Questions about Exhaust Back Pressure Valve EBPV

The EBPV(Exhaust Back Pressure Valve) is the butterfly valve on the down pipe side of the turbo exhuast housing. It is operated by oil pressure, so with the motor shut-off it should be open. The PCM opens/closes it to help warm the enigne. I have never heard of someone wiring it open, but you could unplug the connector at the base of the pedestal to disable it.

Is the red hose you are talking about plugged into a little cannister that is bolted to the compressor housing? If so it is for the waste gate, which is controlled by boost pressure not vacuum. This I have heard of people wiring closed, it should be closed when the motor is off and until you reach a certain level of boost. Disconnecting the red line should keep the waste gate closed.

To me, neither one of these sound like your problem. I have unhooked my wastegate, and I have had a sticky EBPV before and neither one caused a lurching or shuddering. Do you notice high egts and/or low boost when it happens? If you hold the light throttle does it continue to do it as you pick up speed? If you give it more throttle does it go away? Does it go away after it is up to temperature? It doesn't happen to do it at a certain speed does it(35-40mph)?

[ QUOTE ]
Is the EBPV the valve at the back of my 99 7.3 turbo?

For over 60k miles I have been having a problem with a lurching, shuddering when the engine water temp has almost reached operating temp. Numerous shops have looked at it & verified the problem. There are no trouble codes.
...

What position should the EBPV be in at operating temp? Should it be in the same position as when the truck is not running?

It was recently suggested by an International mechanic to wire the EBPV open & see if the problem happens. Since the valve at the back of the turbo is vacuum operated, wired would mean to physically wire the gate open. Would I need to wire it opposite of the position when the truck is off?

What if I disconnect the red hose would that keep the valve open or closed?

Any discussion, explanation or description of the EBPV system would be appreciated.

Thanks

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The cable to the lever which turns the butterfly
open/closed on the EBPV is on the underside of the turbo. YOu
can see it better or access it better from the passenger side. It's
also more easily accessed if you remove the upper rubber hose on
the passenger side of the intercooler tubes. And prop that
aluminum tube up out of the way. Mine needed cleaning and
tightening anyway.
I just had a problem with similar symptoms, my truck
was also hard to start. My issue happened after my
EBPV sensor and the little tube going to it were replaced,
not sure if it was the mechanics fault or just bad luck, but
that cable can come off the EBPV vale. Truck ran great
for about a week, then...it ran worse than before. When
this cable came off, my EBPV valve
was flapping and I guess got stuck closed...arg..
I was searching this forum for ways to disconnect the
whole thing, etc...Then I found my cable was off...whoops..
That cable is spring loaded to the open position. Which
is with the cable shortest or I guess you
could say the lever to the valve turned towards the drivers
side of the truck, if that helps. I read on here,
(do a search, alot of good links) that when
the truck first starts the EBPV sensor causes the cable to
push the valve or lever, closing off the exhaust.
In my case, since it was no longer connected the Valve was free
to go to any position. Don't know if this could be
your problem, but take a look at the cable/lever to
make sure it's connected. You can also just push
the lever/valve to see if it moves or see
what position it is in.

Wally

I think that sensor does some other stuff too. Computer wise.
Which is why some of the posts had said not to
just disconnect it. Other folks said no problem...But, I'm no expert in the area. I think they were disconnecting it near the turbo though
or EBPV base/housing.
There was some talk in other posts of a bypass sensor/device you
can buy from an aftermarket vendor
which would eliminate any codes it might generate.
I paid the $400+ to have someone change it
and the tube from it to somewhere...Now I think
I could have done that myself..Oh well, live and learn.

Good luck! Let us know what you find out.

Wally