I just picked up a 1985 GSL-SE with just over 100K on it. Last weekend I took it to the wonderful DC emission testing station and failed the HC PPM test big time.

So here is my question, the main CAT on the car appears to be original, but the rest of the exhaust seems to be a Midas special. Without an ODBII connection is there any way to tell what is going on with the car? Is it just hit or miss with replacing different items until it passes? If I replace the main CAT any recommendations on a upgraded one?

Any advice would be greatly appreciated..

Thanks,
Ed

 

I failed emissions big time so here's what I did to pass my -SE:

Since your HC readings are high i'm thinking that your ACV isnt working (on our cars usually its one of the first things to go)

First of all I got a generic cat to replace the main converter because it was dead anyways - you might not have to do this depending on your condition
Then I took some heater hose and re-routed the air pump STRAIGHT into the cat, effectively bypassing the ACV.
Next I did a full tune up (spark plugs/wires, all filters, dizzy cap/rotor)
And right before the emissions test I put in what I *think* was about a 1:3 mix of methyl hydrate:gas (gas gauge not working)

And I passed by a LONG shot

 

Any thoughts on a good aftermarket highflow cat? This one looks like the original.. I may as well replace it while I do everything else...

 

From one SE owner to another, do yourself a favor and do the routine maintenance before you go to far into replacing the expensive cats.

A tune-up for an SE should include the following, and is easily performed in a few hours of free time on the weekend:

1) Spark plugs - get NGK BR7EQ14's or the heat range for your climate. Having fouled plugs will really screw up emissions and cause your car to read poorly, and also perform poorly on the street. Leading (bottom) plugs should be clean and slightly brown when removed, trailing (top) plugs may be blacker and have more crud. Replace with new.

2) Air filter - on the SE, the filter location allows for anything going up the front radiator hole to be sucked into the air cleaner and held. Replacement with K&N for $50 ensures that you get good flow, and the 1 Million Mile warranty doesn't hurt, either.

3) Cap and rotor - replace these with new parts ($14 at BAP) to ensure that you're getting maximum spark to those new plugs. New plug wires are nice to have, but if yours are only a year old or two, not really necessary unless damaged.

4) Do not fill up with premium fuels - the rotary engine will run better and with fewer emissions unburned if you use low grade fuels. While against popular belief, rotary engines have a very short burn cycle, which, when combined with high octane fuels, can lead to unburned fuel residue being expelled into your exhaust to be burned by the cats - increasing emissions.

5) Change your oil - oil gets injected into the intake with each pulse of the oil-pump. Clean oil burns better than old, black oil - reducing emissions.

6) When you go to test, turn off A/C, turn off any electrical items, and run up and down the freeway before you get into line - this will ensure that you're not putting additional load on the engine during testing, and also to ensure that the cats will be good and hot when you pull up to test.

With these simple tips, you should have no problems passing - and that's without spending $300 on new cats that may not even fix the problem. HTH,

 

Ok, ill give this a try... I am going to check the ACV as well... Thanks for the info, ill let you know how it turns out this weekend. Hopefully the storm won't close the inspection station!

I was running high octane gas when I went through inspection, sounds like that did more damage then good. I have an air-filter on the way and the rest I can pick up from a local shop..

Thanks again,
Ed

 

Yeah.. ACV can be the main culprit. Replacing a worn/defective ACV can yield great results. Only drawback is that it COSTS an arm and a leg brand new ~$300. Try borrowing a working one from a friend. = )

 

Ok, here is something interesting... I go to the local Mazda dealer and they are telling me that I nee BR9EQ-14 at $11 dollars a pop...

Seems a bit much is this right?


Did however pick up the rotor/cap also a bit pricey, but should get the job done..

EEd

 

Local BAP has them for about $6 each, but this is for a 'good customer' discount, as I buy a lot of parts from them. You really need to get these plugs, however, since they will have the biggest single impact to your cars performance and ability to pass emissions inspection.

Without new plugs, the rest of the work that you're doing isn't going to be nearly as effective.

New cap and rotor will work very well, but for what they're asking, check around at your local auto-parts houses, but don't take substitutes - they either have the right ones or they don't. The fear with using non-spec plugs is that they can be too long in the plug housings, causing enough of the plug to protrude and get whacked by your apex seals as they go past (leading only, trailing has a pinhole, not straight through). Also, most aftermarket plugs sold 'for rotary' are only of the center post or single-electrode variety. In a rotary engine, the leading plugs fire once per combustion cycle, but the trailing (top) plugs fire twice for each combustion chamber (they fire for the second time simultaneous to the opposite chamber leading, IIRC). Single-electrode plugs put all of this firing on the one electrode, causing fast erosion of the metal, and loss of performance in a very short period of time.

Multiple electrode plugs, like the NGK's designed for your RX7 are designed to be fired much more frequently than piston plugs, and the additional electrodes ensure that as one wears down, the electicity will flow to the next offering less resistance - and ensuring long-lasting performance.

Though they may be expensive, don't skimp on this important piece of the rotary equation. HTH,

 

I found them online place yesterday, they should be here on Monday along with new wires.. I figure ill get it all put together first part of next week...

Thanks for the advice..
Ed

 

Well, I did new cap/rotor, wires, plugs, bonze air intake, lower octane fuel and I still didn't pass. It appears to be running rich.

Does this sound more like a ACV or cat? The cat looks like the original.

Thanks,
Ed

 

check the acv, if its good you prolly need a cat, if the acv is bad you need to fix that first

mike

 

I went on NGK's website and they recommended those plugs for my '85 GSL-SE, too. I bought a set and put them in my car with a set of new wires and it runs great.

 

Here is a dumb question... How do I check the ACV other then replacing it?

The car runs great, lots of power... Just too many emissions...

Ed

 

Yeah, I just flunked the CA test this morning: hi HC and CO at 25mph and 50mph. I just put in new plugs, too.

So I'm thinking of the ACV bypass, which I'd like to do inside an old ACV so it passes the visual check.

B

 

They don't do a visual here... Has anyone written up how to do this?

Ed

 

new Air Control Valve and a new dynomax super CAT did it for me... also new ignition coils... MSD blaster coils preferrably... new oxygen sensors, wires, oil, cap and rotor, check air flow meter, check fuel pressure.... make sure variable resistor is set to lean... TPS is set right and working... YOU'LL PASS GURANTEE YOU... DO AND CHANGE EVERYTHING I JUST MENTIONED AND YOU'LL PASS... if NOT check your ECU... and change it...