Hello all, I am fairly to this forum, and I sure could use a little advice. I just failed Washington state emissions on a newly acquired 87 turbo. My readings were as follows: in cruise: HC's were 0056 (limit 0220), CO was 00.59 (limit 01.20), and CO + C02 was 15.03 (limit >6.00)I seemed to have passed all the cruise tests. Another story for idle. Those readings were for HC 0852 (limit 0220)failed, CO was 02.11 (limit 01.20)failed, and for CO + C02 was 12.01 (limit >6.00, I passed this)

I do not know a lot about the emission systems. I don't get any error code readings on the car, and I don't really know the condition of the cat. I do get a harsh exhaust smell when I first start it up though.

Any suggestions on where to begin?

 

Idle emissions is generally a function of the ACV on the s4 N/As I am sure that it is the same for S4 turbos also. Thats where I would start. Anyone else?

 

Tune up your car.

 

I payed a ford tech $20 for my emissions! It passed like a 2002 focus

 

I pulled off the relief hose off of the ACV and it was blowing bigtime at idle. My other TII was not doing that so I swwaped them out. It runs, but I can't seem to raise the idle even though the check connector was jumped. I have an older cat (by appearance) but how does one know if it is shot? I disconnected the air tube to the cat and at idle I felt nothing. Should it be injecting air at idle to the cat?

 

I do not belive so, only at higher RPMs should you be injecting air. However there is a way to trick the ACV into doing it at idle which greatly increases your chances of passing. All you have to do is take off the vacuum hose closest to the front of the car and cap it off. Then, drive to the station!.

Rat

 

J-Rat, Thanks, that is the kind of tip/trick I was hoping to get. I actually bought this car for a song, and the previous owner couldn't get it to pass so it just sat most of the time for the last few years. Compression is good, and it runs very smooth, less the toxic fumes it sprays. I changed the plugs, oil, and filters already.

 

If that doesnt do it, Ive got several other tricks you can try. Most of them are a little more involved..

Rat

 

you might just need a new cat.

 

i needed a new cat, heres my results

HC:
Idle: 2890(Limit 220)
Rev: 567(220)
CO%:
Idle: 7.67(1.20)
Rev: 5.56(1.20)
Co2:
Idle: 16.90
Rev: 16.90
02%
.1
1.3
RPM:
Idle: 750
Rev: 2275

End result, new catalytic converter

 

Where do yo get that stuff? I just use alcohol.

Rat

 

this is probably why my inspection sticker on my car says 9/12/01

lol

 

nwaco.......good move on the acv. On a Turbo especially, the *relief* diaphram in the bottom of the acv gets baked by the heat and does not function.

Now about the split air hose that goes to the cat. At idle there won't be any air going there. Thats part of the design. You have to step on the throttle for air to come out of the split air OR, if you wanted to advance your cause, you can take the vac hose on the top of the acv that sticks straight up, OFF. That action will take the vacuum off the switching diaphram in the acv and allow an anemic amount of air to go to the split air pipe that goes to the acv. Another aciton that will get more air to the cat at idle, is to screw the switching solenoid out of the acv body, remove that little plunger, and reinstall the switching solenoid. Switching solenoid being the rear most of the two solenoids that are screwed into the acv body. That allows a little more air to go to the split air pipe to the cat.

EDIT: Fudge. Its the switching diaphram that gets cooked on turbos, not the relief solenoid. Too early in the morning. Disregard that small part of the post, more or less.

Just a P.S. here. The relief diaphram in the N/A cars is vacuum operated but the relief diaphram in the turboii is pressure operated. Just a side note.

I think you really did yourself a lot of good when you switched acv to one that did not blow overboard all the time at idle. That air should have been going thru the checkvalve sandwitched b/t the acv and manifold and then going to the EXAUST PORTs where it mixes with the exaust gas headed for the cat.

Thanks to Six Rotors for what little I know about acv's.

Oh. One more thing if you have a 87. Adjust the variavle resistor to the lean as much as you can and still have a decent idle. Leans out the mixture at idle of course.

 

Thanks all, especially to Hailers for the detailed help. I have tonight to fiddle with it and I am goint to take a run at emissions on Sat morning. I am considering swapping out the cats (it helps to have a few spare cars). I figure it can't hurt. I pulled out the BAC and gave it a good cleaning, changed the plugs, oil, filters. I figure with a different ACV, and a newer cat, I gotta have a better shot. BTW, anyone know where a guy can get another working ACV for a decent price? Or is it possible to rebuild/repair these things?

 

I know of no cheap ones new. If I were you I'd check and see what is not working in yours. The nipple on top that sticks straight up......put a vacuum line on it and suck. It should hold a vacuum. Your pulling a vacuum on a diaphram. No leakage allowed.

On the very bottom, the nipple on the round section.......blow into the nipple and see, by looking into the large exaust hole, if the valve is moving or not.

The first test is for the switching diaphram. The second was for the relief diaphram.

The only way I know to check the anti-afterburn valve is to idle the car, disconnect the air hose coming from the air pump, reving the engine to a high rpm and then snapping the throttle shut. You should feel a suction FROM the acv for a moment. Actually I know another way to see if the antiafterburn is leaking air into the intake manifold. I take the hose b/t the air filter and air pump off. While idling I spray a bit of starter fluind into the airpump. If there is a leak from the antiafterburn to the intake manifold, you'll get a large rise in rpm for a moment. Personally I think you'll get a touch of a rise if its leaking even on a new one. CAn't prove that. Never seen one new. This is another area that can cause a erratic idle i.e. unauthorized air into the intake after the throttle butterflys. My opinion anyway.

That was a good observation on your first post about seeing air dumping at the large relief port and realizing that was not a good thing. Might as well not have a airpump if it just dumps overboard at idle.

While I'm rambling, if you ever find a bad switching diaphram in a Turboii acv, you can find a acv out of a 82-91 rx-7 and if its good, install it into the one on your turbo(the diaphram in the acv, not the acv itself). A touch of metal removal is required. Not much.

 

Again, Thanks all for the tips and advice. I planned on solving the problem before I resorted to desparate moves like the methyl Hydrate, not that I wouldn't, but I like to know what is broken on my cars and how they work. I have learned a lot in just this thread. I decided to swap out the cat with another TII I have. I guess I shouldn't have been suprised to find a hollow cat, completely empty. Go figure. It was more of an echo chamber. Anyway, I have a real cat on it now, and with the working ACV, I figure I have a hell of a shot at it now. It purrs like a kitten now and doesn't stink. I now need an ACV and a cat. Anyone got any spares for sale? Thanks again friends and wish me luck in the government sniff chamber.

 

thank god for FL and no emissions tests. *goes catless*

 

NM straight pipe!

 

what do I do I think I'm screwed, one thing A MECHANIC SAID TO DO IS INSTALL an air pump ana cat and hook the pump directly to the cat but the cat burns up in 200mi, so it's only temporary

 

nwaco, try contacting Ernstborchert4@hotmail.com ... i bought an acv from him for my 91 and it helped me pass emissions.

since my motor was ported, i added a s-afc to help lean out the mixture at lower throttle settings.

good luck,
john