changed to an Apexi induction cone at the weekend.
nicely supported and its not oily so MAF friendly.
anyhoo, remembering that there was a simple test for MAF sensors, last night I disconnected the MAF and next thing you know the engine has a hiccup and splutter but carries on runing.
Holy sheet!
not good.
I then ran a diagnostic and low/behold its flashing 23.

now Im pooping my pants.
quick reset and Im reluctant to drive on boost in the morning to work.
quarter hour later, mate pops round with a 99scoob and induction kit, blimey if his doesnt carry on running after disconnecting and flash 23 on the ecu!!
so, this morning after the 50 mile journey I decide to disconnect again.
engine cuts out straight away.
quick diagnostic check and its flashing a-ok.



either:
a) by disconnecting the maf to fit the filter at the weekend had caused the maf to require reset and now its done its all ok again.
or:
b) fitting the filter had ballsed it up and now I need a new maf.

questions...
should it require a reset after disconnecting the maf?
I have absolutely no doubts about the filter integrity because its a dry filter that has excellent flow/filtering properties.
I cant be 100% sure but I may have cut the engine and restarted before carrying out the disconnect test, would this have made it not cut out?
sorry, I know its been done but it was freaky and worrying at the same time.

Andy

 

Andy,don't forget i now have the diagnostics to check live readings whilst the car is driven to find these faults!!
Speak to Ian as he knows the score about my new business venture.
steve

 

Steve,
please pm me your number and Ill call you this morning.
I called Iain about it last night and he does have a spare MAF but it just seems a little odd with the turn of events.

 

Andy , give steve a call .

He's got a right spanking bit of kit which you can plug in and get loadsa live readings whilst driving

his call out charges are well reasonable

 

got my new phone with me so need a pm of his number!!
or the garage number, either way Id like (if possible) to stop by on my way through tonight and get a reading before popping round to yours if I need a maf swap.

 

hi peanuts
your maf might of gone already and the ecu didnt recognise it until it was reset, buy a new maf and it should be fine

 

thats what Im thinking, although this morning it was playing ball, I think...
Ill get a shot on a select monitor somewhere to confirm its demise...

 

Must sort out your commision Ian!!

steve

 

steady now


fairs fair though

 

 

cant fit me in tonight Steve, no?

 

Peanuts, can I ask why you went for an Apexi cone? It wont give you any more power, they are pointless! Any tiny power gain you might see on a RR is probably just because its causing the MAF to lean out the mixture.

When you say you dont doubt the filter becuase it has excellent filtration, do you know the micron size of the filter mesh? These things genreally claim more power from the simple equation that they let more air in, and not through the increase in surface area. MAF failures seem to occur for a few reasons, the key ones being vibration and contamination. Yours is dry, but may have been gummed up from a previous filter. Vibration - the K&N is good because it has a mounting bracket to the inner wing, to stop it moving. Does the Apexi have one?

Also, they promote heat soak (unless you have a cold air feed and boxed the filter off)

But back to the MAF. Unless you manhandled the MAF when fitting the Apexi, its unlikely to have damaged it in the very short term. Mor elikely it was dead anyway.

When fitting a new MAF, its best to reset it. Also a new filter as the ECU may need to adjust for this. If you have reset the ECU and the idle is all over, the MAF is probably at fault and was buggered anyway.

Just buy a decent panel, or you may well be buying MAF's more regularly

MB

 

I bought the apexi cone on the strength of a few tests that I read whereby the apexi came out trumps in filtration, ahead of K&N, blitz, hks and itg.
it also had higher air flow properties as well.
The survey is available on the mk IV forum I believe, but it might be gtr.

The idle is sound, it was the maf check that failed, ie disconnect the maf when idling and see how the engine performs.
That made me look at the diagnostic and it flashed up maf, quick reset later and it was showing good on the ecu.
came to work this morning, nice and steady, no boost.
engines nice and hot, disconnect the maf on idle and it killed the engine straight away.
sign of a good maf.
my concern maybe that because i didnt reset after fitting the filter that it was running on panel settings, which is what I had i there previously (see for sale section).
I am going to get apexi ecu fitted and mapped and if you look into it, there is a special rating on the ecu for apexi cone filters.
Thats why I bought it.
cheers for the ideas

 

Get the maf tested first before you buy one like I did. Ive been having idle trouble and everyone shouts maf, so I buy one and the problem is still there, so that was a waste of money. In my case its either lamda or idle control valve. By the way my maf always passed the pull the plug test apart from once and then it was still deamed as working fine with no problems.

 

Ah, I see - no idling issues. Must read better. Yep, a reset is best after changing something like that. The ECU will learn things like new sensors, but more slowly than doing a reset.

Still be interested in the mesh size if you have info, I could never find stuff on the Blitx one (probably becuase they're hiding it)

Filter will work better with a remap

MB

 

If you unplug the maf with the engine running then of course the ecu will flag a maf fault cos you disconnected it with the engine running ... nothing odd about that.

Dependant on the fuel learning, a car with a disconnecetd maf will either stay running or stop, unfortunately this is not necessarily a good cherck for a failing maf, if you leave it connected, do a reset after checking the afr and fuel correction then check again a failing maf will show lean running with high correction.

The best test is to use a good (ie wideband) afr meter and check it before and after reset with the lambda sensor disconnected. then you will see actual afr corrected by the ecu long term learning and uncorrected with no ecu learning. Normaly a car would idle and drive at or about stoich however with a contaminated maf you could see up to lambda equals 1.2.

The ecu is designed to run the car without the maf connected btw, its called limp home and then it uses the map sensor only to pick a point but does rev limit to about 4000 rpm.

assuming we are talking about a MY99-00 GC8 of course.

bob

 

Thanks guys,
bit the bullet and got a new sensor.
having a select mnitor test today and will get both sensors tested.

good points above, thanks again

 

See you round Ian's place 2nite Andy...i have told him to get the kettle on

steve

 

game on Steve,
Ive got a new sensor in there now, but hopefully we can get a shot on all the ones available and launch the gash ones.
at least we will know we have some good spares
see you this evening (about 6).
I think Mike wants to come as well so there will be a few scoobs at Iains tonight

 

Hope he has 'good' neighbours who fully understand what a decat sounds like

 

decats with induction...?



oh lordy!!

 

i think they hate me , i now get visits of up to 7 scoobs at once (plus mine )

all with bl**dy noisy exhausts !!!

 

that gadget is tip bleedin top.
fully boosting the **** out of it this morning on the way to work, and she felt good

 

Another happy customer then