Can't lower the boost!

[DR. EVIL]

I have the adjustable wastegate and a manual boost controller on the car.

the adjustable one is pretty old, the manual boost controller is new.

Is this a problem with the wastegate? is it leaking from the diaphram maybe? I can turn the manual controller either way multiple turns and still hit 24psi with a press of the foot.

I turned the wastegate 6 full turns looser and still same boost level. It seemed like it was going to stay lower then it creeped back up and stayed there again.

 

[azgn]

you need to test the wastegate........about the only way to do this is with a minivac or similar.......plug it into the vac line, pump it up and see where the wastegate opens (or not)

if it is leaking, your boost will spike

 

[DR. EVIL]

the boost is going up to 24psi and staying there until I let off (which is very quickly lol)
I've had boost spiking before and it usually goes back down very fast.

I recently replaced the eyelet end of the adjustable wastegate, when I first put it on it was way too loose and I got like 2psi, then we tightened it up and it started hitting 24psi and we have backed it off about 6 full turns and it stays the same. I can tighten the manual controller several turns or loosen it several turns with no change

The car is haulin balls, I just can't go completely WOT because I need to keep the boost at 19 or 20psi

 

[V6UnderPressure]

I had the same problem, turned out I had the manual boost controller hoses on backwards. This of course is assuming you have one going in and one going out.

Scott

 

[DR. EVIL]

I was having this problem, then I switched the hoses and still the same.....

who knows, maybe I should just loosen the manual as loose as I can go without the thing coming out and see if theres any change with the hoses on both ways.

 

[d0n_3d]

i know with my car...that i cannot adjust the boost lower even if i wanted to...i run the stock style adjustable wastegate with the stock style wastegate solenoid and no boost controller...my car won't do anything lower than 20 psi and that is with the rod not even tugging on the puck arm...

i run a 3" downpipe with dump pipe, and free flowing hooker exhaust, also running a big mouth cold air system, te-44 turbo and stock intercooler...

that's why i had to get alcohol injection, there's no way i could run lower than 20 psi on pump gas...now i run 23 psi with no knock

 

[DR. EVIL]

I'll have my hands on a ProPain system here in a week or so, so I'll need to up the boost to 24-25psi then.... so maybe I'll just hold out.

My arm has to be pulled on some to get it to loop onto the arm of the downpipe, maybe I should just keep loosening it??

 

[DR. EVIL]

I loosened the wastegate, but the boost peak stayed the same, but the spool suffered because it was too loose.

It might just be a issue with the manual boost controller.... anyone know exactly which vacuum line runs to which part of it?

Its a "T" shaped ball/spring type manual controller

the compresser should run to the end straight out from the knob to adjust it, or the bottom of the "T" of the controller?

 

[DR. EVIL]

update:

I loosened up the manual boost controller a few turns and the boost stayed at the same level, however the spool got slower. I tightened it back up two turns and the spool returned to normal. Does this mean I have the controller's vacuum lines backwards?

 

[V6UnderPressure]

Just switch them and see. Its not going to hurt anything. It will at least knock off another suspect. Try it, you will notice a definite difference if thats the problem.

 

[DR. EVIL]

I switched it and it doesn't seem to spool quite as fast, but the boost doesn't instantly go to 25psi like before. It stays around 20 or so but creeps up to 22 or 23 eventually. it'll kinda sound like its breaking up when its over 20, must be knock

 

[V6UnderPressure]

Ok, so after you switched it, did you play with the valve and get any change? Obviously your better now than you were before. much safer to be at 20 then 24, if yours is a bleeder type then open it all the way up (to allow least boost possible) and see what that does. If its still going to 20psi+ then there is a problem elsewhere.

 

[DR. EVIL]

its a ball/spring type controller, not a bleeder valve.

seems like the only thing that happens when I loosen the manual controller is the boost comes on slower.

another strange thing, when I turn on the car and floor it for the first time, it acts like its breaking up some over 15psi but the second time and every time after that, its fine. Almost sounds like not all cylinders are firing for a minute.