Just need confirmation
 

Hi guys.

So I've noticed my MY99 wagon is acting a little strange.

The engine revs drop down to about 100rpm as I'm slowing down and down-shifting (stopping at a red light, etc). This doesn't happen every time I slow down but it happens more often than not. After it drops to around 100-300rpm it goes back up to around 900-1000rpm.

When the car is on boost, it kind of hesitates and then comes on slightly, then hesitates again then comes on full boost. It's weird.

The car smells very strongly of petrol even after a short drive.

I noticed the rev drop and petrol smell quite a while ago...shortly after my car was serviced my RMS. I only just noticed the hesitation just recently though.

I've come to the conclusion that it is probably my AFM. I just need a confirmation that this is the correct diagnosis. I've been driving off boost since Wednesday just in case.

I have no idea what panel filter is in my car. I have an APS cold air intake.

Any help would be appreciated. :)

Does sound like either an AFM or O2 sensor has given up the ghost although I'd be more inclined to say O2 sensor as the symptoms of an AFM are usually more severe than what you have described.

I'd get it into your preferred workshop for diagnosis ASAP before it gets any worse. In the meantime if you know someone with an AFM you could borrow to swap over and test with I'd give that a go.

Afm

Is it hard to change the afm over? I might go out and buy some contact cleaner to try on mine first...

Not hard to change AFM, but you will need Torx fitting for your screwdriver.

When was the last time you checked/replaced your spark plugs? My car had a strange issue coming onto/during boost, where this was the problem.

I assume they were changed last service which was about 3000kms ago... around February I think. I'll have to check receipts. Does that explain the revs dropping though?

P.S. Don't drive it hard until it's sorted or BOOM!

[QUOTE=Rossco;458249]P.S. Don't drive it hard until it's sorted or BOOM![/QUOTE]

Yeah I've been driving like an old man for the past few days. I hope it's easy to sort out because I don't have a lot of free time. So my best bet is contact cleaner and see if that works. If it doesn't I'll try a used/new AFM... And if that doesn't work it'll have to go back to RMS. Where is the O2 sensor?

The o2 sensor on my 99-00 only trims the cruise AFR's it won't make it run rich constantly.

Is your temp gauge working? because a dead water temp sensor WILL make it run in cold start mode constantly (very rich)

Temp gauge is working fine. The car has a Link G3 ecu by the way.