VVT issues?

[DZL JIM]

VGT issues?

'07 6.0 that we cleaned the turbo and did the EGR delete, and now it seems the VGT doesn't want to shut off.
If I unplug the VGT wires at the turbo, the whoosh goes away. Plug it back in and it whooses.
If I unplug the EBP sensor, the sound stops, plug it back in and it whooses.

IDS turbo test operates the VGT perfectly, from closed to full open to closed, so I'm pretty sure the issue isn't at the turbo. ??

Any ideas what to look at next?
Could it be a bad solenoid ON the turbo?
Bad EBP sensor?

Thanks.

 

[Dave]

Which ECM strategy is on the truck?

 

[DZL JIM]

How do I find that out?

 

[Dave]

IDS should be able to pull it

 

[DZL JIM]

Looks like VXCF9. That sound right?

Also, just checked 3 6.0 trucks here.
'05 idles at 70% VGTDC and has slight hiss, goes away when you unplug wires at turbo. My daily driver, nothing wrong with that truck, I know it runs great.

'06 F-550 idles at 40% VGTDC, no hiss. Unplug wire at turbo and no change in sound. One of my other trucks, also runs great.

Trouble truck is '07 and idles at 85% VGTDC and has loud hiss that goes away when you unhook wires at turbo. Upon start up, the VGTDC climbs and as it climbs and changes values the hiss also changes intensity.
??

Something in the programming? Or sensor throwing values off causing VGT to activate at idle?

 

[Gearhead]

What is EBP value Key On Engine Off? if not 14-15 psi then the sensor is kaput...

Also blow air down ebp tube to make sure it isn't clogged and also that there aren't any holes in said tube.

 

[DZL JIM]

It's reading 13 psi, KOEO. Running it's 16.
Wouldn't it set a code or fail IDS test if the EBP sensor was bad?

We'll look at the EBP sensor tomorrow morning and see what the other trucks read.
Thanks.

 

[FaSSt9602]

Am I missing something? Isn't that the way the VGT turbo is suppose to respond? When I have the wires unplugged, my truck doesn't have that patented 6.0 swoosh. Plug is back in, it is right back...

Can't say much about duty cycles because it has been a long time since I have logged mine to see where they were, but 85% does seem a little high at idle. But the VGT doesn't "shut off", ever. Sounds like the two pick-ups are actually functioning normal and maybe the 550 is a bit off. You should hear a change when unplugging the wires.

 

[DZL JIM]

Thanks for the help all.
Here's the deal.
We ripped it all back apart and found one of the bellows on the Y pipe split puking exhaust out.
So when we cleaned the turbo (I'm guessing that made it worse) it was able to actuate the VGT. The system is run, at least in part, by the exhaust back pressure. And with the split in the bellow it was trying to compensate for the leak, or maybe wasn't able to reach it's desired parameters or something.
So it was whooshing really bad with high duty cycle.
We replaced the Y pipe and all is well.
:thumbsup: