Alright guys, First off I ain't new to the diesel world but I'm new to the 6.0L. When I bought the truck it had a 4" mbrp exhaust with a muffler. I straight piped it. At the same time I did the smoke switch mod(turning vgt off). I done this about a month ago. While I had the vgt plug unhooked performing this mod, I broke the plug. I put the plug back anyway.. And it's surged ever since. Yesterday I finally put a new plug and pigtail on it and got rid of the smoke switch. It's still pulsing an i can watch my boost gauge fluctuate about 3-4psi. Before i removed switch you could turn the vgt of and it would stop pulsing. It only does it at slow throttle. WOT it runs fine. Any advice?

 

I"m a little confused. Did the problem of pulsing start after the plug broke? And once you fixed the broken plug the problem did not resovle, correct? If so, have you tried to connect the plug to the truck to see if that would remedy the problem?

I recenlty did a full EGR delete, oil cooler, coolant filter kit, blue spring, FICM all last week. While I had the turbo off, I did a refresh on my turbo... It did not need it, but I am very type A and figured whiel it was out to stay on top of maintence. Youtube refreshing the 6 liter VGT turbo..that may be a part of your prolem. I think the sensor needs to be hooked up for a while to see if the turbo is surging once the PCM reads the sensor is acutally there...just a thought

 

The new plug has been installed on the truck and it is still pulsing.. I have a fuel spring kit on the way from sinister diesel and also I have a new vgt solenoid. If that don't fix it I'm gonna try the icp also. I don't know for sure that that is when the pulsing started. That is just when I noticed it. Because I straight piped it and did the smoke switch at the same time. Breaking the plug that is.

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Also when it's cold you can hear it pulsing at idle. Also when it's cold it starts weak.. Like its barely catching on all 8 cylinders. My buddy who is a 6.0 tech told me icp on that one. So I have one of them on the way as well as a blue spring from Sinister and a new VGT solenoid.

 

There is a "turbo relearn" process for when the turbo stops acting right because of a mod, not sure how to do it but its pretty easy, there have been several posts on it recently. maybe a google search will find it.

 

The new VGT solenoid fixed it guys