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?

 

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

 

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.

 

why isn't it hitting fuel cut?

 

I would just be happy with my wife wanting to drive a car at WOT =]
oh and port your wastegate.

 

Open exhaust and intake + stock wastegate = boost creep.

Port the wastegate or restrict the intake/exhaust.

 

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.

 

Fuel cut is at 8.6psi, but the turbo can easily overboost before the fuel cut happens. Boost will obviously decline as soon as the fuel is cut however.

 

id make sure the waste gate acutator is opening properly

 

we've had an apex'i cat-back and bonez catalytic converter on it since the day we bought it and it never had any issues until after this. boost creep isn't an issue that just randomly pops up. next time i have the turbo off, i will port it, but i don't think that's the primary issue

i know the hoses are in the right place. it's possible one might be crack and i just can't see it. i'll have to pull them back off and double check. as for the boost gauge, i had a highly modified FD and i know even stock, there's going to be issues with rx7s. the stock boost gauge sucks *** and i wanted to keep an eye on things. i'm **** about watching gauges and making sure nothing is going wrong

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

 

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.