yellowducman

I'd bet it is the Mass air flow also. Mine does the same thing when driving on certain downgrades. Does it at the same place on the same roads every time. There was a lengthy thread a while back of someone having the same problem and it was the Mass air sensor.

boxsey911

I've been meaning to look at this myself and finally got around to it today. My what a mess I found from previous work. The insulation had been removed from the lead as recommended by the TSB but they have half destroyed the plug in the process! So not only did I cable tie the lead to the plug (accoding the TSB instructions), I had to cable tie the plug to the AFM socket. I also found that the breather pipes that the plug needs to be clear of were routed wrong. They weren't even in the clips that are provided on the fire wall. So that had to be sorted too. The result was a 30 minute job turned in to a couple of hours! All sorted now though .

p.s. tip for anyone doing this job - in addition to removing the air box loosen the hose clip too and remove the AFM so that you can see what you're doing.

Livefreeandrive

My belief is that there are a lot of critical things going on in that (hard to access) area that can really screw (ruin your day/week/month/marriage) with these cars.........my bloody knuckles are proof!
I wish I could remove 10 19mm bolts in the passenger area and get to that STUFF!=vacuum hoses, connectors x20, power steering junk, oil sender.................WTF!!
Happy Saturday! Gulp...
Steve

AB-Oz

Well I got into solving the problem on Saturday.

Pulled the airbox and filter, gave the K&N air filter a clean and recharge, lucky I had the kit as my bike has a K&N too.

Got the AFM wiring harness detached and lo and behold, my work to fix the issue as per the TSB had been undone by the dealer at the last service, the cable tie keeping it tight was gone, leaving it with the potential to touch the vent hoses.

So I put some heat shrink on the wires to protect them a bit, re-tied the wire to the plug, and whacked it back on.

Drove the car a few times over the weekend, no repeat of the problem, and this mronings commute was problem free.

Next service I will have to expressly tell the dealer not to fiddle with the plug and its wire.

boxsey911

Good new AB

I guess the reason this TSB works is that it stops the AFM picking up a signal from flow in the adjacent pipes. Do I guess right or is there another explanation for the mod?

gchristofi

The AFM is a mechanical flap that translates air flow into an electrical output. It can't pick up flow from adjacent pipes but it's probably some electrical/static interference that is created if the sensor wires touch the breather hoses...

Livefreeandrive

What exactly runs through the "engine ventilation" hoses?