zhastaph

History;

I've been having problems with her hunting on idle (700 - 1000 rpm), but only after she's been given stick. This also settles down after she's been idling for about 10 seconds. So I've suspected the MAF.

I've just fitted a knock link, given her some stick up and steep hill and as soon as she kicks in on full boost the knock link lights up like a xmas tree. (Quite a frightening thing to see )

I've taken the MAF out of a MY00 and fitted it to the RA. I've taken her out given her some stick up a hill only greens. I've then taken her to the original hill I tried earlier and given her stick up there, I've had mainly greens, the odd amber and then at one point big red This I'm putting down to fuel at the mo, mainly cos I got STP Power Booster in there as an OB and am not even a little bit convinced it's any use, I'll be ordering some Millers tomorrow.


Questions;

1. I have reason to believe that this MAF could have been faulty all the time the previous owner had it (about 1,500 miles), cos it suffered from the hunting idle all the time he had it, which he thought was normal (remember it only happens after the car had been abused after a period of time).

Is there likely to be any long term damage to the engine that I should worry about?

2. Although knock link activity looks a billions times better, I'm still getting some DET, is everyone in agreement that this is more likely to be down to fueling, or is there anything else I should be looking for?

3. The MAF I took out of the MY00 is a 4 pin MAF. I've seen posts stating that the 4 pin MAFs are the newer ones, does this mean that this has been replaced in the past and is the newer more reliable type?

Many thanks guys.

zhastaph

btt

greasemonkey

Could have been iffy before that then.

Maybe, but it's not worth worrying about, because, short of taking the engine to bits and looking at/measuring everything (which will cost you as much as a new engine to have done), there's no practical way to tell.

In the meantime, do everything you can to make certain the engine's in good nick, which means cambelt change (if you're not certain it's been done in accordance with service intervals), fluid/filter changes etc.

It's possible that your KL is being a bit oversensitive, but it's safer to assume you're seeing genuine det until you know otherwise.

Has the car been modified in any way (boost controller, modified ECU etc. etc.)? If not, it's most likely to be inadequate fuel causing the noise, so get some proper booster sharpish and see what that does. There are other less likely causes (unmetered air leaking into the inlet manifold etc.), but cross that bridge if you come to it.

Could also be that the MAF sensor you've put in is also undereading (albeit to a lesser degree), so it'd be worth putting a "proper" new one in.

Can't remember for certain which way round it is, and if you think I'm going out to look now you've got another thing coming!
Will answer this one tomorrow if nobody beats me to it!

Either way though, as stated elsewhere you're much better off shelling out on a virgin MAF sensor for it. That way, you'll know it's the new type, and you'll know it's reading properly.

WREXY

Yes the 4 pin MAFs are the newer types. But it doesn't mean they can't become faulty. Overfilling with oil, or even some oil contamination from the air filter, or vibration can cause them to stuff up.

As Greasemonkey says, change the MAF for insurance. Your car, being a JDM, will need Optimax and octane booster for peace of mind from det. If you get sick of adding booster, I recommend an Ecutek remap so as your car will be made safe to run on Optimax alone. The ignition map on the JDM cars run right on the edge, so for any small reason, such as a slightly failing MAF or even slightly lower octane fuel, you could very well get detonation, hence my recommendation for a remap to give you more leeway.

One other thing. The Knocklink can pick up a vibrating heat shield. Check that no bolts are missing or that it's tight. There was another fellow with an STI on here that was experiencing what you are and it was just the heatshield. A bolt was missing. Once he replaced the bolt and tightened the heatshield the Knocklink went quiet.

zhastaph

Thankyou for your input guys, it is appreciated.

TBH, the MAF has come out of a year 2000 model so potentially could almost be as old the other. I'm gonna be ordering a replacement one from Subaru today. I don't have a local scooby dealer so I'm gonna order it by phone, any recomendations for anyone decent, or should I just phone Sparshatts???

This too was my thought, I've only just fitted it and it's turned up to max sensitivity, so what do you do, turn it down and pretend it's not there??? So yup, I'm just gonna assume it's genuine det till I can see some sort of pattern to it that might tell me otherwise.

It's had a full decat, but is otherwise standard.

Yup, agreed. I ordered a job lot of Millers last night.

This is my long term plan, at the mo I've stretched myself to get this car and I tell got the UK Turbo too that I'm gonna have to sell first.

Fanx guys.

The_Judge

So you won't be recommending STP Power Booster then...

Thank God for knocklinks, eh?

zhastaph

It does say "Power Booster" on the bottle, that says it all to me. Shoud say in small print on the bottom, "designed for Citroen Saxos".

Oh yes!!

The_Judge

lol, or Nova SRs...

Abbylad

iTrader: (4)

Millers is pish aswell IMO, try NF Race instead, miles better

greasemonkey

...but difficult to obtain ATM. Millers is likely to be far more effective thant this STP stuff, which is the important thing...

zhastaph

Yup, most definately agreed. New MAF turned up today which has been fitted, but the Millers is yet to arrive. And guess what ... Scoob hasn't turned a wheel, I've been very restrained even if I have to say so myself.

greasemonkey

Nowt wrong with restraint in the circumstances. Much rather see you doing that than have to point you in the direction of an engine builder next week.

The_Judge

A tad harsh there. It may not be as good as NF (which I haven't tried due to the shortage), but it's not bad. It certainly quietened my knocklink down, and allowed me to up the boost from 16 to 18psi. It also seems to have allowed a tad more advance, and my mpg hasn't changed, even with the increased boost/fuel/performance...