Bish

Sorry for delay in reply, weather has been a nightmare here. Well just to update, I changed my thermostat yesterday which has completely solved the problem. When I took the thermostat casing off it became clear the old one had been removed by previous owner. All that was left in was the outer ring of the thermostat (to seal I imagine). My poor idle was probably due to rich mix when cold starting as the lack of thermostat was not allowing the engine to heat up properly. Was a bit of a pain trying to get the casing off, but managed it without taking any other parts off. Replaced coolant and burped the system. All good now

have you had chance to clean the iac valve yet? i only ask as im having almost exactly the same issues with my 93 wrx but am waiting to order the gasket for the valve before i take it off.

No mate I'm also waiting on a replacement gasket before stripping. In the meantime I'm going to try changing the thermostat and replace the coolant as I've noticed the the engine is taking a while to heat up on cold start. When it finally does reach optimum working temperature (10 mins approx) it drops again when driving but not to zero (probably about quarter way up on the dial or slightly less). When I stop again and let it idle the temp goes back up to working temperature after a couple of mins. If I start the car first thing in the morning and drive away immediately (gently) the engine temp doesn't reach optimum temp until I come to a stop again! Expecting the thermostat to arrive on Monday so will see how it goes when I've replaced that.

Thanks again Col, a picture paints a thousand words as they say! I'll let you know how I get on Monday when I get a chance to work on it. Cheers

I wonder if the IACV is closing too much? The IACV contains two valves, the first is the air cut valve that is open when the coolant is cold and then closes as the coolant warms up.

The second valve, the duty cycle valve, is ECU driven and is used to set the overall preset idle speed.

If your seeing the idle revs drop way down, I wonder if the air cut valve is closing too much. As the coolant temps have now risen so much so that this valve is now almost shut and in turn reducing the ammount of idle air getting to the intake. With this major reduction in air flow, would this cause the hesitation?

As the coolant temp rises more, the thermostat then opens forcing coolant to the radiator and thus reducing the coolant temps. With the coolant lowered the air cut valve opens a bit to let the idle revs go back to normal?

When you remove the plug from the IACV the revs will move as the duty cycle valve has no signals from the ecu to control it so the idle levels will vary.

I wonder if the bimetallic strip is not reacting to the coolant temp changes and closing the air cntrol valve too much?

Just a thought.

Cheers,

Col

Wow Vimmy thank you for that wealth of technical info! Exactly what I needed as I wasn't sure exactly how the IACV worked and was due to reverse engineer it myself on Monday.

What you've described sounds very likely and would make perfect sense. I presume the bimetallic strip works on a heat principle ie similar to an old smoke alarm? If the "air cut-off valve" was struggling to close then I would presume it could be due to dirt/debris hindering movement of the bimetallic strip, however you reckon it may be closing too much which would suggest it's moving ok, albeit too far.

Do you know if it's possible to alter position of this strip manually, ie maybe bend it slightly by hand? (Hope I don't sound too much like a butcher here, I'm actually a precision engineer by day believe it or not!) If not, perhaps it's time to invest in a new IACV.

Thanks again.

Thanks for reply and advice mate. Did you have the same problem when starting ie first thing in morning? I don't have a standard d/valve but I'll have a look at the Bailey anyway. Don't suppose it will do any harm to clean the MAF and ICV too as I've never had them off!

Yup mate I have a Bailey dump valve fitted but it's been on for a good while and this problem is quite recent. Any ideas? Cheers

Hi guys/ladies,

Subaru Impreza WRX MY96

I wonder if anyone could advise me on a problem I've been having recently with idle/rough jerky/hesitant acceleration at low speed/rpm.

The car starts first time every time with no problems. When cold starting, engine will rev higher as it should. After approx 5 mins the revs drop very low (200 rpm to 300 rpm)and sounds like it's on the verge of stalling. Also if I drive away immediately after starting (gently no boost)I encounter hesitant accelerator response, and jerky movement, almost like it's misfiring. To be more precise, I press on the accelarator and for a second there is no response, then it will pick up quickly and die again. This problem is directly linked to the idle speed as when I encounter this erratic response, if I put into neutral and observe revs are sitting at 300. After maybe 10 mins of driving the problem goes away and the car drives perfectly and idles at 800.

The MAF sensor is working as it should, I tested by disconnecting with engine running, and it cut out. I also disconnected the ICV whilst running and revs became very erratic, which has lead me to believe both are working as they should. I suspect maybe the ICV is sticking and am going to start by stripping and cleaning it to see if it helps.

Just thought I'd post on here first to see if anyone could advise or perhaps have encountered the same problem in the past.

Cheers

www.scottishsubarus.co.uk located in Old Kilpatrick, Dunbartonshire.

I guess one more thing just to add balance so it doesn't seem like I'm some sort of fanboy comments

just saw your other thread .. I don't have a problem with stickered up cars, having a small few of them around is pretty cool IMHO.. But it does does shout out a bit more than a non-stickered up car. Willing to bet you wouldn't be getting so much flak if it was plain and still keeping it clean..

P.s. I'm NOT suggesting you remove them

The stickers were on when I bought the car. I'm not the greatest fan of them either to be honest, however I was persuaded by other attributes the car had to offer such as the low proven 87000Km on the clock, the STi closed deck and TD05 turbo, no rust etc. The car is in excellent condition albeit not quite the way I want it...yet! I saw past things like the stickers. My plans for future are new (smaller) alloys, crystal headlights, possible suspension upgrade from the current stock and finally a respray in a nice dark purple. The stickers do seem to attract a lot of unwanted attention from boy racers, which could give my partners view of the car being unsuitable some strength. Some little wannabe glued to my rear bumber is probably more dangerous than anything else! I have to admit though, dare I say it, the stickers have certainly grown on me from when I first bought it!

Thanks for the input guys. All your views mirror mine exactly. When you're continuously being told your doing wrong, you start to think maybe you are doing wrong! This assurance is exactly what I need and if need be I'll print this page and hand it out to all the anti-Subaru protesters...not that it would change their views right enough, but still it gives me something to go on and adds strength to my point! Cheers

Well I'm a father of 4 and I've always thought that whole 'scoobs aren't a family car' standpoint was BS to be honest - scoobs are safe, practical family saloons. They're sure footed to keep you on the road, enough power to get you out of scrapes, spacious, incredibly reliable... and you would be surprised at how quickly the continuous drone of a loud exhaust can get a baby to sleep!!! Weirdly it's the best thing I know for getting little ones off to sleep

Precisely my point! It seems to fall on deaf ears though...for some people Subaru Impreza's are rally cars and that's the be-all-and-end-all and can't seem to understand the benefits of these cars.

Having recently bought my second Subaru (Import WRX V-Limited MY96) I've come under some stick from family members/friends for my choice of vehicle. My partner is expecting our first child next month and apparantly my car is not suitable for a newborn baby as it is "too fast" "dangerous" "too loud". Some people just don't seem to understand that a Subaru Impreza can be driven carefully/safely. Who in there right mind would drive dangerously with a baby on board?! Ok the exhaust may be a tad higher on the decibel scale but it's hardly going to cause my child any harm is it? Needless to say, my Scooby won't be going and is here for keeps. The only solution for me would be to buy another cheap car to keep all the grumps happy and keep the Scooby for special occasions. I would love to hear/read views of the SIDC members on this matter. Cheers

Front passenger side strut is squeaking like mad just now! Trying to find a replacement. Considering smaller wheels either 16s or 17s as the 18s look too big plus I'm getting a bit of arch rub on full lock. The only problem is the brakes are huge! Hoping I'll have enough clearance for 17s without having to change the brakes. I like O.Z Superturismo's but I'm not sure they would suit the Subaru...any recomendations on nice wheels to suit the car? Cheers

p.s will be joining the club as a member soon...every penny is a prisoner this month after buying this

Hi guys thanks for the welcome and advice on forum. I'll get pics up today when I've figured out how to upload them on to this as they are on my hard drive at the moment. I've got a few minor niggling things to sort out on the car then hopefully I'll be able to join some of you at the meets/events.

Hi people,26 male from Scotland here new to this club and recently bought my second scooby which is an import 96 WRX V-Limited with:

STi closed deck engine

TD05 18g turbo

HKS mushroom induction kit

HKS exhaust system

8 pot K Sport brakes with drilled and grooved discs front and back

18 inch Khan alloys

APEXi oil pressure guage

APEXi turbo timer

Glad to be back in the saddle after a 6 month ban and a wrote off WRX! Can anyone please advise how to post in the "wanted" section of forums as it won't allow me to post (probably because I'm a newbie)I'm looking for a passenger side strut. Cheers