I have searched through the forum and have not been able to find the exact same fault that I have and don’t know what is wrong or how to fix this problem so I was hoping someone on here would be able to help.

I have a 96 WRX and everything was fine until last night. I was on my way home and put my foot down to catch the lights and was hit with a massive boost of power (felt like I had hit the nitrous button that I don't have). I came off the power and when I looked at my boost gauge at idle revs it was showing about -0.8 and falling slowly. It usually reads -0.5 off boost and +0.9 full chatt. It will still hit the +0.9 on boost but this also will not hold. It's as if it's leaking out from somewhere but have no idea where. I have a standard recDV and I am not really noticing any unusual sounds. I don’t think it has gone into limp mode, as surely this would stop it from even reaching the +0.9.


Truth is, I don’t know where to start and would greatly appreciate any help.


Gareth

 

Anyone? Someone?

echo, echo, echo.......

 

Hi.

Is it allways at -0.8bar now or is it back to -0.5 now?

I have noticed that on overrun that mine can somtimes go to about -0.8 odd,but will normally sit at about -0.5

As with all these problems,its all guesswork without actually having a look at the car.

Could be lots of things really.

It may be that your wastegate got stuck shut,allowing it to build boost higher/quicker-which could point to the actuator playing up-it may be stuck open now so it wont hold boost at higher revs.

Could also be that your boost solenoid needs cleaning out/replacing.

Best to get someone that knows their stuff to look at it if youre not sure yourself.

 

Thanks for your input.

No it's not always at -0.8 bar, its like this really. I start the car and the boost gauge goes from "0" down to -0.5 bar (normal) but then slowly falls to -0.8 bar and fluctuates between the 2. If I blip the accelerator the gauge jumps back to "0" (as normal) and a full on throttle press will knock it up to +0.9 bar (as normal).

When driving for example, foot to the floor in 5th, boost will rise to +0.9 bar and then slowly go down almost as if I was coming off the accelerator. The revs stay constant but not the boost.

I have had the car for about six months now and never had any problems and the gauge has never dropped below -0.5 bar. I can hear the boost solenoid clicking when I turn the ignition on and off so I know its working and I would of thought of that was faulty I wouldn't be able to reach my max boost at all.

The actuator theory sounds viable, how would I un-stick it and stop it from sticking again? Also is there any way of knowing if its stuck i.e. things to look for? and is there anything I shouldn't touch on it? I don't want to mess with any adjustments. I don't want to make things worse!

 

Youll have to remove the turbo heatsheild,then note the position of the actuator arm-disconnect the arm and check to see that the wastegate end moves freely-if its sticky/stiff thats where the problem lies-then check the actuator by putting a foot pump on the inlet pipe,pump it a little and see if there is any movment on the arm,and that it moves freely/returns back to its original position.

When you reconnect it all,you will now know the fully closed position of the wastegate by feeling the arm stop when you pull it-note this position as it should be closed when you connect the actuator arm back to it,if it is open at all then theres more than likely an actuator prob.

Hope this helps.

 

Thanks, I will have a look in the morning. I'm hopeing its just a split hose or something but while I have the car in bits I just wanted to know what else to look out for.
Should be fun...

 

Still no luck...

I have had the intercooler off and checked all the boost hoses I could see for splits. I cleaned the boost solenoid and the actuator doesn't appear to be stuck and is moving freely. Does anyone have any idea what could be causing my problems?

 

Yes inside the small pipes that go to the actuator,there is a small one way valve. It could be this?

 

Thats a bloody good idea, I will go and have a look. As far as I know there is only one pipe going to the actuator (it comes from the boost solenoid). Is this the correct pipe? I dont remember seeing any others.

 

Yes but it goes to a tee, u cant see the valve its inside if your pipes are not too hard u will feal the valve inside one of them.

 

Can't see a pipe with a T going to the actuator from the boost solenoid. Just one straight through pipe. Mine is a pre-face-lift WRX, would I of had this T piece on mine?

I am starting to wonder if my gauge is faulty.

Anyone know if it's unusual for one to leak pressure?

 

Have u got a valve in the pipe. u only got to have pin hole and it will f88k the boost up.

 

Couldn't find valve at all but I was looking for an obvious valve rather than a hidden within the hose type , lol. I will have a look again on my next set of days off.

I have managed to get it to hold its max boost now though. Couldn't say what I did to fix it though as I was checking, cleaning and oiling so many bits while I had everything off.

My idle boost level still seams to be low though. The gauge doesn't seam to creep down like as before anymore however. It just sits at about -0.8bar.

I am sure it used to sit at -0.5bar before all this. What would you say it should be at?