AIS and reed valves, Q's an need A's Please

[Guest Skip]

My Brat suffered the all to common failure of the reed valves in the air suction valve ( ASV).

The silencer soft ball melted down and the Hicrappy took the big hit.

Glued the throttle plates open, lots of fun.

 

Fast forward, got another carb, tore it down and "refreshed" it (couldn't afford a kit so I put the used stuff back in) Swapped carbs, runs great, even idles down now (was stuck at 3 grand, secondary would not close.) note: when doing this make sure you knock the pin out blocking egress to the idle mixture screw.

 

Q1 - has anyone had any luck cleaning these reed valves in the ASV? Or are they usually FUBAR?

 

Q2 - I need to get the Brat past the emission cops. Well - the only manual I have besides the worthless " Keep your Sube alive", is another worthless pub made by people who should stick to making underware.(Haynes) The former says -too complicated take it to a shop -phewwie.

The latter says this air injection system (AIS) only functions when the engine is cold. Is this true?

 

My emission test is only done on a warmed up engine (closed loop as they call it). So will this EA81 pass without having the AIS system functioning. Well half of it anyway.(assuming all other systems are a GO, it does have a good cat, but no ECU and thus no duty solenoids connected to the carb).

My guess is yes, has anyone tried and succeeded.

 

Q3 - Does anyone know what I am talking about?

 

Thanks for reading this far.

Any intelligent replies are greatly appreciated.

Batteries not included, no warranty expressed or implied

[Guest qman]

Skip, I just repaired the same thing on the '84 coupe. I found out that it injects air into the exhaust and should not in any manner blow air out. I would also assume that it function all the time. Why just at start up? It is a vacuum controlled valve but still. I just added a used valve and repaired the rest of the hoses.

 

A great fix for the stuck wide open secondaries is to take a small amount of screen door repair screen and cut it to fit the O.D. of the carb and place it over the opening. Then install the air cleaner to hold it in place. It saved two more carbs before I got the problem resolved.

 

Qman

[Guest moosens]

#3-yes,I know what you are talking about.<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/embarassed.gif ALT=":o">

 

Opinion from this emmisions bandit says the Subaru 1.8 can be made to pass emmisions in CT without the stuff.BUT...the day may be coming soon when that is no longer the case.They may start looking at all hoses,etc.If numbers are ok maybe then it won't matter.

 

You DO need that '86 FSM don't you?

"Snow Worries" has to make it out of the shed before the snow hits the foot mark.

[Guest Skip]

Qman, thanks thats a great tip on the screen, problem I have is the flies are already in the house - so to speak.

 

Underware claims the ASV is controlled by a vacuum from a thermovacuum switch. It goes on to say it is for only controlling excess hydros when the engine is cold. I guess I should trace some vacuum lines and see if I can verify before shooting my yap off.

 

I have no used parts and boneyards in these parts done crushed all the old Subes. This is a pretty common problem so whats to say the bone yard model would work, yours did, but with how many you have to choose from, I'm sure you picked a decent one. If I thought the reed valves were fixable I'd have at it.

 

I'd like to do away with them both if it would pass emissions with out them.

Pipe plug the exhaust inputs

 

Thanks for the reply.

[Guest Skip]

Paulie Poo, I'll bet you do.

 

Upon further investigation, Qman was correct on my model the AIS functions all the time.

 

There is no vacuum line to the ASV for controlling it's operation, as the underware.man. had said.

Therefore they function anytime there are exhaust pulses.

Will it pass with one side working, the other side plugged???

[Guest GeneralDisorder]

Well - I can't say if yours will pass, but I can say that my 84 wagon passed. At the time it went through, it had NO O2 sensor, a bad Coolant Temperature sensor (what a bitch to locate a new one!), and the ECU light was on solid any time the engine was warm, reporting both of the errors. I insisted that the friend I bought the car from take it through DEQ, here in Portland OR. They will not run a car with any dash lights on, so he crumpled up a used, nasty snot rag, and put it on the dash in front of the light - they wouldn't touch it, so they never saw the light - hehehehe. But it passed not prob. The hydro's allowed by the test were something like 200 ppm, and this EA81 scored 21 ppm, running in open-loop mode. Engine has 146,000 miles on it.....

 

GD

[Guest RallyKeith]

Yo Skip! This is what I would do if I cared enough |I

www.ultimatesubaru.org/Ma...nvalve.htm

 

Reads themselves went in my brat. All I did was plug where those hoses went into air cleaner.

[Guest edrach]

Talk about co-incidences. I just came back from a two day emergency trip to Mountain Home, Idaho to pick up my son's '84 wagon which had this problem and the throttle stick wide open just south of Salt Lake City (he was coming home from Alberquerque). Cost him a carb rebuild from a local shop (ouch). Mike at Smart Service tipped me on the problem when I described the symptoms to him and indicated that the replacement valve is under $20. I'll check with him next week when I pick it up on the necessary modifications. I'll try to post the pictures of the melted pieces and the "screen" mod that the carb shop did to keep out the big pieces of melted plastic. Unfortunately, he didn't plug the hole from the valve which allowed raw exhaust into the engine compartment and subsequently into the passenger compartment. First symptom (weeks ago) was most likely the smell of exhaust with a warmed up engine. My son only drove it 5 miles a day so he wasn't too concerned. It failed big time after about 900 miles of highway driving. Trust me, a new valve is going into my '84 Brat soon (265K+ miles).

[Guest baccaruda]

do EA82s have air suction valves?

[Guest Skip]

Keith, most excellent job on the ASV, we need that put in the USRM if it isn't already.

Thanks for the well done job.

Anybody that has a carbed Sube of our vintage should understand this evil creature.

Stuck throttles are not my form of phun.

My Brat is a bit different in so much that it has two of these creatures lurking under the hood. Each side is independant.but very similiar to yours.

Both are "Chernobles" waiting to happen.

 

Ed, sorry to hear about the prodidgy, my throttle stuck almost wide open coming down a big mountian in central PA in a white out snow storm (gaurd rail looked like a picket fence, passing cars like it made no sense)

 

Interesting note, Honda carbs all come with the screen factory installed, never knew what it was for -until now.

 

Andy, yes if they are carbed, see Keith's link for a scan from the FSM of an EA82 model.

[Guest RallyKeith]

Skip! That's were the link came from.

[Guest edrach]

I finally got around to doing the repair on #2 prodigy's car today. The procedure is exactly as RallyKeith described. I won't bore you guys with my pictures, but this should really go into the archive. I just need to mention to make sure you remember which direction the small reed assembly is installed in. I forgot, wasn't sure which way and had to remove the other ASV to see what was correct (there's that old-timers' syndrome again). The newer ASV costs out at $16.63 plus sales tax at Smart Service (where I get all my parts now that Carter Subaru has dumped the PNWSEC discount ). Apparently the newer cars that use them are vacuum controlled and hence the vacuum fitting at the top of the newer ASV. I just dropped the upper half into my "if I ever need this bin." Just one last question for those who've seen this problem.....Is this an age or milage related failure? Or is it just one of those unlucky failures that happens? I'm debating whether to replace the other side also since there are two ASVs in this '84 wagon.

[Guest SubaruJunkie]

My '83 had one on the drivers side. I removed it cause the engine was louder with it gone. My '84 doesnt have any on it. The '84 is a california car, and the '83 wasn't. Just FYI, sorry i cant help with the situation Skip

 

-Brian

[Guest Skip]

Brian, thanks for the info, the CA car must have had some other EM stuff like the aforementioned carb duty solenoids.

 

Ed, thanks for the info also, any chance on getting the part number for the ASV you bought?

Or is it given in the USRM link?

I feel much better going in armed with a real part number rather than just

"I need the the reed valve assmembly aka air suction valve"

Parts guys don't know our old Subes A TOL.

 

As for you question "Is this a common failure or happen stance?"

Seeings how you, Qman, and I, all have this problem in the time this post has been up here

it gives credit to my original statement. (see opening question)

This subject has been posted many times in the past. Thus the link to the Ulitmate Subaru Repair Manual (USRM)

The reed valve sits in a very harsh environment, similar to an EGR valve. The EGR vavle gets it's very own timer activated dash warning light, wonder why the reed valve doesn't?

As I said and I do believe - "These are Chernobles (meltdowns ed.) waiting to happen."

[Guest kelowna kid]

Different year = different part #, except 76-79 and 81-82

84 is 469907351, not sure about 85 brat

[Guest Skip]

Thanks KK for looking these up, this is an 86 Brat, I appreciate the reply.

 

to quote the link above

 

"One thing I found out when I did this, the hard/easy....was that one Air Suction valve costs $150 and another costs under $20. Ironically the one with more to it costs less. "

 

I would like the part number for the more or less universal model that Ed speaks of I have two Brats both no doubt need these serviced.

 

The question still stands " can the meltdown be averted with some cleaning of the reed valves, " My guess, being spring steel they may just fatigue due to the environ..

[Guest edrach]

Skip, I'll have to dig up the invoice. As soon as I have it, I'll edit this post with the part number.

 

Part number off the box is SPS377200. Odd looking number but Smart Service tells me this is a Subaru number.

[Guest Skip]

Thanks Ed

[Guest edrach]

Skip, as to your earlier comment about the reed valves being spring steel and fatigued: the reed valves themselves are made of some kind of plastic. There are two spring steel "gizmos" which I think limit the amount of travel of the reed valves themselves. I pulled a couple of valves out of a low mileage '84 today just to see what they look like. Both valves were gummed up with exhaust residue; oddly the passenger side was gummed up with oil also. I don't really know what to make of that.

[Guest WAWalker]

As I understand it you can use the reeds from the $20 part to repair the $150 part. Here we don't have emissions testing so I have never tried to fix one, just plugged the holes.

For anyone who cares: The catalytic converter stores & releases O2. In theory, When the exhaust streem is lean the cat stores the extra O2, when rich the stored O2 is released causing the excess hydrocarbons to ignite and burn in the exhaust, thus reducing hydrocarbon emissions. In the newer vehicles with computer controled fuel metering & O2 sensors, the computer provides the extra O2 buy switching the fuel mixture from rich to lean all the time. On the old carbed cars the ASV provide this extra O2 by sucking in outside air between exhaust pulses.

[Guest Skip]

Mr Walker sir, please give a reference as to your statements concerning the cat and it's 02 storage and release function. It does burn the hydrocarbons but.

My understanding of the internal workings are based on it being a "catalyst" and the "storage" of 02 never entered into the equation. It has to come from somewhere. Possibly we are saying the same thing?

BTW some of the older carbed Subarus with 02 sensors, use a set of ECU controlled duty solenoids. These control the rich/lean A/F ratio by controling the air fed to the emulsion tubes in the primary and seconday jets of the carb. This along with along with the ASV system provide the proper ingredients for the cat to catalyze or better said oxidize the unburned hydrocarbons, at least that is what I have read?

 

e.g. from Louis A. Bloomfield, Professor of Physics, The University of Virginia

 

One of the most effective tools for eliminating the unburned hydrocarbons and carbon monoxide is a

catalytic converter. It is essentially a pipe containing a ceramic honeycomb on which there are

countless tiny particles of platinum and palladium. As the unwanted molecules pass through the

honeycomb, they land on the metal particles briefly and are combined with oxygen atoms to form water

vapor and carbon dioxide. The catalytic converter is burning these molecules in a controlled way, with

the precious metal particles acting as catalysts to assist the burning process.

 

 

Ed thanks again for the follow up, I made the assumption from looking at the picts on the link.

Sorry for the misinformation. I will tear into mine and report shortly.

As for the oil found in them, could a condition of serious blow by cause this, were they the vacuum controlled models?

[Guest edrach]

No, mine were not; but the two I pulled at the wrecking yard were.

[Guest Skip]

Ed, yea, I new that I was refering to the ones you found.

Here is what a Chernobled silencer looks like

<img src="http://www.westol.com/neper/silencer.jpg"/>

[Guest edrach]

I can't post photos but I have some interesting shots also. There was also a smaller plastic gizmo with about 5 fittings just above it and I found the bottem of it melted also. Didn't notice it until I did all the work replacing the melted silencer. Thank goodness for Pull a Part. I put the pieces on the counter and they charged me $2 for the whole mess!

[Guest WAWalker]

Skip,

Yes the cat is oxidizing the hydrocarbons. Hydrocarbons (unburned fuel) + O2 + very high temp of cat = burning of hydrocarbons = byproducts of water and CO2. In order for the catslytic converter to oxidize it needs O2 which is cannot produce on its own. So either you need an Air Injection System or computer controled fuel metering. Look at any Legacy. The cat is still doing the same thing to reduce HC but the is no AIS on a Legacy. The cat gets it's O2 on the "lean switch" of the fuel mixture. I was trying to explain the operation in simple terms do to the question of wether you could pass emissions without this system in working order. Tecnicaly, if the cat doesn't have the outside source of O2 it can't reduce HC proficiently. So you may or may not pass emissions, depending on the standard, tune, carb efficancy................Back in the early days of catalytic converters it was thought that the air injection system was the "dilution solution to pollution". Just trying to explain to the non-PhD types that there is a method to the emission madness.