No turbo boost

[TurboDiverArt]

Hi all,

Finally got around to finishing up the installation of the BD X-Monitor. Everything went smoothly. Much to my surprise, I have no boost! I double checked it with a mechanical gauge and even with my foot to the floor, just vacuum at the waste gate solenoid. I didn

[whatnot]

With the engine idling, the wastgate linkage shouldn't budge at all. If you can move it and you have vacuum at the actuator then it is probably leaking.

[TurboDiverArt]

Is the actuator rod suppose to be opposite at idle and engine off? I thought that the actuator (puck) would stay shut all the time and when the PCM determined there was too much boost, it would start opening the puck and bleed off exhaust. Does our diesel engines work differently? Seems that with the engine off that the puck would be closed as well as at idle.

I can move the actuator rod when idling but you do have push down pretty hard but it

[gmctd]

The wastegate seems ok, Art.
Vacuum on the actuator closes the wg, at ~15"
At the pump should be ~25" at idle
PCM is regulating vacuum thru the wg solenoid by a vent port, which bleeds wg vacuum with engine off - wg opens.

IIRC, the GN wastegate is spring-loaded closed, using vacuum to assist exh pressure in opening it. Vacuum-assist is enabled at incidence of pre-ignition\spark knock - protects the engine.

Disconnect the new wiring for monitored boost readings, reconnect the original, see what happens.

[whatnot]

Have you checked to make sure the turbine is spinning?

[TurboDiverArt]

Originally posted by gmctd:
The wastegate seems ok, Art.
Vacuum on the actuator closes the wg, at ~15"
At the pump should be ~25" at idle
PCM is regulating vacuum thru the wg solenoid by a vent port, which bleeds wg vacuum with engine off - wg opens.

IIRC, the GN wastegate is spring-loaded closed, using vacuum to assist exh pressure in opening it. Vacuum-assist is enabled at incidence of pre-ignition\spark knock - protects the engine.

Disconnect the new wiring for monitored boost readings, reconnect the original, see what happens. You're recollection about the GN actuator is correct. Boost pressure is used to overcome spring pressure to bleed off boost.

The truck seems to run the same with the X-Monitor hooked up. When I checked using the mechanical I used a Tee between the wastegate line and wastegate. I just ran to an old fashion vacuum/boost gauge. I stalled it up in the driveway with the hood open so that the hood wouldn

[whatnot]

If you have vacuum at the turbo then I doubt it is the wastegate solenoid.
If you have a hand vacuum pump, you could put it on the actuator and see if it will hold the vacuum.
You can take the air cleaner hose off and start the engine if you are careful to stay away from the spinning parts. It should be spinning pretty good at idle.
I have read post here about the wastgate arm breaking loose from the wastegate. (the weld on the pivot shaft) You might want to also check that.

[TurboDiverArt]

Originally posted by whatnot:
If you have vacuum at the turbo then I doubt it is the wastegate solenoid.
If you have a hand vacuum pump, you could put it on the actuator and see if it will hold the vacuum.
You can take the air cleaner hose off and start the engine if you are careful to stay away from the spinning parts. It should be spinning pretty good at idle.
I have read post here about the wastgate arm breaking loose from the wastegate. (the weld on the pivot shaft) You might want to also check that. I can check that all out. I was going to pull off the intake pipe to check the wheel for any play, I can easily start it as well to see it spin.

You're talking about the wastegate rod connecting to the puck (flapper) armature in the exhaust housing?

Art.

[markelectric]

My wastegate flapper was swinging on the shaft at one point also. my mechanic welded it only for it to break again. I rewelded it with a TIG machine an have had no problem since.

[TurboDiverArt]

Originally posted by markelectric:
My wastegate flapper was swinging on the shaft at one point also. my mechanic welded it only for it to break again. I rewelded it with a TIG machine an have had no problem since. Did you weld the leaver to the shaft that goes into the exhaust housing? I assume this is what you are talking about?

Does anyone know if there is a problem reading boost at the wastegate? I assume if BD Power said to tap it there that is was OK.

Art.

[gmctd]

Boost can be gaged between the compressor outlet and the heads, anywhere in the intake system.

The wastegate is vacuum-operated, and would indicate some vacuum as related to boost, but why?

Tapped into the turbine housing would give you exhaust pressure.

Can you synopsize the instructions, here?

[patrick m.]

ART, on your GN, your boost guage probably is connected to your wastegate actuator hose, on the truck, the wastegate actuator hose is not part of the intake environment. The wastegate sys is completely seperate.
You will need to conect directly to the intake system, most folks drill and tap for a fitting in the upper intake.

[TurboDiverArt]

Originally posted by Patrick m.:
ART, on your GN, your boost guage probably is connected to your wastegate actuator hose, on the truck, the wastegate actuator hose is not part of the intake environment. The wastegate sys is completely seperate.
You will need to conect directly to the intake system, most folks drill and tap for a fitting in the upper intake. Aaah crap on toast!!!! Why the heck would a company like BD Power, who knows our trucks, suggest doing this? Is this the same setup on the D-MAX trucks? Only reason I ask is maybe BD was thinking that they are setup the same. Guess next weekend I'll be taping a fitting to the intake.

Thanks,
Art.

[TurboDiverArt]

Originally posted by gmctd:
Boost can be gaged between the compressor outlet and the heads, anywhere in the intake system.

The wastegate is vacuum-operated, and would indicate some vacuum as related to boost, but why?

Tapped into the turbine housing would give you exhaust pressure.

Can you synopsize the instructions, here? Yeah, BD Power's instructions are wrong!

Synopsis:
Vacuum always to wastegate.
Boost must be tapped into.

How'd I do?

Art.

[gmctd]

Well...it ain't Reader's Digest ;) , so I'm still puzzled.

What's that 'vacuum always to wastegate'? :confused:

[markelectric]

On one of the trucks I pulled the delivery horn and tapped it. I was lazy on the other one and pulled what I think is the intake air temp sensor, installed a tee and put both in the already tapped hole. I cannot tell any difference in either way. Might be a quick way to see what is going on.

[gmctd]

That 'tee' arrangement will gage correct boost pressure, but PCM requires the Intake Air Temperature sensor be located in the air flow for accurate fuel management.

Summertime heat and ac condenser heat are of prime consideration in the sensor location.

[TurboDiverArt]

Originally posted by gmctd:
Well...it ain't Reader's Digest ;) , so I'm still puzzled.

What's that 'vacuum always to wastegate'? :confused: Sorry, vacuum always to wastegate as opposed to on my GN where you have vacuum to the wastegate all the time until you get under boost and then there is boost to the wastegate.

OK, so I'll never write for Readers Digest... smile.gif

[patrick m.]

Art, thats ok, not many of could write for "Reader's Digest".
Although, some of the guys here could prepare, and deliver a well organized, properly researched, and informative presentation to a room full of engineers and end with great applause, and much respect. ;) I know they have mine.

[gmctd]

Mine, too, Patrick.

So, what have you found out, Art? Is it ginnin'?

[TurboDiverArt]

Originally posted by gmctd:
Mine, too, Patrick.

So, what have you found out, Art? Is it ginnin'? Sorry, forgot to post back. I now have low boost. I'm registering only 3.0 psi max. That's with truck to operating temperature and me standing on it through the gears. I just started another thread titled "low boost, what's up". I'll probably do that so look for the details and update here.

http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=1&t=006297

Art.