So i have been having a problem with vibration. Thought it waz the front mount, but not so sure now. Cruizing down the highway I am pulling less vacuum. And when put under load only show 5# on gauge but sounds likeits boosting 20#. Working with an LSJ here. I am wondering if the converter is backed up. Factory Exhaust.

 

Other way around, plugged cat will cause higher boost levels. You most likely have a huge vacuum/boost leak, check all your vacuum lines and bypass valve

 

Ok so looking at the bypass from front of car there are 2ports on front and one on back 1 lower front port has no hose. I cannot remember is something missing.

 

Here is what im talking about
Can anyone send me a pic of what its supposed to look like.

 

come on guys no help out there

 

Looks like all lines are here.

its not the valve, it will hold a vacuum. I need to replace vacuum lines, but that's not it. the solenoid well not sure how to check it. I do however hold a vacuum on it from the short upper hose on the valve. I don't get full boost until Im at redline. What effects could the vibration have on this.

Could this be caused by a bad crank balancer, (harmonic balancer) causing vibration and the knock sensor pick them up retarding the timing etc.

I just had my fuel pump replaced due to recall. If it was a fuel related causing low boost, wouldn't I get a code of some sort.

If it was a timing related issue, I would think I would get a code also.