So, my '86 GXL horribly failed emissions at idle. A couple friends of mine are telling me to remove most of my emissions stuff, as they say that they cause more problems in the long run, but I just don't know what to do. If you look at the loaded reading, it passes just fine, but at idle, my car is running about ten times as high as the standard is supposed to be. I'm stumped, clearly my car is running rich, but I don't know what to do. Someone suggested that my cat might be out, and that may be a possibility. My car still has all the emissions stuff, and any info/suggestions would be greatly appreciated.

 

step 1 is to make sure that the PORT AIR portion of the Air Control Valve is working.

the shop manual is @foxed.ca if you need it

 

much appreciated, will get right on it.

 

Dittos from me also. The so called Load passes barely but the idle is ridiculously high.

The ACV on the right side of the engine sends airpump air to the exhaust ports ........which mixes fresh air with the exhaust gasses prior to the catalytic converter. If the ACV isn't working right, then no air goes to the exhaust ports at idle.

The two elect solenoids (are there any other kind?) do nothing in this regard and for right now totally ignore those two solenoids. What controls the ACV on your 86 non turbo, are the two small vacuum lines located just above the ACV. THEY in turn are vacuum sources from the left side of the engine coming from the RELIEF and SWITCHING solenoids............which are in turn controlled by the setting of the TPS.

So with a HOT enigne, pull those two vacuum lines off one at a time and feel to see if you have vacuum on them or not at idle. IF memory serves both those small vacuum lines should have vacuum on them at idle with a hot engine.

The above is not from the FSM's checkouts ............but should give one an idea whether or not the ACV is bad or if the ACV just is not getting a vacuum signal from the two solenoids mentioned earlier.

Another quick check is to pull the LARGE hose off the outboard side of the ACV when the engine is HOT and idling. There might be a whiff of air coming out that large nipple on the side of the ACV, which is normal for a old car, but if you reach over to the other side of the engine and pull the BLUE elect plug off the Relief solenoid, then you should now notice a MUCH larger amout of air coming out that large nipple on the side of the ACV.

Put the blue plug back on the relief solenoid and now rev the engine up to ??? over 2 grand I believe and now once again a large amount of air comes out the side of the ACV.

So how did your car act when checking the above quick checks? We trust all the solenoids and vacuum hoses are still intact on your car and have not been removed.

There is a FSM checkout of the ACV in the FUEL AND EMMISSIONS section of the online FSM.

 

Step one should be: Tell your friends emissions components are there...... to allow you to pass emissions

Then follow the advice hailers and j9fd3s have posted, they are right on as your idle is reading rich....

 

Could be a number of things. When was the last time the fuel injectors were cleaned? Tune up?

 

It's a lack of air pump air going to the exhaust ports at the engine mating point with the exhaust manifold.

During the Load test, the 02 sensor is in the loop and controlling what was a rich mixture at idle, into a mixture of approx 14.7afr while driving. 02 is not in the loop at idle and RX run rich at idle from the factory. Normal.

 

agreed. i've had cars that wont start because the injectors are so bad pass smog with no problem.

the wideband shows my stock S4 around 16-18:1 at idle.

 

First thing to do is : You need new friends. emission stuff does not cause problems in the long run. lack of maintenance does. Plus your friends are stupid enough to ask you to remove all emission equipment when you're trying to pass emission test ? failed.

Second is : like others have said, you need port air to work to pass the idle test. your "running" test barely made it. fix the port air issue first, then see if your CAT is dying.

 

I'm going through the same thing myself but with my FD. I failed emissions horribly recently, and realized that my secondary air injection is not working. The air pump works, but the air isnt making it to the catalytic converter. I suspect my ACV is the problem, but im gonna pressure test the system to be sure.

 

I've heard of a little trick to passing emissions. Run a piece of hose directly from the air pump to the cat. Most garages will know nothing about rotaries, so they probably will not catch it.

 

no it should be going to PORT AIR. on the FD its usually a vacuum line that got switched. second culprit is that the engine got built with the rotor housings swapped F&R, this blocks off the PORT AIR passage, and it'll never pass

 

that doesn't work well enough in CA

 

looked at j-rats formula for cheating emitions?

emitions testing is just a cheat for us however IMO....