Running on full boost!!! AAAHH!!!

**USMarine430** · 10-14-2012

Ok folks. . . have a real dillema. . . When I start the car the boost bypass immediately goes into full boost - its not flopping around like it should be

. I just replaced the solenoid within the past few months, and to test it I checked the ground for continuity and it clicked - and I replaced the perfectly good new one with the good used one. Same thing. It keeps going into full boost and it is stalling out my wifes car and she now hates the world and the car

.

All of the vacuum lines are plugged in, and I cant see where there would be an issue unless its internal. . . HELP!!!

(2001 3.8L GTP Topswap)

**Sushamouf** · 10-14-2012

Have you tried replacing the valve itself? Maybe the diaphragm is torn. Does it move at all when you start the car or rev the engine?

Sent from my Droid

**USMarine430** · 10-14-2012

dear heavens thanks for responding. Yes the valve goes from completely relaxed (all the way down), and immediately flops all the way to full boost when it starts and will not bob up and down like its supposed to.

I am freaking out maaaan. . . .super troopers style

**TEK310** · 10-14-2012

replace that and your car will work again

**Sushamouf** · 10-14-2012

Flopped up is open, flopped down is closed. It should flop up when ypu start the car and flop down when you rev it good. It operates of vacuum.

Sent from my Droid

**USMarine430** · 10-14-2012

i thought it was boost on demand.. . its supposed to flop up, which it does. . . but this flops all the way up on full boost. ever since I have had the car it would bob up and down and as you accelerate it goes to full boost. this immediately goes to full boost and subsequently stalls out at start up.

**Sushamouf** · 10-14-2012

If its moving, its working. Up is bypassing boost down it is not bypassing.

Sent from my Droid

**USMarine430** · 10-14-2012

so it is supposed to be full boost all the time?
Its supposed to go from its resting position to full boost with no fluctuation afterward? That is what its doing - its on full bypass

**TEK310** · 10-14-2012

if it is not down(sitting on the SC stop block) then you are not full boost, it is open

**USMarine430** · 10-14-2012

so replace the boost bypass valve? and things should be good to go?

**TEK310** · 10-14-2012

if the valve is staying closed yes.

**Sushamouf** · 10-14-2012

This is how it should work.

http://www.youtube.com/watch?nomobile=1&v=EA7J_qIurAU

Sent from my Droid

**USMarine430** · 10-14-2012

yeah its not cool like the video. . . . it just goes to full vacuum right off the bat and stalls out

**dsmuts** · 10-14-2012

does it run if you hold it where it should be?

**Sushamouf** · 10-14-2012

I doubt the bypass valve is causing ypur problem. It should run fine even if you are always running full boost.

Sent from my Droid

**USMarine430** · 10-14-2012

Originally Posted by dsmuts

does it run if you hold it where it should be?

No sir, it does not. It starts, the bypass immediately goes to full boost, and then it stalls out.
I removed the bypass and I don't see anything wrong on the exterior - the diaphragm looks fine . . .

**matt5112** · 10-14-2012

How are you making boost at idle even with the BBV closed?

Also whats a GTP top swap mean?

**TEK310** · 10-14-2012

did you hold the valve open? which would be holding the lever up

**USMarine430** · 10-14-2012

Originally Posted by matt5112

How are you making boost at idle even with the BBV closed?

Also whats a GTP top swap mean?

The block is a stock 3.8 naturally aspirated. the top (heads, intake,) were removed and a supercharger, underdrive pulley, GTP heads and injectors were added. a 2007 transmission and ECM were added too.

SO, yeah to answer your question - I dont know - that was essentially my question and why I am here trying to figure out situation because I dont know.

**matt5112** · 10-14-2012

a 2007 ECM is untunable and wouldn't work with your combination.

It wouldn't know what to do with your injectors, have the wrong cal for your MAF, would want to see a TAC instead of an IAC/TPS.

It'd either command too much timing and run too lean OR transmission wouldnt know when to shift.

So, are you sure?