s5 tII overboosting
#1
Rotary Freak
Thread Starter
Join Date: Oct 2002
Location: Salem, IN
Posts: 1,625
Likes: 0
Received 0 Likes
on
0 Posts
s5 tII overboosting
my wife's car has been overboosting for a while now. it only does it under a load, like 3rd or 4th gear. it's hit as high as 16psi a few times. it of course hits fuel cut and the check engine light flashes. it didn't start doing it until after i had taken the car apart to replace the lower intake manifold o-ring. all of the vacuum lines are hooked up as they should be. of course, i've told her to take it easy and not let it hit over 10psi, but she can't stand driving a car that she can't hit WOT.
any reasons why it might be doing this? i'd think the solenoid would bleed the excess pressure off. could the actuator be bad? if so, how do i check it?
any reasons why it might be doing this? i'd think the solenoid would bleed the excess pressure off. could the actuator be bad? if so, how do i check it?
#2
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,826
Received 2,594 Likes
on
1,842 Posts
i would check to make sure the hoses are going where they are supposed to, the diagram isnt very clear and the hoses have to be in the right spot.
also inspect the wasetgate hoses for cracks
also inspect the wasetgate hoses for cracks
#3
Rotary Freak
iTrader: (7)
Have you modified the intake and exhaust system lately, other than your work with the mainfold? Also, the ambient air temp has been pretty cold so that may account for some of the over boost. In any case, you might want to consider pulling the turbocharger and porting the wastegate and installing a fuel cut controller.
#7
Rotary Enthusiast
iTrader: (1)
Join Date: Aug 2005
Location: Canada
Posts: 1,315
Likes: 0
Received 0 Likes
on
0 Posts
If you messed with the vaccuums, the ones for the wastegate must not be in the right place, unplugged or cracked. Otherwise someon installed a boost controller without you knowing.
And BTW, you should never ever hit 16PSI, the fuel cut is supposed to stop it at 6.5PSI. Why do you have a boost gauge if you are stock?
Spec.
And BTW, you should never ever hit 16PSI, the fuel cut is supposed to stop it at 6.5PSI. Why do you have a boost gauge if you are stock?
Spec.
Trending Topics
#8
Top Down, Boost Up
iTrader: (7)
If you messed with the vaccuums, the ones for the wastegate must not be in the right place, unplugged or cracked. Otherwise someon installed a boost controller without you knowing.
And BTW, you should never ever hit 16PSI, the fuel cut is supposed to stop it at 6.5PSI. Why do you have a boost gauge if you are stock?
Spec.
And BTW, you should never ever hit 16PSI, the fuel cut is supposed to stop it at 6.5PSI. Why do you have a boost gauge if you are stock?
Spec.
#10
Rotary Freak
Thread Starter
Join Date: Oct 2002
Location: Salem, IN
Posts: 1,625
Likes: 0
Received 0 Likes
on
0 Posts
Have you modified the intake and exhaust system lately, other than your work with the mainfold? Also, the ambient air temp has been pretty cold so that may account for some of the over boost. In any case, you might want to consider pulling the turbocharger and porting the wastegate and installing a fuel cut controller.
If you messed with the vaccuums, the ones for the wastegate must not be in the right place, unplugged or cracked. Otherwise someon installed a boost controller without you knowing.
And BTW, you should never ever hit 16PSI, the fuel cut is supposed to stop it at 6.5PSI. Why do you have a boost gauge if you are stock?
Spec.
And BTW, you should never ever hit 16PSI, the fuel cut is supposed to stop it at 6.5PSI. Why do you have a boost gauge if you are stock?
Spec.
that's the biggest thing i need to check. with the issues it has, it seems the most logical. i just wanted to check on here to see if anyone else has had a similar problem and could point me to a solution without me needing to check 100 things.
thanks guys
#11
7th Heaven
iTrader: (9)
if the boost controller on the s5 is just dumping vaccum/pressure signal, it coudl cause a leak where the wastegate actutator isnt gettng any signal to operate as intended.
A quick easy way to fix/try it is run the vaccum line from the compressor housing directly into the wastegate. It would default the boost back to 5.5psi and see if you have any problems holding it there.... then hunt down the vac diagram for the stock boost controller.
A quick easy way to fix/try it is run the vaccum line from the compressor housing directly into the wastegate. It would default the boost back to 5.5psi and see if you have any problems holding it there.... then hunt down the vac diagram for the stock boost controller.
Thread
Thread Starter
Forum
Replies
Last Post
Turblown
Vendor Classifieds
12
10-17-20 03:25 PM