Quick ASV question...

[SuBrat84]

Okay.. so the ASV on the drivers side of the 84 brat is creating a very loud noise that I initially thought was bad piston rings.. However.. if I plug the hose going to it, it quiets right up. What I'm wondering is if I plug it off with a quarter or bottle cap or whatever.. do I need to plug the air box off too? and will I still be getting enough air from the passenger side ASV to not have to worry about my CAT melting? Thanks!

[Subaru_dude]

I just thought I'd respond cuz nobody else did.... lol but I don't really know anything about EA81, and not very much about EA82s for that matter. doesn't it make the car run cleaner?

 

Jordan

[BobBrumby]

yeh plug where it used to get air from the air cleaner, or else you have the possibility of feeding your engine dirt once you do some offroading. Get the rubber reducer from top of silcencer and put it on the valve, once silecncer has been removed. Then put a spark plug in the other end of the reducer and its blocked.

[jeffroid]

I wish I could help and I'm glad 'dude bumped it back up because I have the similar issues with my '83 wagon.

 

I disabled my ASV a while back because I thought it might be causing some problems I was having. Thing is, mine was on the passenger side, not drivers, and doesn't appear to have the black plastic silencer thing that melts when things go haywire. Whereas on my OTHER '83 wagon that is now a parts car, the ASV was on the drivers side and did have the plastic part that melted, but that was a long time ago, long before I stumbled across this board.

 

Anyway . . . I have the same question SuBrat84 does. The wagon is running crappy again, and some of the posts lately make me start to wonder if I've melted my cat. I still have pulses at the tailpipe, but I can hear the cat popping and cracking as it cools when I shut the engine down. I don't recall hearing that to the same degree as I do now.

[NorthWet]

Before this thread, I had not heard of any problems with catcons because of eliminating supplimental air. Although I will not dismiss the possibility of this happening, I think that it would be highly unlikely. On my Cal-spec 82, the ASVs are only activeated for the first 2 minutes or so after startup. May be different on other versions of feedback-carb equiped EA81s and probably is different on nonfeedback-carb'd models. This activation is meant to handle the time between startup and the catcons getting warm enough to be effective (and the EGO sensor, too). Supplimental air after this time would screw up the EGO/ECU feedback loop.

 

Supplimental air in a nonfeedback system should only help insure excess O2 in the gas feedstock to the cat so that oxidation can take place. This oxidation will INCREASE the temp of the catcon, so lack of supp-air should tend to keep the catcon temp lower.

 

It is still possible that your catcons are plugged... I have seen some bad cases where the engine burned some oil and the residue plugged the honeycomb. But plinking and clinking from catcons is pretty common, and is often the heatshield expanding/contracting at a different rate than the body of the catcon.

 

My 2 cents.

[SuBrat84]

The 84 Brat has 2 ASV's.. one on each side.. the drivers side was making a loud noise that I initially thought was bad piston rings until I found the ASV and "plugged" it with my thumb. It turns out that it was actually my timing off about 6 degress.. give or take.. Getting my timing closer to 8 degrees BTDC made a lot of the noise go away. Apparently the timing was causing a misfire on the 2 or 4 cylinder thus the noise coming from the ASV sucking too much air. I need a better timing light though so i can get through emissions.