Issues with kenne bell bypass valve

[Rosco62]

Did a bunch of research couldn't find a whole lot of info. I found that the plug that the bypass valve vacume hose was just not connected correctly to the bypass valve and I believe that is what is causing my fuel trim difference bank to band causing misfire,sputtering, loss of power, ex. After looking on kenne bells web sight they say that if you have aggressive cams you would have to upgrade to a low pass bypass valve. Anyone else have any issues with this in trying to decide if I should just buy the replacement fitting or replace the whole valve any input would be appreciated i need to order parts today so I can get the car in the shop next week!

Mods going to be in place for next tuning session next week if issue is resolved

2007 gt
Mmr 1000 4.75
Comp came stage 2 blower cams
Ported heads
Kb 2.6 lc stage 2
2.75 8 rib pulley
Bbk 62mm throttle body
Gt500 pumps and kb 40 amp boostapump
90mm maf and mafia
Bbk shorty headers
Flow master 3in exhaust
4in cai
Ext.

 

[Timmbo]

First thing you need to do is get a gauge and measure your current vacuum. I would do that asap, because if your running below 10" of vacuum your going to destroy that head unit. I'm running 16" of vacuum with Hot Rod cams on my 2.8L Mammoth and have no issues with the stock bypass valve. If your running lower than 10" of vacuum your going to need KB's custom vacuum canister. But I'd say if your running 10" or below with those cams than you've got a problem somewhere else.

 

[lito]

The bank to bank difference is normal on KB because of their bypass design.

 

[Rosco62]

Even at 10%?

 

[blownGTvert]

The KB low vac bypass valve has a red colored cap. Most all of thier kits ship with this bypass now.

 

[Rosco62]

I'll have to check that then

 

[lito]

Even more than that, is because how the bypass while open source its air and changes the distribution in the manifold, at higher loads than idle, even with it still open the split tends to disappear.

 

[Rosco62]

Would this still happen at idle?

 

[blownGTvert]

Would this still happen at idle?

How much vacuum do you have at idle?

 

[lito]

Would this still happen at idle?

At idle it would be the worst, with flow it will even out as you start using more air.

 

[Department Of Boost]

I have a KB low vacuum bypass valve new in the box I never used during my KB days. If you want it LMK. I could ship it out today.

 

[Rosco62]

Idle is at 4 inhg but right now my vacume line isn't hooked up well I'm missing th nipple to its being shipped from kenne bell now. They seem to think that I already have the lowpass I'll have to look if I don't have it I will deffently pick up the one you have Department of Boost

 

[eighty6gt]

4 in good grief

Car has all sorts of interesting things going on... MMR engine, MAFIA, BAP.

 

[Department Of Boost]

4 in good grief

That's what she said <insert rim shot here>.

 

[Rosco62]

Interesting ? I don't know if I should be offended lol

 

[eighty6gt]

BBK throttle body!

You have a lot of parts I've seen give people grief in the past. I hope everything works out.

 

[Department Of Boost]

Interesting ? I don't know if I should be offended lol

You shouldn't be, it was just your standard 5th grade dick joke.

 

[Rosco62]

Well some 15 year old kid pulled out in front of me so I swerved and hit a light pole...

 

[Department Of Boost]

Well some 15 year old kid pulled out in front of me so I swerved and hit a light pole...

Seriously? Damn man, that sucks.

 

[Rosco62]

Ya pretty much car was supposed to go into the shop tomorrow...