, not the EBPV. The EBPV is a butterfly valve the closes in the exhaust outlet to increase backpressure on the engine to help with warm-up. Many of us simply gut it, remove the ***'y in the pedestal, and plug the hole in the pedestal. Here are a few pics to help out:

EBPV in exhaust outlet (van & truck):


Wastegate in exhaust housing:


Gutted & plugged stock turbo & pedestal:

 

Izzy351 Thank you for the pictures, I have already had the turbo out and the ebv is moving freely, so is the wastegate, but the wastegate has a VERY strong spring in the banks big head holding it closed.
I am just really confused on how the exhoust is blowing the EBPV open and that is causing no turbo. If other peaple are gutting them out, and not getting any turbo loss, then how can he blame this on the ebpv? My only thought is that he is backwards, and somehow it is getting restricted maybe?

 

Yeah, it would be more like a restriction. Do you have gauges? It would cause skyrocketing EGTs if that thing closes when it's not supposed to. I'd just gut the thing. It really doesn't do that much for warm up anyway....

 

I have banks boost guage and egt guage. When getting on it, my egt goes to 800 easily, and when i really get'er goin I pass 900 easily.
When I get on it, I mean 3/4 to full throttle and 2,800 up rpm's (Truck is 6 spd manual), I usually do that when passing, or just to hear that little "squeak" of my turbo trying to go. It is really sad.

 

Ya, but your from texas, I am just outside of chicago. I have driven trucks through texas, but never in the winter, so I don't know how cold it gets down there, but comparing summer to summer, when we have 80 deg days, it was 110+ down there.

 

Izzy is right. That dealer that told you 1.400 dollars should have his or her head examined, if it is open it will not cause loss of boost, you need to look for leaks in the IC pipes or the up pipes or some where, stay away from that dealer please!!!

 

I went to the only other dealer in town, and he was trying to tell me that everyone gets it mixed up on these turbos, and that the wastegate was the one on bottomn, and the ebpv is the one on top. But I had already had the thing apart at that time, and so I knew he was wrong. I am running out of places to go.

 

I am going to put my shops scanner on it tomarrow, what would normal egt and exhaust back pressure readings suposed to be, This will help me beable to tell what is going on inside there. That is a big problem I am having, I do not deal with the deisels, so I don't know what my computer reading are supposed to be.
When I hook up to the map sensor hose, I should be reading positive pressure right? Because many times, this thing is reading a vacuume.

 

Good call up-pipes and IC pipes..................... If you haven't done the ccv mod check for oil leaks around the boots and black around your up-pipes around the pipe to collector area...............

 

There is a little bit of black on the driver's side firewall, it is pretty much even with the valve cover, and seamed like oil, so I assumed it was just blow back from the valvecover or pcv.

What is the ccv mod?
sorry if I am asking alot of questions, but I am new to owning and maintaning a deisel, but that is part of why I got it, to learn more about it and how to fix them.

 

Crank Case Vent mod.................. you reroute your crank case from venting into the intake of your turbo........... then vent it out the back of the truck................. this gets rid of oil in your IC pipes and the possability of your boots getting oily and slipping off...............

you can also make an adapter that attachs to your intake ,so that you can hook a compressor up to and blow compressed air into your IC pipes and listen for air leaks.............

I have a wickedwheel and turbonetics ebv delete and run 29 psi.....

How do you have your boost gauge hooked up?