S2v'sRS2 MAF

[Animal Mother]

Forget the dirty MAF nonsense - I'll bet its out of calibration (unless its connector is real bad).

You don't believe in the dirty MAF thing? I thought dirty MAF cleaning was a given on the forum for sorting problems etc?

[S2central.net]

I can believe in it for circumstances where someone has overoiled a K&N filter that has mooshed its way onto the hotwire filament, but the normal MAF cleaning sequence triggered by the ECU after shutdown by allowing a high temperature burn-off pulse is more than ample to clean off any normal road grime or dirty air that has made its way past a good filter. The ECU does this EVERY time you shut off the engine... Swilling it round in a pot of IPA once a quarter is going to have negligble gains - unless it is getting covered in so much oily filth on a regular basis that the burnoff sequence isn't good enough to clean it.

Paul

[Animal Mother]

I can believe in it for circumstances where someone has overoiled a K&N filter that has mooshed its way onto the hotwire filament, but the normal MAF cleaning sequence triggered by the ECU after shutdown by allowing a high temperature burn-off pulse is more than ample to clean off any normal road grime or dirty air that has made its way past a good filter. The ECU does this EVERY time you shut off the engine... Swilling it round in a pot of IPA once a quarter is going to have negligble gains - unless it is getting covered in so much oily filth on a regular basis that the burnoff sequence isn't good enough to clean it.

Paul

I'd say doing it once to a MAF which is playing up is worth a shot as it may save you a good deal of cash.

[Jamo]

I can believe in it for circumstances where someone has overoiled a K&N filter that has mooshed its way onto the hotwire filament, but the normal MAF cleaning sequence triggered by the ECU after shutdown by allowing a high temperature burn-off pulse is more than ample to clean off any normal road grime or dirty air that has made its way past a good filter. The ECU does this EVERY time you shut off the engine... Swilling it round in a pot of IPA once a quarter is going to have negligble gains - unless it is getting covered in so much oily filth on a regular basis that the burnoff sequence isn't good enough to clean it.

Paul

There are a load of S2's now with bad condition PCV systems and judging by the state of the pipes that are coming of the car, original mafs over time might be a bit oily.

However Paul is 100% right in that the MAF Bath is no real substitute for buying a new MAF!

[Animal Mother]

However Paul is 100% right in that the MAF Bath is no real substitute for buying a new MAF!

Dead right as long as the MAF is faulty. If it's just dirty (due to PCV, K&N etc) then a clean would be just the ticket. Always worth trying as the first thing to do before spending hard earned money IMHO!

[Jamo]

Dead right as long as the MAF is faulty. If it's just dirty (due to PCV, K&N etc) then a clean would be just the ticket. Always worth trying as the first thing to do before spending hard earned money IMHO!

Your completely missing the point as usual. if it playing up it needs replacing.

[S2central.net]

Well IMO - the oily fumes from the PCV shouldn't really get a chance to get as far as the MAF. Yes they are sucked into the inlet side of the large pipe that goes to intake side of the compressor. That hose is always under vacuum and so the atmospheric pressure (even in lift off condition) from the ambient side of the airbox and MAF will have the effect of preventing those fumes coming back up the MAF pipe and across the hotwire filament.

Maybe I'm not visualising what JAmo is trying to explain here, but I can't see how PCV fumes would get near the MAF - unless the PCV system was so failed that positive boost pressure was forcing fumes back up the MAF pipe. That would be weird.

Of course the TBV blows a proportion of boost pressure back into the MAF pipe during gear changes - maybe that is enough to cough some oily crap back up the spout.

It would be a very different matter if the MAF was relocated to be placed on the compressor outlet and the factory PCV system was retained. That would always circulate the PCV fumes through the MAF.

I really must get a proper venting and catch tank or drainback setup on the S2. It is amazing how big a spoonful of oil sits at the bottom of the intercooler and I am loathe to fit my RS2 IC on there until I have that solved. That will clean up the air into the engine and bring down air temps at the same time.

Paul

[gt2]

for info, the PO had cleaned the MAF. the thing was spotless, unlike the used one we swapped in (no offence mate )

I've seen the posts on dodgy connectors, disconnecting, cleaning etc of my connector has done nothing to improve the situation.

even when i didn't experience the bucking under full throttle, the car has allways felt a bit hesitant going through the rev range and frequently get the fault codes i mentioned. now-smooth, more power and no fault codes since the swap.

[S2central.net]

Your completely missing the point as usual. if it playing up it needs replacing.

@Jamo - have you changed your medication recently? Give the guy a break. It wasn't THAT long ago that you were a newbie.

[S2central.net]

for info, the PO had cleaned the MAF. the thing was spotless, unlike the used one we swapped in (no offence mate )

I've seen the posts on dodgy connectors, disconnecting, cleaning etc of my connector has done nothing to improve the situation.

even when i didn't experience the bucking under full throttle, the car has allways felt a bit hesitant going through the rev range and frequently get the fault codes i mentioned. now-smooth, more power and no fault codes since the swap.

Please keep a hold of that dodgy MAF - I want to get a few tested and get some benchmarking done so that I can build up more useful info on how to spot a duff one. Generally speaking their output voltage decreases with age and degraded accuracy. They can be recalibrated by specialists - or tested to the point that it indicates a recal wont fix it and a new one is required.

PAul

[Animal Mother]

Please keep a hold of that dodgy MAF - I want to get a few tested and get some benchmarking done so that I can build up more useful info on how to spot a duff one. Generally speaking their output voltage decreases with age and degraded accuracy. They can be recalibrated by specialists - or tested to the point that it indicates a recal wont fix it and a new one is required.

PAul

Surely one of the electronics boffins on here would be able to make a plug in tester utilising a MAF connector block which automatically reads resistance, voltage etc in order to test the MAF. I know some of you guys are technical wizards!

[Animal Mother]

Your completely missing the point as usual. if it playing up it needs replacing.

Jamo,
You can be quite an "expert" sometimes, check out your posts below, MATE!

You seem to have taken a dislike to anything I say on here when a good deal of the time I am in fact repeating something you have said previously.

Think before you comment next time and learn to fear the SEARCH FUNCTION! :mischeif:

Audible leaks, how was was this check done?

You need to pressure test the intake system as it sounds like overboost protection.

1) Pressure test the system for leaks
2) Get the Mark H intercooler mod installed on the Intercooler (look in Been There Done That section BTDT) as your bound to have a leaky O-Ring
3) Clean MAF

The hunting idle, will be the idle stabilisation valve, probably needs a good cleaning with WD40.

Also i'd clean the MAF with IPA before changing the Lambda IMHO

You'll be annoyed if you parted with alot of money for something you didnt need.

Give them a whirl, if it doesn't work then look at Lambda

[S2central.net]

Peace guys... Back to the plot - the resistance values on the MAF components are laser trimmed. The info I have on S2central is just a guideline - not an exact science.

As for electrical boffins - I have a BEng in Electronics Systems and a PgD in Digital Signal Processing but that doesn't make it easy or cost-effective to create a more reliable way to test the MAF. It is a very delicate device that needs to be calibrated. The only place I know that can do it in the UK - has the knowhow, an appropriate flowbench and whatnot is JDS Porsche. I exchanged emails last year with the dude there - nice guy - but I never found time to have a good chat and move things forward properly with S2/RS2 specific tests but I'll get there sometime this quarter - work committments permitting.

Paul

[Animal Mother]

Peace guys... Back to the plot - the resistance values on the MAF components are laser trimmed. The info I have on S2central is just a guideline - not an exact science.

As for electrical boffins - I have a BEng in Electronics Systems and a PgD in Digital Signal Processing but that doesn't make it easy or cost-effective to create a more reliable way to test the MAF. It is a very delicate device that needs to be calibrated. The only place I know that can do it in the UK - has the knowhow, an appropriate flowbench and whatnot is JDS Porsche. I exchanged emails last year with the dude there - nice guy - but I never found time to have a good chat and move things forward properly with S2/RS2 specific tests but I'll get there sometime this quarter - work committments permitting.

Paul

Sounds like you could het into a whole world of hurt trying to fully test them yourself.