BillyBean

You know what it’s like, when you first get your Scooby – WOW.

Then, (I bet we’ve all been there) you start to get used to it and you think, is this car getting slower?
Then you drive something ordinary for a while, in my case my wifes Focus, get back in the Scooby and the magic returns.

I have had my 99 Turbo wagon for over 5 years and it’s now done over 100k miles and until recently the magic was still there.

I was sure now it really was getting slower as the boost was down across the rev range with a hesitation between 3500 & 4000 revs.
After reading this on the UK Legacy forum:-

How to Clean your MAF. - UK Legacy Forums

I thought I’d give it a go, my 99 turbo is very similar and I removed the unit completely from the tube by undoing the 5 screws ( punch out the silly pip in the middle of the screw head with a centre punch first ). Then squirted it with carb cleaner & blew it out.

The WOW factor has returned with plenty of boost delivered smoothly across the range.
Ain’t it nice to find a cheap fix these days?

PS. I am 63 years young.

Splitpin

Welcome, and I hope you're right, but you also need to be a bit careful with "cheap fixes" like that. The MY99-00 airflow meter is legendary for its fragility, and, having taken a few of them apart to see exactly how they go wrong, would caution you against believing that you've restored yours to as new condition simply by shooting some carb cleaner through it.

A "cheap fix" that results in a melted piston or clattered bearing two or three months down the line isn't really that cheap.

TBH if you've had the same sensor for five years, it'd probably be worth changing it electively, as the chances of it reading perfectly after that amount of time and use will be pretty slim, and I can see from the picture that it's one of the older, more fragile ones anyway.

GMballistic

iTrader: (1)

Welcome to Scoobynet "BillyBean" (sound's like an old Viz character LOL)
Glad to hear your Subarus running well for you at the moment and your still enjoying it. There are a few cheap fixes but unfortunately for the most part they're bl**dy expensive cars to repair unfortunately
Enjoy your car and heres a link to some sites that may interest you, Gareth

Scoobypedia | Trusted knowledge for everything Subaru | Scoobypedia / Scoobypedia

Subaru Impreza Drivers Club > Strictly Technical

https://www.scoobynet.com/technical-...w-updated.html

BillyBean

Thanks for your answers.
If I decide to fit a new one, do I have to use the "older, more fragile ones" or can I fit a different/better design?

Coc-ker

iTrader: (1)

You can fit the same maf again or go for maybe an aftermarket ecuwhich elimates it as I have. Fixes the problem permanently however is quite expensive.

BillyBean

You have to remember I come from the "if it ain't broke don't fix it & if it is broke, try to fix it, generation".

I assume Splitpins worry is that a faulty MAF can cause overboost?
If these ones are known to be fragile, then a new one might do the same anytime.
So if the worry is indeed overboost, would I be better off fitting a boost gauge?

GMballistic

iTrader: (1)

Above: Always best to have a boost gauge fitted in a turbo car IMO. It was one of the first things I did . I got mine (a Lamco gauge) second hand for £50 so it doesn't have to cost you megga' bucks to do either

dunx

iTrader: (3)

It won't affect the boost, it just won't put any fuel in when you need it....

dunx

BillyBean

Do you mean then that cleaning the MAF the way I did can do no harm to the engine?

scoobboy

iTrader: (3)

You could have done damgae to your MAF as not really supposed to use carb cleaner as thats obviously for carbs.

I was told when cleaning my old classic to use proper air flow sensor cleaner, may cost a bit more but its specifically designed for MAF's.

Splitpin

No, as has been said the reading from the airflow sensor won't directly affect held boost at all. The key concern with a faulty MAF is that it will cause underfuelling, and in some cases very serious underfuelling. Mild cases of this will make your car feel faster, more extreme cases will cause detonation and a damaged engine.

The sensors you buy from a Subaru dealer today are a modified design which appears to be less prone to damage and degredation than the earlier version you have, so by definition you won't end up using another of the "older more fragile" ones. Provided you're using the standard airbox arrangement and a quality air filter, there's no reason to think you shouldn't get a good few years use out of one, but given the importance of the AFM to the proper running of the engine, thinking of these as long term service items might be a realistic way forward.

As said above overboost isn't the worry. The easiest "easy" way to keep an eye on the general health of your airflow sensor (and O2 sensor) is to fit an AFR gauge. If either sensor degrades significantly, you'll see a change in the way the gauge behaves under boost. Then you need to work out which one's on its way out

Most of the stuff sold as "air flow sensor cleaner" is just brake cleaner/carb cleaner/alcohol/random other solvent popped in a little bottle with a label on it and sold at huge profit margins. Some people will buy anything if they think it'll save them a few quid!

scoobboy

iTrader: (3)

It costs more so dont know what your getting at when you say Some people will buy anything if they think it'll save them a few quid as obviously it cost me more to buy???

Dont think it has the same contents as looked them up and compared the 2 cans before

BillyBean

Thanks for your replies everyone.

Splitpins advise to fit an AFR gauge seems a sensible one.

What do people think the reason to fit a Boost Gauge is, purpose or just to look cool?
It is a serious question.

Splitpin

I wasn't referring to you specifically, but more to the chain of events we've seen here more than once in the past where owner advised to replace airflow meter comes back telling us he's bought some MAF cleaner for a tenner on eBay. Under those circumstances, a tenner sounds cheap if you think it'll buy some magic stuff especially designed for MAF sensors and therefore save you £90+.

I'd be interested to see a description of the contents of a bottle of "MAF cleaner". The last eBay sample I saw, the label had been printed on an inkjet and contained exactly four words - "Air Flow Sensor Cleaner", while the contents smelt exactly like isopropyl alcohol.

The main positive reason to fit one is to check your car is holding the correct amount of boost and isn't spiking/overboosting. However, IMO a regular spring driven or electronic gauge is of very limited use if it doesn't record/log.

Also - re. my earlier response, you need to be aware that the AFR meters sold to clip onto the stock Subaru narrowband sensors are, as I mentioned, handy diagnostic tools for monitoring the general health of your MAF and O2 sensor, they are not capable of displaying a truly accurate air:fuel ratio in the manner a wideband does

scoobboy

iTrader: (3)

Ahhhhhh get where your coming from now.

Saying that, this can was not purchased off ebay and was from a reputable retailer who informed me not to use carb cleaner as this one is specifically for MAF's.

Ill paste the contents of the can tomorrow lol, maybe its just is a few non purpose additives added though lol and he just wants to charge me more.

BillyBean

Do you think this gauge will do the job, if nor what would you recommend?

Clear Blue Stepper Motor AFR Air Fuel Ratio Gauge on eBay (end time 03-Dec-09 18:23:35 GMT)

What is involved in fitting a wideband one?


PS. Thought you might to see my sunny day car :-

carl heath

it get used much then mate ! lol


i cleaned my maf once on my 02 sti and cant say there was any change at all.

GMballistic

iTrader: (1)

Can't answer your wideband fitting question sorry but just wanted to say I like your "sunny day car". What is it? MG-A?? Did you restore it or buy it like that? Looks lovely in the photo eitherway Billy

BillyBean

Thanks, its a kit car replica of the 1953 equivalent of the Scooby. an MG TF.
I bought it a few years back and have replaced/improved quite alot.
Ford pinto engine, MGB back axle, Spitfire front suspension, and other recycled parts.
Like the Scooby, great fun but with easy to understand and fix technology.

GMballistic

iTrader: (1)

I thought it was an MG. I used to work at a classic car restorers and we mainly did MG's and Triumphs. Although we did have an Aston and Ferrari Dino through our doors. Working on these type of cars is great IMO and much better than nowadays when it seems you need to plug a laptop in to the car just to tell you whats wrong.
I'd love to build my own car oneday.....maybe an MGB GT V8, with the more modern MG RV8 front & rear wings on it, MGC bonnet and a TVR 4.5 V8 engine to make it go like a rocket Sound good??