What does the vacum line that is on top of the boost actuator do. If this was pluged would it cause the boost to be off, like low. I'm trying to figure out what the person that had the truck before me was doing, it seems like the boost bypass is all screwed up or was done wrong. I'm only seeing 11 on my Autometer boost gauge with a 6er and trying to figure out why. Maybe belt slipage?Thanks.

 

I've heard that the "boost bypass' that consists of some t's and elbows is unnecessary. Simply unplugging the actuator will do the trick. That's how mine is and i read 12psi with a 4# pulley and also have autometer guages. Maybe the probem is with loose fitting of the "T" underneath the dash, where the autometer boost guage was hooked up.

 

With my stock truck...with NO mods at all, except the boost bypass done with the connectors...I was seeing up to 11lbs of boost. This was on cooler nights, with the stock guage. Dont forget, the coolest night in LA is 40 deg. So I dont see how 12 lbs for a 4lb is good. Can anyone chime in on this?

 

maybe you are bleeding some boost

https://www.f150online.com/forums/sh...hreadid=153760

https://www.f150online.com/forums/sh...hreadid=153765

 

when you say disconnect completely, you mean the solenoid right. See the vacum line on top of the boost actuator is pluged. What does this do when it's pluged. I've gone over my gauge install like 10 times, it's not leaking anywhere. Something is killing my boost...

 

disconnecting the electrical plug kills the boost bypass however it may not aleviate your problem.

DO this.

start your truck, pop the hood, find the boost actuator (use a flashlight)
Play with the throttle and rev it up a little (NOT ALOT) a few times.
watch how the boost actuator works.

when you are accelerating it (RPM's going up) the lever attached to the boost actuator should be touching the stop. If it is not, (if it comes close but doesn't touch) then that is where you are bleeding boost.

IT MUST TOUCH TO FULLY CLOSE THE BOOST BYPASS VALVE

the boost bypass is an electrical override of the vaccumm operated valve, when the R's get too high the computer dumps the boost. By disconnecting it or performing the boost bypass, you are only preventing the computer to do it electrically. IT can still happen mechanically (under vacumm)

go do that and report back with your findings....

 

Thanks l-menace, going to check right now. So I understand doing the boost bypass but why would the vacum line on top of the actuator be pluged. I looked at anoher L yesterday that had the boost bypass done but hid vacum line was installed, the pink one I belive. Did someone do my boost bypass wrong, I'm the second owner.

 

OK so I just checked, that lever does not even moove. It is sitting on the stop all the time. When I rev it up it does nothing, it is completly fluch against the stop and stays there. What does that mean? Just for kicks I also removed the harness for the solenoid to see if my boost would change. I took it out for a quick spin and nothing still at 10-10 1/2. I've seen a best of 11 when it's cooler out.