SORTED BY AWD - CEL light and hesitation under boost

[wrxmania]

Anyone any ideas?

After getting my Timing Belt, RCM Oil pump and oil/filter change done at AWD, the car was fine all the way down the road.  Left it for 5 days when in London.  Took it out tonight and within 1 mile the CHECK ENGINE light comes on, but the gauges all read OK, AFR looks fine to rich.

Tried it out when I was coming home tonight - it hesitates under boost then seems to boost harder and the light goes off but when I drive normally again after 30 secs the light comes back on.  It goes out when I start the car, but pretty much stays on all the time.

Boosting @ the 1.1 bar it is set at but then will dip etc.  Anyone got any ideas?

Is it a sensor, timing, airlock, a hose etc?  Too dark to check it just now.

Oh its' a 1994 STI, no cats []

Brian []

[wrxmania]

I should add it idles fine @ 850 RPM, sounds normal (LOUD!), is not obviosuly misfiring (audibly) or banging etc, no engine noise of any note when idleing either. 

[the squiggle]

Since the CEL has lit then a code of the fault will be stored in the ECU

Under the dash is 2 black connectors, plug them together and turn the ign on but do not start the engine.

The CEL will blink out a code

2 long flashes and 3 short flashes would be a code 23......................MAF sensor fault

Do this procedure and tell us what the code is and we can start to clear the fault for you.

Initial suspect will be the Boost Control Solenoid but the ECU will point you in the right direction

[wrxmania]

Cheers Grant - going to do that - if it is the Boost Control Solenoid, can that be cleaned and, if so, where is it and how?

Brian []

[the squiggle]

Chortle

When u were asking for anyone to help i was typing out help

Now head out and find thoise black connectors and tell us what code is stored

Yes the solenoid can be cleaned but find out what code is stored and we can take the repair procedure from there

[wrxmania]

Cheers - there is a friendly local technician coming to have a look very shortly [] 

Then we can begin the repair procedure between SIDC and us []

[wrxmania]

Code 22 - Knock Sensor - is this a bad fuel batch - add more octane booster?

Brian []

[wrxmania]

Listening to it it sounds fine, technicians ears included.  Just about to do an ECU reset and then try it on the road.  The CEL light is off just now.

Wil add more octane booster.  Booked into Andy F tomorrow anyway for a health check.

Brian []

[the squiggle]

Code 22 - Knock Sensor - is this a bad fuel batch - add more octane booster?

Brian []

Might be as it says Faulty Knock Sensor or it could have registered a massive knock reading and triggered the CEL

Andy will be able to tell when he plugs in his laptop

[wrxmania]

Hi Grant,

We have tried resetting it and taking it for a run - feels as if the ignition is certainly retarded but it won't allow us to reset it - the CEL light comes back on immediately and still flashes the code.

I have put more octane booster in it and turned the boost away down.  Do you think it is safe to drive - it does not sound unhealthy?  ALso, is it common to have a faulty knock sensor?

Brian []

[the squiggle]

I would not class it as common but i have heard of them failing.

If you drive it to Andy, drive it on light throttle and NO boost at all

Try and source a Knock Sensor from dealer or breaker before you go to see Andy.

Supplementry question?

Where did you get fuel from last and when?

 

[wrxmania]

Fuel came from Shell Whitburn, on Tuesday I think it was.

Do you think a dealer would have a sensor in stock tomorrow?

I have set the boost controller to zero so it should not boost at all.

Worried now [] []

Brian []

[the squiggle]

Boost controller set to Zero will still make wastegate pressure of 0.5bar.  Just keep the throttle light.

Unknown as to dealer availabilty of Knock sensors

[paddy247]

Just spoted this Brian, good advice handed out to you by Grant, Just pop up to AWD  and they will  reset the ECU and confirm what sensor it is ect with the subaru diagnostc moniter, Have seen a few Knock sensrs fail on the earlier cars, or as grant says maybe it has just read a massive knock, Fuel related I would pressume, Sensors are in stock at AWD give them a call to see if there is one in stock for yours.

Paddy

[wrxmania]

Cheers Paddy []

I touch goats

 

[wrxmania]

Just managed to get the ECU to reset after "changing the procedure" lol

It reset, code gone, and car driving as good as normally - HOORAY.  Reversing into the drive and lo and behold ON IT CAME AGAIN []  Checked the code and it is still a code 22 Knock Sensor.

After a spot of research on Scoobynet, it seems there has been quite a spate of them recently.  I hope it is just the sensor.  The car runs fine (when not retarding) and the AFR seems fine.

AWD tomorrow I hope followed by Mr Forrest in the afternoon.

Fingers crossed []

Brian []

[wrxmania]

And TOP OF THE LIST - a knocklink ASAP!

[micra_wrc]

And TOP OF THE LIST - a knocklink ASAP!

Brian, there was a chap selling a discrete knocklink back in August when I was looking for one.......... CLICKY

[wrxmania]

Cheers for that Imy but he has not been online since the 17th August so I guess he will not get my PM []

Will keep hunting - may end up with a new sensor tomorrow...

Brian []

[wrxmania]

Sorted - HOORAY!!

Big thanks to AWD for fitting me in at no notice, carrying stock of Subaru parts and solving the issue.

New Knock Sensor fitted, Select Monitor check and BOOST BACK ON []

Off to Andy F now for a health check, det cans and wideband []

I'll keep you informed [] []

Brian []

[wilky]

I had a faulty knock sensor on the falcon when I first bought her in 2001. It isnt very common but it does happen. Glad all is well.

Callum

[paddy247]

[][][au]

[craig mac]

Imy

You should have given Wuz a shout as am sure he has these in stock and ready to supply / fit

CraiG

Wait did he not do one for you anyway?

[wrxmania]

Hard to get for Uncle Wuz at the moment.

Yet more thanks are due to Andy Forrest today - he listened to the car on the road, with 2000 wires, cans and boxes with lights []  The car is running very well, rich at the top end, virtually no noise at all, top mount easily doing its' job and to quote the man, its' making good power for the mods on it.  No need for an Apexi set-up, which is a bonus, as I have no plans for HUGE turbo and front mount etc. 

I can now feel pretty confident that the car is running as it should be.

Thanks again to AWD for sorting me out at no notice and Andy for his time..."Praise be to God!"

Brian []

[wrxmania]

I had a faulty knock sensor on the falcon when I first bought her in 2001. It isnt very common but it does happen. Glad all is well.

Callum

Cheers Callum,

The senor had a crack down the side so was waiting to happen really. 

It's been an expensive day - sensor fitting, fuel [], Andy, Insurance, Goodridge brake lines, fluid and pads, going away for a few days so accomodation booked/paid for too [] 

I need to get a third job []