Headgasket job underway

Dzchey21 · Feb 1, 2012

madman1234509 said:
maybe, ill switch to thottle position sensor on the dd and watch it in the morning, could be a bad tps, but then again id kind of expect it to do it all the time not just with the tq converter locked. As of right now im going to leave the gate how it is (shut/non opening) If its not opening it cant contribute to the problem.

The doubt its the TPS is bad since its a dual axis sensor, but i've seen stranger ****.

madman1234509 · Feb 1, 2012

I'll check it out when i drive it on the morning. Am I remembering correctly that I saw two throttle positionvalues that I can watch on the dd? Is that what you mean by dual axis?

CamTom12 · Feb 1, 2012

You want to watch value "D"

MINK · Feb 1, 2012

I'm still watching to see what you find - You have me thinking my own problem could be in the vgt control as I swapped another set of turbos on before my surging started/during my build. Damn black 6.4 curse...

Jhaddox · Feb 1, 2012

Those Turbos never gave me any problems when they came off and are practically new:shrug:

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MINK · Feb 1, 2012

Jhaddox said:
Those Turbos never gave me any problems when they came off and are practically new:shrug:

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This I know....Just baffled as to what my issue is brotha

Jhaddox · Feb 1, 2012

Ask Eric larch..his truck was giving him an awkward issue and it was a sensor plugged with soot, he might be able to point you in a direction

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madman1234509 · Feb 1, 2012

Accelerator pedal position "e" and "d" are both consistent and constant, no fluctuation. What else....??? I'm stumped, besides the vgt being bad. But why does it only do it under load with the tq converter locked and no other time

Dzchey21 · Feb 1, 2012

Doesn't make sense at all.

I would blame the actuator before anything. I have a spare I would be willing to send you to try if you pay for shipping and promise to send it back lol.

I know I asked but does vgt duty cycle vary at all when it's surging?

MINK · Feb 1, 2012

Are the actuators that bad to swap they dont appear to be? I have an extra so Ill swap it this weekend and see what happens with my surge.

UpstateDieselGuy · Feb 1, 2012

His VGT Duty Cycle goes up and down sharply when it happens. I was watching the Data Log while it was happening. I wonder if it is the EBP Sensor acting up?

madman1234509 · Feb 1, 2012

If you watch my vids a couple pages back, the vgt duty cycle moves a lot. The graph looks like saw teeth. It's the only thing that fluctuates like it shouldn't

madman1234509 · Feb 1, 2012

Well talked to my mechanic today. I did graph and log my Desired EP and Actual EP one more time. My actual EP did jump around. Now I just need to find out if its the vgt fluctuating thats causing the exhaust pressure to fluctuate, or if the exhaust pressure dropping off if causing the vgt to tighten up and fluctuate. One way to do this. Take the waste gate off, cap it off and drive it. If it still fluctuates then it has to be the vgt causing it. We did test the waste gate yesterday and it seemed fine, and my friends gate is the same exact thing plumbed the same exact way so who knows. I work till friday then I will be out of town all weekend so hopefully early next week Ill be able to get the gate off and try it.

** BTW if it is my vgt turbo acting up.... Custom compunds will be put on ASAP... 64mm and 82 or 83mm on stock fuel for the time being...
And I have no fuel line vibration or noises with the ported rails, although for some reason my fuel rail pressure does spike over 28k psi when I get on the gas, never did that before.

Dzchey21 · Feb 3, 2012

madman1234509 said:
Well talked to my mechanic today. I did graph and log my Desired EP and Actual EP one more time. My actual EP did jump around. Now I just need to find out if its the vgt fluctuating thats causing the exhaust pressure to fluctuate, or if the exhaust pressure dropping off if causing the vgt to tighten up and fluctuate. One way to do this. Take the waste gate off, cap it off and drive it. If it still fluctuates then it has to be the vgt causing it. We did test the waste gate yesterday and it seemed fine, and my friends gate is the same exact thing plumbed the same exact way so who knows. I work till friday then I will be out of town all weekend so hopefully early next week Ill be able to get the gate off and try it.

** BTW if it is my vgt turbo acting up.... Custom compunds will be put on ASAP... 64mm and 82 or 83mm on stock fuel for the time being...
And I have no fuel line vibration or noises with the ported rails, although for some reason my fuel rail pressure does spike over 28k psi when I get on the gas, never did that before.

Yeah let me.know what it does with the gate capped off