Help !
 

Been reading through the forums n im a bit baffled,

Got 98 sti imp,
All running std apart form DV n exhaust,
Noticed that performance has been slowly dropping over last few weeks,
Sometimes when i start her up in the damp/rain she spits n spurts before finnally settling down,Tick over when warm is only around 500 rpm and sounds eratic.
When flooring it my boost gauge is only hitting 0.7 bar and also when u floor it it seems to take a second to respond and feels as if the motors chokey.What boost should it be running ?


Recently tried to fit a hks filter and this made the problem 10x worse so went back to stock. Reading through here it seems i may have a MAF sensor issue?

If i Disconect the Battery for a while will this reset my ecu as i here they learn to adapt to a deteriorating MAF sensor?. Done a code check and no errors

Any sugestions/help Please :sos:

Dodgy Mafs dont always throw up a code error

True...

Also if you disconnect the ECU and you have a dodgey MAF it can make it worse.
The ECU will of learn't over a long period to work with the slowley failing MAF.

Resetting the ECU will bring the ECU back to stock settings and it will run v.bad if at all.
This does though point squarly at the MAF dieing.

So i guess i have to bite the bullet and disconect it, at least ill know wht the problem is?
Also if i disconect the battery to reset ecu do i have to do ne procedure to let it relearn or nething?

also wht pressure should i be running at as im guessin 0.7 bar is too low?

Will fitting new MAF (if it is this pproblem) rectify the boost issue or is that a diffferent kettle of fish all together?

Standard Boost is 1.1bar, so sounds like you are either in limp mode, the boost control pipes are connected wrong or the boost control solenoid is not working.

When you perform an ECU reset you can only achieve about 0.7bar due to the reset process closing the boostcontrolsolenoid.

You can either disconnect the battery or connect the green connectors under the steering column.

Perform ECU Reset

An ECU reset will restore the car to factory default settings. This does not effect or erase any remapped chip or adaptor that may be fitted, but it does erase any learned data that the ECU has stored in RAM i.e minor tolerance adjustments for ignition and fuel control. It will also remove any stored fault codes and restore ignition advance. It is possible to reset the ECU by following these steps :
Turn ignition OFF
Connect Read Memory (Black) Connectors & Test Mode (Green Connectors)
Turn ignition ON (engine off)
Engine Check lamp turns on
Depress accelerator pedal completely
Then return it to the half-throttle position and hold it there for two seconds
Release pedal completely
Start engine
Code is indicated by Pulsing Lamp
If a fault is detected - Check ECU code (see above)
If no fault is detected - drive the car sensible for a couple of minutes
When the ECU has been reset the Check Engine Light will flash
Code is indicated by Pulsing Lamp
If this is a On/Off pulse of equal duration, this is the 'ALL CLEAR' and no fault was found.
If this is for example 3 slow flashes and 2 fast flashes (repeated), this is Error Code 32.
If a fault is detected - Check ECU code
Turn ignition OFF & Disconnect Connectors

i done a ecu reset a week or so ago when i had the hks air filter issue,
this is prob why im running at 0.7 bar but wht porocess do i follow to get it back to stnd 1.1?
is my boost solonoid screwed?

If your connectors are now disconnected i.e you are not in diag/reset mode then you should be running 1.1bar if all else is fine.

have you replaced or have any of the boost control pipes been changed.
the pipe from the turbo nipple to a small white t-piece should have a 1mm brass restrictor inside.
if it doesn't your actuator will be opening too early, hence lower boost.

The pipes should be connected as below :
1. Turbo nipple to T-piece right hand 'T'
2. T-Piece left hand 'T' to actuator
3. T-Piece bottom connection to blue boost control solenoid
4. Boost control solenoid to inlet manifold nipple next to header tank.

While you are checking them give them all a good spray with brake/carb cleaner including inside the solenoid.

havent touched it since i got it and was boosting ok then,
Will have a good look tomorow and give it a spray up,
Would this boost issue cause the idle problems ive been having?

Cheers for the fast reply aswell :)

no idle and running issues does pointto MAF IMHO.

I treat MY99/00 MAF's as consumable items, almost worth having a spare on the shelf.
I do have a spare old unit that just started toplay up before I switched it to a new one.
Your welcome to try that to see if it improves things.

New are £70-£80 from Subaru.

ok m8, you about tomorow?
PM me ur number if thats ok cheers

I am about as waiting for a delivery, you have PM

just a post to say thanks to silversurfer,
Turned up at his place, he lent me spare MAF n boost control soloniod,
Got home installed and did a reset and it all runs perfect,
Just off to subaru now to buy a new MAF @ £98,typical just before xmas but the kids will just have to go short this year lol
Thanks again n will pop bits over shortly:doubleup:

No worries Nick, glad to be of service and glad it seems to of fixed it
No rush getting bits back, have a good christmas if I don't see you before.

Funny mine failed this time last year but culverwells had one in stock.

very nice looking car Nick

Silversurfer to the rescue again tonight. Had a secondary issue and remains to be seen might even be a primary issue with my car, and courtesy of Scott, diagnosed as dead maf on my car. :( Call to Culverwells tomorrow to see if they have one on the shelf.

I can see why people go mafless, they seem to be a real weak point. Even my wifes Zafira one failed which is an almost identical maf. Crap design if you ask me.!

So identicle it's worth loggin it's performance against a Suaru one, you can bet the Vauxhall one would be cheaper.

Can you ping me the Bosch Pt.no that are on both your old Subaru one and the Vauxhall one.
The Bosch number is the one under the Bosch logo.

Top man Scott. :10: