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Discussion Starter #1
Hey guys- I recently got on here as I needed help with some PMD / injection pump issues...

After that hump I’m experiencing some issues that I’m wondering if you all could help with. Basically no boost; no power up hills.
This is a 2000 Chevy 6.5// short school bus- so it pulls a lot of weight but has never been this sluggish.
Drove it 300 miles south the other day and by the end of the trip it was acting erratically. We came down a big pass and she got going 70mph plus after starving for air the whole time and started erratically revving and dropping power.. seemed like a wastegate issue/ turbo...

Codes:
P1656
P0236
P0251
P0606

Not sure if this turbo is toast; it still has some power so I suspect not. There is some oil residue coming from intake and other top turbo port

My questions are;
How do I determine if the Wastegate Solenoid is bad? I’ve gone through someone’s boost check list here..
I’m getting vacuum from the vac pump. Vacuum up to the WGS.. with vacuum to actuator the actuator is pulled closed. No ability to open by hand at that point with engine running. No voltage to WGS.. Also curious about the Turbo Boost sensor.. I don’t want to throw money into new sensors.. just concerned the WGS has no power to it & all these codes with no power..

Any help is appreciated! 🙏
 

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Verify vacuum from the pump with a gauge. You should see no less than 22hg. from the pump.
Inspect every inch of vacuum line. If you still have the OEM plastic vac line I recommend that you change it for rubber line.
Those lines become brittle junk with age/heat exposure.
Re-verify you have 12v power going to wastegate solenoid. If not, check your fuses. then go through all grounds.
If you still experience issues then replace the wastegate solenoid with an AC/Delco brand.
Replace your CDR.That will eliminate the oil residue on the Turbo.
 
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The WGS solenoid should have 12v. on the pink wire with the key on.
It is on the ECM-I fuse.
The PCM controls boost by PWM the ground (YEL wire) to the solenoid.
You will see it function only while diving down the road.
Do you use a fuel additive for lubricity?
 
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Discussion Starter #4
The WGS solenoid should have 12v. on the pink wire with the key on.
It is on the ECM-I fuse.
The PCM controls boost by PWM the ground (YEL wire) to the solenoid.
You will see it function only while diving down the road.
Do you use a fuel additive for lubricity?
WGS has no power. Will check fuses.
I do not use any fuel additive. I’m a newb with diesels and maintenance in general. What’s best? / necessary? How often?
What do you mean by PWM?
Thank you
 

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PWM - pulse width modulated
The ground signal is pulsed at a variable frequency rather than trying to create a variable voltage.
Computers are able to deal with PWM much easier that a variable voltage.
 
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Discussion Starter #8
Got my check engine light to go away. Seems like it was a fuse / wiring issue.

Do you guys have any advice on why my temp gauge isn’t working?
 

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Got my check engine light to go away. Seems like it was a fuse / wiring issue.

Do you guys have any advice on why my temp gauge isn’t working?
Coolant sensor for the gauge is located on the driver's side head, close to the power steering pump
 
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