Rpm dropping coming to a stop,clutch in
 

https://cimg5.ibsrv.net/gimg/www.sco...c45a5de3de.png

Hi,been trying to pin down a problem with my idle dropping when coming to a stop.<br/>It doesnt do it all the time.<br/>Ive cleaned iacv,cleaned throttle body plate/disc.<br/>Tightened up and cleaned connections also gently cleaned the maf.<br/>I thought it had cured it as after all this as i went for a drive and i couldnt get it to do it.<br/>Only next day it did it within a few minutes again.<br/>Is there anything else i can try before taking it back to mechanic.<br/>Cheers in advance.

Dropping to what?
from that screen grab 750rmp is the standard idle speed as far as I'm aware

Sorry, it drops to about 100 when I change down a gear and just hold the clutch.
I haven't managed to get a screen shot when it does it as it doesn't do it every time.
I'm taking it on a track day next month and want to know it's nothing to bad.
I did do logging on the obd reader but it didn't work.

Mine was doing this...faffed about and got nowhere until I swapped out the maf for a new genuine Subaru one - different car now, 100% better.

Ouch.200 quid.
Was hoping it wasn't this.
Hmm.
Can I try someone else's if I find someone with a working one?

have you tested for air leaks? Sometimes tightening all the pipes still won't help if there is a leak somewhere - is there a garage nearby with a smoke testing machine and maybe a proper diagnostic tool that could check it over? If there's no leaks anywhere then MAF sensor would be next on the list of things to check.

No problems in putting someone elses in for a test, so long as they are happy to let you use it!

I hope not too mate, but I got mine last month for about £90 from Advanced Automotive in Bristol.

Have you a cheap dump valve?

No,standard.
I did also replace the dv gasket to see if it was leaking there.
I think I'm going to try and get a known used maf and go from there.

Is yours a classic?
Couldn't see new age ones on there site?

I haven't tested as such.
Just looked over all the connections quite a few times.
I did read one of your posts about spraying eazi start though.

ezi start is handy but won't always get sucked in, pressure/smoke testing should quickly detect if there are holes somewhere and most decent garages would have the kit to do it

Mine started doing this just before my front lambda packed it it

Oh ok.i had to change front lambda on a previous wrx but the engine light came on.

Sorry yes mine is a 98/99 but I'm sure they could do something for you.

Hmm,head scratching time.
I got a genuine maf from a breaker,put it on and drove the car.
It didn't do what it had been doing.
After a while I thought let me reset the ecu to make sure it has the chance to start over.
I unplugged maf to generate fault code.
Engine died but it also started with out maf plugged in.
Once I'd plugged maf back in and restarted car I could tell it felt different and then when I drove it it felt hesitant and holding back through the Rev range.
It wasn't right but the revs didn't drop either.
So I pulled over and plugged my original maf in and it wasn't hesitant or holding back.
It also wasn't dropping idle either.
I drove around for ages and couldn't get it to do it.
I've paid for torque pro so I've done some logging of me driving around.
I'll post them up if I can work it out.

I've been out in it today and it's gone back to its old self. Boo hoo.
It's annoying because it drives and boosts perfectly.

idle control valve?

I think I've just cured it.
I knew that the k and n panel filter in it was a poor fit and I had an old standard one in the shed.
The air box lid actually engaged with a click when I put the standard one in.
Went for a drive for 20mins and it didn't do it once.
Fcuk me sideways I've been chasing my tail for weeks over this.
I think what made it worse was all the speed bumps around where I live.
I really hope I've sorted it now.
Thanks all! For now.ha ha

What also happened as well is when I worked on the car to look for the fault is probably lean on the airbox which cured it until I went over a speed bump.
Who would of thought it eh.
Fcuking cars.

There was a thread on here recently about people not able to get K&N panel filters to fit correctly.

Yeah I know, I posted on it as I had just taken the filter out and struggled to get the lid back on.
In fact I hadn't got the lid back on properly.