Emissions Failed. Suggestions?

[PhxVigo]

I took my new (old) Subie in to be emissions tested today, but she failed... They did a dyno test and she got:

 

Hydrocarbons HC, 1.08 G/Mile (Max 1.60, Pass)

Carbon Monoxide CO, 49.55 G/Mile (Max 15.00, Fail)

Oxides of Nitrogen NOX, 0.28 G/Mile (Max 2.50, Pass)

 

"Gas Cap", "Pressure", and "Evap Components" tests also passed...

 

She's an '87 GL wagon, with a carb, 167k miles. Before I bought her, she sat for about a year, but before that she did pass emissions. I have the emissions results from Feb, 2006, back then she scored HC 0.49, CO 5.36, NOX 1.55. I haven't done anything to her other than changing/toping off fluids.

 

Ideas, suggestions? I guess I have a project for the three day weekend now!

 

Thanks!

-Bill

[misledxcracker]

Bring 'er on out to Mohave County...

[zstalker]

how many miles have you put on it since it sat for a year? sitting for long periods of time can have large effects on passing emissions...get some fresh gas in it, drive the crap out of it and see if that helps....couldn't hurt.

~ERik~

[Spiffy]

a quick google search turned up this: http://www.aa1car.com/library/2000/ic60032.htm

 

"High carbon monoxide (CO) emissions are a telltale sign of a rich fuel mixture. On older carbureted vehicles, fuel-saturated plastic floats, incorrect float settings, leaky power valves and misadjusted chokes are often responsible for the rich mixture. On newer vehicles with feedback fuel controls and fuel injection, leaky injectors, excessive fuel pressure and sluggish or contaminated O2 sensors are all possibilities to investigate."

 

so as zstalker suggested there's probably some gunk built up in there that needs to be worked out... you may be able to run some fuel system cleaner through there... and always make sure the car is fully warmed up when you have it tested...

 

 

--Spiffy

[Robert M]

I think Spiffy's right. Complete tune-up, lean out the mixture, and make sure you take it on a 20-mile zoom down the freeway before you pull into the emissions station next time...

[PhxVigo]

Thanks for the replies. I had about 20-30 miles on her since she had been sitting. It was still the old gas in the tank, so that probably didn't help much.

 

I took Spiffy and zstalkers advice and put some miles on her today. The gas was near empty, so I put in 13 galons of gas and some fuel system cleaner stuff. I drove all over the place and then some... Total of about 380 miles. I have no idea if it will help, but it was sure fun... I didn't get anywhere very fast, but she ran like a champ and never missed a beat. It looks like I got about 29mpg, mostly highway miles.

 

The article Spiffy linked to mentioned a misadjusted choke... I don't think mine works. It seems to be stuck open. I have to give the car some gas to keep the RPMs up around 1000 for the first couple minutes. After that she idles on her own. I popped off the air cleaner cover this morning, and what I believe is the choke is fully open. It should be mostly closed when the car is cold, correct?

 

Tomorrow I'll pull the plugs and see how they look. Althought I don't really know what I'm looking for... Maybe I'll post a picture or something...

 

Thanks!

-Bill

[TomRhere]

The linkage on the carb keeps the choke from closing until you hit the go pedal, then it should close, cold engine of course. GD has mentioned many times that the spring coil for the choke likes to break the tab end off, so if the choke plate doesn't close on it's own, chances are that the spring has broke. Move the choke plate by hand to see if there's any binding of the linkage, as that will effect operation.

 

As far as looking at the sparkplugs, they should have a Light Tan color to the center ceramic, may be Pinkish looking from some gas additives. Anything else indicates a problem of some sort, depending on condition of plug(s).

[PhxVigo]

I pulled the plugs... They have a gray-ish color with some black around the edges:

Plugs 1

Plugs 2

 

Also, I found a couple hoses that don't seem to go anywhere...

The first connects to the air cleaner box on the drivers side. It has a short section of hose that runs down near the sparkplug area. I couldn't find anything down there that it might connect to:

Hose from aircleaner

 

The other is down by the bottom of the engine on the passenger side. It's a short green hose maybe 4 inches long with hose clamps on each side. There is a hardline that comes out right next to it:

Unknown Hose

 

I checked the choke per TomRhere. With the engine cold, I pushed the pedal, nothing moved. Tried pumping the pedal, still nothing. I moved it by hand... It was a bit stiff when I first moved it, but it moves freely now. It doesn't close all the way, fully closed seems to leave about 3/16th of an inch from the plate to the side of the housing. Also, there is no "springyness" to it. Perhaps the spring is disconnected/broke. As long as it's open though, that should not effect emissions, correct?

 

Thanks again for all your help!

-Bill

[GeneralDisorder]

It has a short section of hose that runs down near the sparkplug area. I couldn't find anything down there that it might connect to:

Hose from aircleaner

 

It's not supposed to connect to anything. Leave it.

 

The other is down by the bottom of the engine on the passenger side. It's a short green hose maybe 4 inches long with hose clamps on each side. There is a hardline that comes out right next to it:

Unknown Hose

 

No clue - power steering, AC, or automatic transmission related. It's not stock with that color hose and those clamps. Maybe a transmission cooler?

 

I checked the choke per TomRhere. With the engine cold, I pushed the pedal, nothing moved. Tried pumping the pedal, still nothing. I moved it by hand... It was a bit stiff when I first moved it, but it moves freely now. It doesn't close all the way, fully closed seems to leave about 3/16th of an inch from the plate to the side of the housing. Also, there is no "springyness" to it. Perhaps the spring is disconnected/broke. As long as it's open though, that should not effect emissions, correct?

 

Should be open when hot, and closed when cold. But that's a basic description - there's more to them than just open and close. Rate of opening, accelerator pull-off, ect.

 

GD

[TomRhere]

The Green hose is someones "quick-fix". There should be a formed hose on there, up to the Black Silencer just above the Air Suction Valve that the Greeen hose is on. The Silencer in the pic is broke where the hose should connect.

 

I may have those parts out in the garage, I'll look after work. Yours if you can't find any closer.

 

You really should run NGK plugs, Subarus don't always like other brands, and tend to run funcky on them.

[PhxVigo]

Well, I took her in this morning to see if my efforts paid off... Results; Failure.

 

HC 1.14 (Max 1.60, Pass)

CO 21.46 (Max 15.00, Fail)

NOX 1.16 (Max 2.50, Pass)

 

There was a huge improvement in CO, but I'm still about 7 grams/mile from passing. Also, the NOX was a bit higher. Still passing, but like 4 times higher than the original test.

 

I drove her for a little over 30 miles, and then straight to the testing place. She should have been good and warmed up.

 

In addition to what I've already posted, I replaced the plugs with NGK brand last night. It made a huge improvement in driveability. It also seemed to raise the idle a little bit. The idle kind of wonders around a 400 RPM range. It used to be in the 500-900 range, but it's more like 800-1200 now.

 

I did some fiddleing with the choke last night, it seems to be working much better. I can start up and drive off now, no waiting for it to warm up. I do need to verify when I get home that it's properly opening all the way. It was last night, but it's one thing that comes to mind that my be causing me to run too rich...

 

Any other ideas, suggestions?

 

-Bill

[PhxVigo]

I worked late last night, so didn't have a chance to fiddle with the car. I did pop off the air cleaner cover after the drive home and confirmed that the choke had opened all the way.

 

If it's running too rich, then I've either got too much fuel, or not enough air. I'm trying to think of things that might cause that...

 

The article Spiffy linked to mentioned leaky power valves... I'm guessing that's some bit in the carb that squirts fuel. Is there any way to check that it's not leaking?

 

What if the little flapper bit in the secondary barrel was not opening? Any way to check it?

 

I also poked around the emission testing website and found that I could download the trace from my last attempt. It's all greek to me, but I'll post it for your viewing pleasure.

Emissions Trace

 

-Bill

[Gloyale]

The first connects to the air cleaner box on the drivers side. It has a short section of hose that runs down near the sparkplug area. I couldn't find anything down there that it might connect to:

Hose from aircleaner

 

GD was somewhat correct, there is a hose that should just hang loose in that area. however that isn't it. I have a feeling the 2 hoses are switched.

 

The removed hose in the picture is the breather hose for the Drivers side valve cover. You can see how it is flared slightly at the end and has marks from having a clamp on it. That hose should go from the open port on the air cleaner in the picture down to the valve cover.

 

The hose that comes out of the air cleaner just forward of that one, same size, is the one that should be pointing down at the engine just hanging.

 

The other is down by the bottom of the engine on the passenger side. It's a short green hose maybe 4 inches long with hose clamps on each side. There is a hardline that comes out right next to it:

Unknown Hose

 

Is this car 2wd or a California model? If so, that is part of the Air Suction Vavle/Anti afterburn system. It should run back under the car and hook into the port on the side of the Catalyst. It would have been a black hose from factory. It's probable that you're cat was replaced with a generic without the correct port. If that is the case then that green hose should be capped.

 

If it's not a 2wd or Cali car then someone has swapped in an engine from one. If that was the case you'd need to make sure you don't stil have the *feedback* carb on there running without an ECU. That could throw Emissions off for sure.

 

 

Just as general pass emmisions advice for an old carbed Subaru; I would spray a bunch of lubricant down into the bottom area of you're distriutor. Often the Mechanical advance weights get sticky and throw off the timing under laod.

[PhxVigo]

Is this car 2wd or a California model?

 

It's a 4wd dual range with 5 speed manual. Don't know how to tell if it was a California car. I have never seen an "ECS" light on the dash (I believe that was one of the things to look for.) From an old parking sticker, I know it spent some time in Minnesota, but don't know if it was sold there or migrated.

 

If it's not a 2wd or Cali car then someone has swapped in an engine from one. If that was the case you'd need to make sure you don't stil have the *feedback* carb on there running without an ECU. That could throw Emissions off for sure.

 

What would I look for to tell me if it's a transplanted feedback carb?

[Gloyale]

It's a 4wd dual range with 5 speed manual. Don't know how to tell if it was a California car. I have never seen an "ECS" light on the dash (I believe that was one of the things to look for.) From an old parking sticker, I know it spent some time in Minnesota, but don't know if it was sold there or migrated.

 

 

 

What would I look for to tell me if it's a transplanted feedback carb?

 

Look for 2 duty solenoids mounted to the mainifold. Passenger side, near the thermostat housing.

 

Take the aircleaner off, and take some good pics of the engine.

 

Also take a pic of the area in front of the passenger side strut.

 

Post those pics and we can tell you what's what.

 

 

Funny though that the car would pass previously with that engine. Has it ever been swapped.

[Zebisko]

What appears to happen is that when the car is put under a farely heavy load, it doesn't completely burn its fuel. When it is low load, everything is fine. If you notice in the second and third graphs, the HCs and COs spike under acceleration from 25-50 mph, but when they let off and maintain 50 mph, the numbers drop like a sack of bricks.

 

It could have something to do with the secondary barrel, or the power valve. But what might be another possibility is that your ignition wires, distributor cap, rotor, or coil might be weak. I'd check your cap and rotor before messing with the carburetor.

 

Also, can you get the graph for the other emissions test?

 

I worked late last night, so didn't have a chance to fiddle with the car. I did pop off the air cleaner cover after the drive home and confirmed that the choke had opened all the way.

 

If it's running too rich, then I've either got too much fuel, or not enough air. I'm trying to think of things that might cause that...

 

The article Spiffy linked to mentioned leaky power valves... I'm guessing that's some bit in the carb that squirts fuel. Is there any way to check that it's not leaking?

 

What if the little flapper bit in the secondary barrel was not opening? Any way to check it?

 

I also poked around the emission testing website and found that I could download the trace from my last attempt. It's all greek to me, but I'll post it for your viewing pleasure.

Emissions Trace

 

-Bill

[PhxVigo]

Look for 2 duty solenoids mounted to the mainifold. Passenger side, near the thermostat housing.

 

Take the aircleaner off, and take some good pics of the engine.

 

Also take a pic of the area in front of the passenger side strut.

 

Post those pics and we can tell you what's what.

 

 

Funny though that the car would pass previously with that engine. Has it ever been swapped.

 

I don't believe the engine was swapped since the last time it passed emissions. The previous owner bought it for cheap transportation while he was saving up money for something bigger. He drove it for about a year when it started not idleing right. He bought the new car he wanted and the Subie sat for a year before he decided to get rid of it... Before that, who knows?

 

Pics below. I left them big for max detail...

Engine Bay, Front to Back

Engine Bay, Driver Side

Engine Bay, Pass Side

In Front of Pass Strut

Pass Manifold Area, Front to Back

Pass Manifold Area, Back to Front

 

-Bill

[ShawnW]

Grab a can of carb cleaner and mist around the engine compartment looking to see if the idle increases anywhere that you are spraying it. This will find leaks and things you need to seal or connect hoses to, etc.

 

If you have a timing light please check the timing. If you dont, go to Autozone or similar and rent a timing light. If you dont know how to use it reply back here and we will help. Just dont remove the distributor! Its running right now it just may need a slight tweek.

 

Unfortunately high CO is a pretty vague thing. It can mean so many things but most of all just remember dont get frustrated too badly with failure of emissions. Passing will really make the car run peak and make that car you have aquired for its gas mileage all the more worth it.

[PhxVigo]

Also, can you get the graph for the other emissions test?

 

No. They only save the trace from the latest test. Before that, they just save the g/mile "score".

 

But what might be another possibility is that your ignition wires, distributor cap, rotor, or coil might be weak. I'd check your cap and rotor before messing with the carburetor.

 

The wires look like they are in good shape, there is no tearing around the boots and no corrosion on the metal contacts. They're 7mm, I didn't notice a brand name.

 

As for the rest, I believe I saw some tests in the Chiltons manual you could do with a multi meter to see if they were in working order. I'll try that and see what I come up with...

[PhxVigo]

I found the vacuum host that opened the secondary flapper thingy in the carb. Sucked on it and it popped open no problem.

 

On the distributor, the cap looks fine, the rotor seems like it can move on the shaft more than it should (maybe an 1/8th inch back and forth). There doesn't seem to be any side to side play on the shaft. I sucked on the vacuum advance and it rotated a bit and stayed there until I stopped sucking.

 

I tested the spark plug wire resistance through the cap. The two short wires were about 3k, one long was about 8k and the other was 14k. That's within the limits suggested in the Chiltons manual. Both long wires are pretty close to the same length, but one has quite a bit more resistance. Perhaps this is an issue.

 

I also tested the coil as found here. I came up with 1.6 accross the outer terminals, and 13k from the center to the outer terminals. That is outside the specs listed on that page, but I would think the specs would depend on the particular model of coil, no?

 

In any case, if you guys think there's an issue, it looks like I can get cap, rotor, and plugs for right around $50. The coil would add another $40.

 

Grab a can of carb cleaner and mist around the engine compartment looking to see if the idle increases anywhere that you are spraying it. This will find leaks and things you need to seal or connect hoses to, etc.

 

If you have a timing light please check the timing. If you dont, go to Autozone or similar and rent a timing light.

 

The idle kind of wonders around a 400rpm range. I tred the carb spray thing, but couldn't tell if it was sucking it up, or just wondering... I also borrowed a timing light and it is close... It bounced around 1 degree or so either way from 8 btdc. I now know that I failed to disconnect the vacuum advance when I checked timing before. That may have been why it bounced around, or it may be related to the idle speed changing. I haven't had a chance to recheck the timing properly with the advance disconnected.

 

most of all just remember dont get frustrated too badly with failure of emissions. Passing will really make the car run peak and make that car you have aquired for its gas mileage all the more worth it.

 

Thanks for the encouragement! I'm not frustrated yet... I bought the car to have something to work on and learn about. I figure this is just one step in that process.

 

-Bill

[Gloyale]

I don't believe the engine was swapped since the last time it passed emissions. The previous owner bought it for cheap transportation while he was saving up money for something bigger. He drove it for about a year when it started not idleing right. He bought the new car he wanted and the Subie sat for a year before he decided to get rid of it... Before that, who knows?

-Bill

 

 

Well, what I'm seeing in the pictures are remnants of the Feedback Carb system. The Device mounted to the passenger side strut with 2 vac hoses, and the extra hose out of the reed valve by the passenger exhaust. Both of those things are from the Feedback set-up. There is supposed to be a pressure sensor mounted to that bracket on the strut as well.

 

But the intake and carb appear to be normal Non-feedback setup. So it seems this was a feedback car swapped to non feedback. Which is good.

 

I typed this and then in examining the pictures more it appears that those blue *T* fittings are Subaru, and look like they've been there a while. It doesn't match any of the Carb setups for any year or version I've seen, but I can't say for sure that it's not supposed to be that way. However the 2 hoses from that device I mentioned should not be T-d into the lines like that. Get rid of that. unhook those hoses and chuck them and that device they are hooked to. They are *T*-d into the Slow and Main air bleeds for the carb. Could be a big part of the idle issue. Can you look at the tag under the hood? It should have a small vacuum diagrahm, and some writing. Should say something like "this vehichle conforms to applicable standards for emmissions for all ____ (year) vehicles for sale in ______(Cali or US)" A picture of that tag would be great, to tell us if this car was originally feedback or not. Also look under the steering column, is there a Gold colored 4"x6"x1" box mounted to the bottom of the column?? If so this was a feedback car.

 

edit again. I do not think you have the feedback set-up. The device is the altitude compensator. It should be there. I've never seen one on a non Feedback set-up. The *extra* green hose at eh ASV should make a *U* bend, and connect to the back of the reed valve directly below it. I'd replace it with Emisions hose instead of the heater hose on t now.

 

So, on to tackling the emmisions.

 

I would change you're plugs out with NGK plugs only.

 

Also, using the timing light, you can observe the advance curve of the disty. I had problems passing emissions caused by the mechanical advance weights in the base of the disty being stuck.

 

Hook u the light, disconnect and plug the vac advance.

 

Now rev the engine, and watch the timing advance and then back off and watch it retard. The advance and retard should be smooth and should match the rpms. If the advance takes too long, or the the timing stays advanced even after the RPMs are dropped, then the weights are sticky.

 

Spraying lubricant down into the base might help, but fully disassembling the disty and cleaning and greasing the weights is the best options.