3406b low boost and fuel pressure issues

Break over spring is on throttle lever itself..

I have seen the back of the turbo look fine until it was pulled out of the exhaust housing. The fins have a flat area that will get damaged first.

With the type of boost leaks your describing it should have really warmed up on the pyro. Small leaks that don’t affect pressure will warm one up, you may not notice till you fix them. A leak big enough to gain pressure when fixed it should have warmed up and trailed smoke longer between shifts.


If it’s fuel it’s the rack not moving all the way to full fuel. Any smoke? Did you get the nail head back in fork on afrc? If it happened suddenly and changing afrc didn’t change anything I don’t think it’s anything not put together right. Pull the rear cover that line runs to on AFRC. Plug the line at intake. Put a 1/4 inch drive 9/16 socket in the cover so that square drive pushes against adjustment screw. Carefully and slowly tighten bolts if it gets stiff stop even if it’s not bottomed out. Go drive it see if it’s better. That will tell you if the boost isn’t moving the afrc.

 

Thr ceramic manifold will help keep EGT's lower, but EGT's will still go up if you lose boost but not fuel.

Since your EGT's haven't risen, i would assume a fuel issue and do @wore out mentioned.

I had an issue a few months back where i lost about 10lbs of boost. Low power, about 100* higher EGT's, and black smoke.

I knew boost was my problem with the EGT's and smoke. My turbo was only a month old, and there was absolutely nothing wrong with it i could see. Everything else checked out good and i finally just replaced the turbo.

Fixed

 

No not the return spring. Without the engine running open throttle you will see the round piece stop then the lever will go a bit more then spring back as you let off.


Check the rack is hitting the stud with the test light.


The boost pressure your making is it pretty snappy or real laggy

 

Find a way to plug off the rubber elbow from fresh air side of turbo. I use a pump up sprayer that I have had for years. Put an air chuck on intake side with a regulator set to 10 psi. Hook the air to it. This checks the whole system. There should be no leaks anywhere. Including out blow by tube. If your good there check the clamp at turbo that holds cartridge in exhaust housing. Make sure it’s seated there. Make sure the compressor wheel has no damage then pull turbo and see if the gasket between the ports is blown in middle. See if manifold or turbo is eroded in the middle. If either are pull the exhaust housing and see how bad the exhaust wheel is

 

Yes on hook it to intake manifold

And yes on the filter. That is a deal on that too