Graeme Field

Dear All,

I am currently on my 3rd Air flow Meter fitted to my STi V which happened to give up the ghost yet again yesterday.
The mods I have associated with the engine are as follows:

HKS Straight Through Pipe
HKS Full Exhaust (no cat)
HKS Induction Kit

HKS Sequential blow Off Valve
HKS Air Flow Ratio module

The first 3 where fitted shortly after purchasing the car back in January.
The AFR module & SBV where fitted only a month or so ago and by this time I had gone through 2 Air Flow Meters anyway.

The first time the Air Flow Meter went faulty was in May and then in July and now in September (a 2 month gap! each time)

The car was driven quite hard last time when it went but not on this occasion only dropping down to 4th doing about 50, overtook a car about to go into 5th when I lost all power......

I am getting to the point where my garage who are doing the work and myself are unsure of
what could be causing this problem.

HAS ANYONE ELSE HAD ANY PROBLEMS LIKE THIS? or can anyone put me in touch with someone who can suggest things to have a look at?

HELP, poor scooby owner....

MorayMackenzie

Check the induction kit is fitted securely and the hoses are secured correctly.
Have you removed the blanking panels from the bonnet vents?

Just thinking of possible ways that foreign bodies water/dust could get to the AFMeter.

Moray

Andrew Dixon

As far as I know, the AFM is a pretty sensitive piece of kit. Not sure if the STi V uses a hot-wire or hot-film (more likely). Either way, if the sensor get 'stuff' stuck to it it would cause problems.

The 'stuff' could be coming from the HKS air filter which might be letting in slightly too many particles, or may be allowing some of its filter oil to escape into the airstream and clog up the AFM.

Maybe it might be worth returning to the standard air-box for a while (no fun!), or fitting a different manufacturer's kit? Or it may even be that your current HKS filter is faulty?

BTW, saw your car at the rally at New Brighton a few weeks back. Nice car!

Hope this is of some use.

Andrew.
MY97 Turbo

firefox

Hi there,

I have been using HKS induction kits for over a year (on a 97MY) with no problems.

How is the AF meter fixed down ? Can it vibrate ? Have you checked the voltage going to the sensor ? does it spike ?

My first guess would be particles - have you checked the sensor ? what exactly fails on it ?

J.

Ian Cook

The AFS was changed on the 99MY cars, including the STi 5, I have heard of at least 2 others that have had this problem, all were down to the HKS Induction kit, the gauze is too coarse apparently.

BTW I think the pre 99MY cars used a hot wire AFS and the latter use a hot film one.
Might be talking out of my a**e though.

[This message has been edited by Ian Cook (edited 06-09-1999).]

R19KET

Hi,

Ians right.Sti5 uses hot film, and it's VERY sensitive.Friend had exactly the same problem,(2 afm's)changed filters,and no more problems.

Mark.

The Yank

Here in the States, many owners of 1999 Imprezas have also had their MAF fail. The 1998 MAF was different, and to my knowledge, the 98 version has not had any problems.

All of the cars that that had MAF failures, also had some sort of aftermarket induction system. Such being an intake "pipe" or high performance filter. Owners using aftermarket "cone" type filters and intake pipes had to re-mount the MAF to the pipe. If the pipe is not secured properly, the MAF is subjected to violent vibrations. We, in the States, feel that the failures are caused by vibration rather than debris on the sensor. The sensor is of the metal film type.

If you use an aftermarket filter/induction system, make sure that the MAF is securely locked down in some fashion, so as not to move while the vehicle is being driven.

On a side note, all Subaru dealers in North America were instructed to not replace the MAF under warranty IF the vehicle is equiped with an aftermarket filter/induction system. When a MAF fails, we have to re-install the original filter box and hoses to get the Subaru dealer to honor the factory warranty.

I hope this information is helpful. The Yank.

quattro

OK guys, being one of those who has had the HKS Induction Kit installed recently on my Sti 5, I read all the postings above and spent some time looking into the engine bay of my car today. I am prepared to accept that mechanical vibrations could cause the AFM to fail, but (as it has been said) most likely only if the new induction kit assembly (which does not have the filter box any longer at the other end to support the AFM, etc.)has not been solidly fixed. A few points:

1) HKS induction kit for the STi MY98 has a part no. 1504-SF004. Same product for the MY99 (read: STi5) has a part no. 1504-SF007. I do not know whether and which differences between the two may exist, but suggest for the correct part to be installed.

2) The way the kit is installed on my car, there is a supplied (HKS) bracket which supports the new parts in a similar way the filter box would. One end of the bracket is fixed pretty near the AFM and the other on the shell in a convenient position. Also, there is a second HKS (vertical) bracket which supports the AFM and the pipe behind it anyway. Therefore, the induction kit/AFM assembly is firmly supported at both ends. This seems to me pretty solid and stable and I think if properly installed it should not and does not vibrate much. I observed relative movements within the engine bay when engine was revved to various values and there was no visible movement of the AFM or associated HKS parts. The car was, naturally, stationary.

3) It seems that some owners of the STi5 at the begining of the calendar year had no choice but to purchase and install either the SF004 version or even a complete kit for another car and then adapt it to fit the STi for a simple reason that the SF007 did not even become available till May/June (according to the manufacturer). Therefore, I am not entirely sure what and why may have happened.

4)I can, of course, only discuss HKS installation and behaviour. I presume other products of the same kind would impose slightly different, but essentially same mechanical requirements for proper operation.

5) Needless to say, if I lose the AFM soon, I will let everyone know.

q.

[This message has been edited by quattro (edited 07-09-1999).]

[This message has been edited by quattro (edited 07-09-1999).]

firefox

I always like to be difficult....

Something else to consider.... What happens if the sensor is too rigidly fixed down ? Dont forget the air box even had rubber mounts.

Bolting the MAF down too much will only allow chassis vibrations and noise to travel up the brackets and to damage the delicate sensor.

Thats of course if it is the vibrations ?

J.

quattro

Absolutely right, firefox. And being difficult is just the right thing to do.

Too tight is as bad as too loose. I am pleased to tell you that the way the HKS kit is mounted on my car is just the right amount of movement.

Once again, the proper kit will have ALL the parts necessary to put minds at rest.

q.

Graeme Field

Hmm.. ok so if I was to change the Induction kit, which one should I go for??

K&N , PiperCross , (Not RamAir I think..), ITG ?? ??? ???

quattro

Graeme

Why change at all? Are you certain you have the correct HKS kit on your car now and whether it has been correctly installed with the appropriate parts? Further communication with HKS revealed that the MY99 (i.e. STi5) induction kit had speicific brackets designed in order NOT to have AFMs suffer from excessive mechanical movement. Also, the sponge filter element in their induction kit lasts at least for one year if not longer before it may need replacing (even with a high mileage).

Not trying to make you change your mind, but this bbs seems to have an incredible influence on people in making them change things a bit prematurely. (This will now cause some flack!!)

Good luck and choose well!

q.

Ian Cook

The thing to remember before changing what you have is as Quattro and Firefox have said, make sure you have the right bits first, if it doesnt work go back to the supplier and ask them to sort it. Dont just change to something else without trying this approach first.

I dont remember any comments being anti HKS as such, if there is a problem with something then it has to be fixed, if the Induction kits that have been fitted to 99MY/STi 5 cars are faulty, or have been the wrong ones up until now, something should be done, would you be happy to pay out 200 quid for a new AFS every few weeks ?

As for only a couple of companies being "approved" thats not true. Which other companies get mentioned on here? Who has experience of other companies products? There are 1400+ users here, they dont all use the same companies to modify there cars. Until posts about other companies product appear, how do we know to talk about them ? If all we read is bad about a companies product, and we dont hear a single positive comment, then of course there will not be much support for them. It does give them the opportunity to turn things around, and improve. If on the other hand, a company produces a good product then it will get recommended by the users of the BBS. It is all about not making the same expensive mistake as somebody else.


Oops forgot to say i do have the memory of a goldfish so i might be wrong


[This message has been edited by Ian Cook (edited 09-09-1999).]

firefox

Hey Quattro,

I agree with what you said about people changing there minds..... but experiences from other people is a good thing - but not the be-all-and-end-all of it.

I have also noticed people are very anti-HKS (amongst other companies). I've notice only one or two compnaies are approved of on here - Even when some dont know what they are always talking about.

J. (now I will get the flack)

[This message has been edited by firefox (edited 09-09-1999).]

firefox

Ian,

Many words of wisdom... ;-)

I agree with you completely... if there is a problem with a specific instance, then that problem should be resolved.

Everyones opinion of subject matter is different. That was my own personal opinion on what I have seen and "felt".

I am not going to start a debate on which companies/firm are good or bad. I have not had any bad expereinces with any companies, to be honest I havent had any good ones either (do all the work myself). As such I am not going to start mentioning names.

I was just trying to point out (similar to yourself), that there are plenty of other firms out there (perhaps with more experience and better merchandise) that can be used to "improve" on certain aspects of the Scooby. But all I see knowadays on here is that a select few companies get all the credit.

Perhaps that is becuase of poor marketing and advertising by these "unknown" firms - Or people take a verbal recommendation as the gospel and the be-all-and-end-all.

I would like to say: Listen to what people say - Experience is the best form of knowledge. But remember there are other avenues out there. Just because a person suggests a certain product or company, it doesnt mean they are the only one doing that product - You might find a better piece of kit or service else where.

Anyways - This thread is going now where... LOL

Tara,

J.

Graeme Field

I have located my old Invoice from TDi, which is where I had the full drager exhaust system, downpipe and Induction kit fitted and it clearly shows the stock reference as:

1504-SF004 - SPF GC8 - 155.00

Now this clearly shows that I DO NOT have the correct one for the STi5 on my car!!
So should I complain to TDI or HKS or both in that I have been supplied the INCORRECT one for my car which is causing the AFM to go faulty... and at 300quid a time it isn't cheap!

I'd like to thank everyone who has replied to my original post especially, quattro, Ian Cook, Firefox and all others and to those that may still give me further info / guidance.

My Garage has sent an email to a guy from HKS Europe to get some information as to whether they are aware of these problem and to find out how they plan to rectify them. Could this be the reason for the later model (SF007)?

quattro

I am really no longer sure how many more experiences one needs in order to establish a pattern of 'thread developments' on this board.

Step one: someone opens a debate over a technical problem, observation, etc. (which is, it seems, the purpose and intent of the exercise)

Step two: some people (usually the same ones) post constructive, experience based, comments in order to assist the subject and the original question and the member posting it.

Step three: things get out of hand and end up being a right/wrong 'dialogue' such as one just witnessed above.

Footnote: there is absolutely no question that some products seem to be liked (much) more than others. Why? My analysis says it is the good old 'value for money' (as if such thing ever existed with goods which are all expensive enough to be a loss the moment we buy them and never get the money back...) syndrome. To paraphrase firefox and Ian Cook (nothing bad on my mind, honest!) no one is anti-something, but too many are pro-something else. Do we really need to know why?

Adminstrator and Webmaster had some interesting things to say elsewhere today. Perhaps they do have a point, after all.

Nice weekend.

q.

PS. This was posted BEFORE I saw Graeme's most recent posting. I am not sure what you should do, Graeme. Establish the date of your invoice and it may be that when the parts were sold to you there was no SF007 yet (see my earlier reply to your question). I would not be surprised at all that what you were supplied was yet another example of 'do not worry, it will fit' approach which is so common in the motor trade and we all fight against. I would pursue HKS in Cambridge, explain the cricumstances and hope to get help (read: correct parts) from them.

Over and out on this one!

[This message has been edited by quattro (edited 09-09-1999).]

firefox

Hi again,

I have the number for HKS Europe, I have spoke to them (Michael) several times. He is very keen and focussed on customer relations and opinions.

Remember TDI are seperate to HKS, they are independant reseller. HKS have now established other resellers.

Give TDI a call see what they say.... When you dont have any joy, give HKS Europe a call, from my experience I would reckon they would be very sympathetic and helpful - Give them a call and explain whats happened.... maybe blag some goodies off them..

Cheers,

J.

ps - Mr Q - Well said, I believe this BBS has gone a little bad (yes - perhaps I am to blame like most people). I would like to see it become more focussed, more about meets, cars, technical experiences..remember its an SIDC BBS.... its for the club.. Maybe it might become a private BBS for club memebers only? *I hope not*

DYNT

Hihi ... is very common for the AFM to indicate faults to the ECU if there is an air leak somewhere along the piping.

Do check all the piping joint .... this has happen a few time to my customer car.

Sometime ... the trouble code indicate Idle control valve too.

Does the engine died of when u brake or change gear??


Cheers.

Rannoch - Have a look at the HKS Air Flow module then ... could be that too.

[This message has been edited by DYNT (edited 26-11-1999).]

Trout

iTrader: (1)

Well....

....as some of you may have read I have had a cold start problem with my Scooby.

0-3000 miles standard

3000-6000 HKS Induction Kit (004) HKS Hiper Exhaust

6000-11,000 standard (neighbours complained of noise)

11,000 -12,000 HKS kit on again for Donington and Santa Pod.

Three months ago a cold start problem occured at about 9,000 miles.

Now I have the Training WRX manual I have diagnosed this as a faulty, although not failed, AFM. Bugger.

I have spoken to Park Lane - they have had a number of AFM failures - some with HKS kit on and some without - apparently it is the same as the Legacy partno and it is failing on them too.

Poo.

Anyway - I will replace it and take the HKS kit off to see what happens.

Graeme, what are you doing? HKS are saying the only difference between 004 and 007 is the deflector plate that reduces air flow anyway

Final question - as it is merely misreading, not failed - how can you clean a hot film sensor?

Cheers,

David

Trout

iTrader: (1)

DYNT - no it is only cold start problem, otherwise car is running very well - pretty quick compared to other STI/WRXs so fault does not seem to be too serious! Yet

David