Coming home on motorway last night, long run, I noticed when I put my foot down I got overboost and then fuel cut...

STill doing this today, although not until the engine was really warmed up on the motorway...

any ideas?

MY01 WRX PPP, Miltek sports cat exhaust... nothing changed recently...

 

Check for split hoses along the entire route from the turbo output nipple to the boost solenoid to the wastegate actuator.

 

Cheers for the advice...

looked at the pipes and replace one that looked iffy that runs from t piece to actuator. The other one with the orifice still looks ok but I have ordered a new one of those..

however... I'm still getting high boost levels and occasional fuel cut now, although not as often. If the other hose is not the culprit what could it be? solenoid playing up?

 

any help from the evening crew?

 

What are the symptoms?

Total loss of power for a split second, like a nosedive?

 

boost builds.. to over what it normally does and then will drop back down to virtually nothing... sometimes doesn't come back until you reapply the throttle.. also occasionally when you floor it I get no boost to speak of....

it's not a total thump in the back but it's not so harsh as that..

 

This is driving me nuts. Here's a full low-down on the problem -

Boost is alittle irratic and sometimes over the top.

The car (MY01 WRX, PPP Miltex sports cat, STI Intercooler with no other mods done in the last 4 years!) used to run (using a defi sensor to SECS unit) upto about 20 psi but 19 normal. However now -

on part throttle (say 3/4) it will boost to about 16/17 then drop off to 6/7 and then go back up again and will do that continuosly.
On full throttle will boost to around 24 psi then drop and SOMETIMES not come back up again until throttled off and back on again.
Sometimes it will just go to about 7psi and stay there...

I will double check teh piping again but could it be -

actuator
Solenoid
or a leak

outside chance MAF?

it's realy odd as I don't seem to get violent fuel cut more of a gentle boost dropping rather than a sudden drop and it doesn't drop to nothing either...

 

i had the exact same problem.

i checked all the pipes by spraying nearly the whole engine with soapy water to see for bubbles. NOTHING

i spent weeks trying to find out what the problem was and then i did, my actuator was dropping pressure, it was reaching boost and allowing the wastegate to open, wich in turn gave over boost and would hit the fuel cut point.

go to a garage and ask them to check the pressure of the actuator and see if it is dropping, if it is then thats your problem.

hope this helps David

 

thanks for the advice david..

This morning I played with the actuator arm and noticed it was a bit grindy and notchy.. I have applied a liberal dose of penetrating oil and it SEEMS ok now.. time to change it I think...

Can anyone confirm that the actuator would cause this?

 

anyone?

 

bounce