ArcticSteve

Like the title says I experienced a total loss of power in my S2 today. My hot idle while stopped in traffic has resulted in some near stalls lately, and yesterday just after a cold start I stopped to talk to a neighbour on the street and had to turn the motor off because it was stumbling. Ran fine after that.

So today I start it from cold. Usual good start and I let it idle a few minutes. I took off and went down the street. Went to take off from the stop sign and had a wild idle and absolutely little or no power. Didn't really think I was gonna get back to the house as I had to pull over and since it seemed like it was gonna die I shut it off. Waited a minute, same sh*t happening, but made it home. However, there was this mega clatter coming from under the steering wheel it seemed. Being late for a business appointment I just switched cars and took off.

Now I get back home and turn it on and same wild fluctuating idle from 250 rpm to 2200 rpm approx., no input from the gas pedal and the same really noisy clatter. This time the hood is open and the clatter seemed like it was coming from under the brake booster. Certainly not the motor itself. Turned it off and back on and everything is back to normal.

My vacuum lines look original. I dunno. Very odd.

Thoughts anyone ?

krazykarl

A bad AFM can sometime cause running issues at the ECU gets bad information about air flow.

ArcticSteve

Thanks for that. But this very loud clacking from under the break booster area is part and parcel with the wild surging and no power. Is there some kind of idle control motor in that vicinity run from the break booster vacuum?

Well I just went out and started it up. After about 5 minutes of idling OK, the clacking started up and then it started to idle surge and then it died. Started right up, same thing, but I could rev it up, but the idle soon dropped to nil when I let off the gas and it died. Didn't hear the clacking this time, but it was pouring rain all of a sudden so one of those days I guess.

No harm in taking the AFM apart and cleaning/testing that. Car has 210k miles on it. Motor has 35K miles on it.

Any chance this is a DME relay issue. Previous owner had a spare. Don't know why. It didn't change anything.

krazykarl

The top of my S2's engine is apart at the moment and I can't think of anything being below the brake booster

ArcticSteve

Appreciate the pic Karl.

I'm gonna go with what you suggested; the AFM. I'm gonna pull it off and test it. Probably clean it as per Clark's AFM page. Logic would have it that after 210k miles it might be messed up.

As for the clacking. Really weird. Thought that it might be some kind of throttle assist motor, perhaps vacuum assisted.

Just started it again and drove it into the garage. All is normal, however did not hit the road. I'm assuming a messed up AFM could conceivable go from bad to good to bad to good and so on.

Will report ultimate result. Thanks

krazykarl

I know someone else on the forums mentioned having a bad AFM where the spring no longer kept the proper tension on the flap. I believe he mentioned that when he removed it he could here the plate swinging around.

ArcticSteve

After a few brew to restabilize my senses, I located the "clacking" sound. The louder the "clacking" the worse the idle.

Here are a few pics. Bosch number # 0280142151

ArcticSteve

another shot at the pics

I should say that this electrical device runs by hose straight into the intake manifold.

ArcticSteve

Ok, I think this above pictured device is called a Vapour Canister Purge Valve.