SeepyScoob

Cars Idling fine but started to lose performance over the last month. Started to get flat spots at 4000rpm, tried ECU re-set. Made it worse but slowly it's got back to how it was.
Put it in for 60000 mile service and they cleaned all the control solenoids and the wastegate valve. Made no difference. They now tell me I need a new "Turbo valve" presume they mean wastegate?! Quoting me approx £150 for the pleasure.

Anyway, I've read lot's of stuff on here about MAF sensors going wrong and similar results. Is this the most likely cause? Opinions welcome.
If it is the MAF. Where is it? How can I test it? Can it be cleaned? Where's the best place for a replacement.

Thanks for any help guys and gals

SCOOBY TOWERS

iTrader: (7)

What type / year is your car ?

SeepyScoob

OOOOoooppps
Sorry it's an MY99 Standard UK turbo 2000 wagon.

Cheers
CP

spikester

iTrader: (1)

What gears do you get the flat sopts in? Is it worse in the higher gears or in all gears?

SCOOBY TOWERS

iTrader: (7)

I had a similar problem to what you are describing.
Mine (MY99 Turbo) idled perfectly but had flat spots / loss of power at 4k then 5k.
I tried cleaning the solenoid which helped a bit (might have been in my head) but the problem always returned.
I borrowed a mates MAF for a day and it was like adding another Turbo
I presume I'd just got use to the preformance droping over time.
Try borrowing a MAF or ask the dealers to lend you one b4 you buy, the change in performance will be instant !
They are easy enough to fit - Its part of the large black pipe that runs from the air box (where the filter is) to the engine.
Unclip the electrical connection then undo the two trox screws (you may need to borrow the correct trox bit or buy one at any local hardware shop)then gently lever the MAF sensor out (its held in with a rubber band arrangement).
Once out cleaning it with brake cleaner spray may work but they are so delecate its probably best just to replace it.
They cost £70 inc VAT from most dealers but be aware that some dealers will try to sell you the whole air box for around £300 +.
Tell them to take a running jump and have a look in their sub part directory for part number 22794AA010.
Once you have one in your hands all will become clear as to how easy they are to change.
If you have any problems mail me and I'll try and help.
Chris

SeepyScoob

Thanks for all the advice. The problem is there in all gears but most pronounced in third and fourth (Not sure about fith as I haven't been pushing on that hard). I reckon this is only cause the revs move a little slower in thir and fourth so it's more noticeable.

I did a diagnostic last night and got error code 13. Me thinks this is camshaft position sensor but I stand to be corrected.

I think it's worth checking this out now before I try swapping the MAF as I'm not getting any errors relating to the MAF sensor.

So next obvious question is.Where is the camshaft position sensor can it be cleaned up and how much is it gonna cost for a replacement. I haven't seen any posts on this one so it dows seem unusual. Could well still be MAF related. Sadly I don't have any mates with Scoobs to swap one over. Guy over the road has an MY03 STI. But it's brand new so I don't think he'd be up for it and I wouldn't like to guess if it's compatible.

Anyone else live in the Melksham area with an MY99 turbo want me to borrow MAF\Camshaft sensors?? Hmmmmm??

Again thanks for all the good advice.

JayTee

How did you do the diagnostic test?
As I having simular problems with my 1999 Jap WRX

http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=243727

SeepyScoob

Dead easy really.

First find 2 black connectors under the steering column that are not connected. They may be tapped up with blue tape.
With the ignition off join the wires connectors together. Turn the ignition on but don't strat the engine.
The check Engine light will flash a code and you will have decifer this.
Take a look at:
www.saxonfields.freeserve.co.uk
Under Impreza ECU codes and all will become clear.

Don't forget to turn ignition off and disconnect wires before starting.

SCOOBY TOWERS

iTrader: (7)

Cam sensor made need cleaning - again a 10 min job to DIY.
You need a 10 mm spanner and adjustable wrists
Its located behind the cam belt and is a little orangy / brown thing with a wire connector sticking out of it.
Just Undo the 10 mm bolt and pull out.
Its a cylindrical block of metal.
Give it a good clean, reset the ECU , go for a run then check for error code on return.

Reset the ECU by connecting the two green connectors under the dash with the ignition off, go for a 2 min run , when the CEL starts to flash, stop, switch off and disconnect the plugs.

Chris
Edited to add - My ECU showed no fault code even though the MAF was FUBARED. It's under reading the air flow so just thinks theres less air than normal and therefore no fault.

[Edited by SCOOBY TOWERS - 8/29/2003 12:00:31 PM]

SeepyScoob

Cleaned camshaft sensor... Bugger all difference.
Bought a new one... Bugger all difference.....

Cleaned MAF sensor... Got a bit better....

Should have listened to Scooby Towers (Cheers ST)

Will be trying to get a new MAF tomorrow.

Oh well £107 lighter for a cam sensor and no better, what a bummer!!

By the way when I phoned to get a price for a MAF, they all tried to sell me the whole unit for £220 +VAT (Tried three places) after I told them NO!! I just want the sensor, check your sub parts list!!
They all backed down. £62.50 +VAT. Good job you guys gave me a heads up or this would have cost me a lot more.


Thanks for the great advice as usual, should have listened.

SCOOBY TOWERS

iTrader: (7)

Hope you get it sorted.
Post your results .
Chris.

SeepyScoob

Well picked up the new MAF sensor today, bit overpriced at £90 but it was that or wait until Friday. And I was getting soooooo hacked off with the car.

Fitted it within 10 mins. A nice gentle ECU reset for good measure.

And......... and....... F*ck me!!!!!!!!!!!

I've got a new Impreza!!!!!

Top stuff mates. Chris (aka Scooby Towers) I owe you one I really do.

After following the CEL codes and wasting 100 squid on a cam sensor (I'd like to think it was on the way out) I wasn't convinced it was the MAF especially when the garage kept banging on about the dump valve.

I am over the moon. And my missus thanks you too as I've been a miserable basket, so she says??!

Smiley face; smiley face; smiley face; smiley face; smiley face; smiley face (Sorry I've never been arsed to find out how to do them)

SCOOBY TOWERS

iTrader: (7)

Glad you got it sorted - as I said - its like adding another Turbo
Sounds as if you got ripped, but £20 over isn't to bad !
Stick you cam sensor on the for sale section and try and recoup some of the £100.

Chris
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