i guess i was a little too optomistic. all i did for the test is an oil change. it's only the 2nd test i've ever had to do on my '85 GSL-SE. do the results show anything obvious to anyone? i have no clue

HC ppm limit:141 result:850!
CO % limit: 0.79 result:2.30
NO ppm limit: 1601 result 51

CURB IDLE even worse

HC ppm limit 300 result: 3507
CO % limit:1.50 result:6.67

i ran the crap out of the car on the highway for 15 min and they did the test right away after that. i'm hoping new cap,rotor,plugs,wires might do the trick and check the timing (though it should be ok) i just don't think i'll have the time to get the cat replaced before the April 1 deadline if that's what the problem is.

 

Did you change your oil, and air filter? my HC were very high one time and I changed the air filter then passed. You may also want to lean out your mixture.

 

yes, i changed the oil last night. i have a K&N filter so i guess i'll give it a recharge too.

 

ok id do a good tune up. newplugs, oil(done), fuel filter, clean the k&n, set the timing. then try to find a good used ACV (air control valve) the acv is the main thing that does smog. if the car drives good and has no ovb. prob. then id swap the acv. this ALWAYS works for me. Mazda's bad idea was puting 1 of the 2 diaphrame right above the exh man. and that is the 1 that gets hard and wont work.

 

I had mine ACV rebuilt last year and passed my emissions with 0.00 HC.

 

God I hope they never do that here **** I aint nothing that would pass

 

my car did amazing on the first test 2 years ago, but i just had a tune-up and installed the new cat (was straight pipe before) since then i've done the oil changes, spark plugs once, and fuel filter about 8 months ago but not much else. i was thinking the results would be a little worse than the 1st one but not that bad !!

 

holy sh#t! i just went out to check the timing (dead on) etc.... I go to check the ACV and guess what.....it's NOT THERE!! There is a plate covering the hole where it is supposed to be. How the #$!! could I pass emissions 2 years ago like that? I imagine it has been that way since i got the header put on. For my last test I just dropped the car off at my old mechanics and said 'make it pass'. i haven't changed a thing since!! of course he only works on race/rally cars now....i hope he's still in the same place so i can see what he did!

 

If he blocked off the ACV your cat is probably toast. The ACV puts fresh air from the air pump to the cats. Without fresh air the cat will not survive. Unless of course you have one of those two way cats that do not requier fresh air. in that case ignore this post.

BTW Do you still have an air pump? The air pump pumps the air directly to the ACV so: no ACV, no use for air pump.

 

yeah, the air pump is just hooked up to where the relief air hose went (under the stock airbox ??) the cat is from Random Technology, from what i remember it is a "three way" or whatever. does the factory manual describe this area better than Haynes? it really sucks.

i'm hoping i can just get another ACV and hook it up somehow. i guess my cat is toast. i'm gonna have to call my old mechanic on monday and see what the hell he did to make this thing pass! man everytime i have some $$$ for mods i gotta fix something just to keep it on the road, i should have a f'n show car by now for what i've spent on this thing!

 

Wow. I've never heard of that high a level of HC's from a Rotary. I've still got my emmisions results from last December, so naturally, I'll post them.

Motor Vehicle Services of New Jersey
Vehicle: Mazda
Model: RX-7
Year: 1985

Nitrous Oxide - Standard(1577), Reading(84)
Hydro-Carbon - Standard(203), Reading(48)
Carbon-Monoxide - Standard(1.15), Reading(0.14)
Carbon-Dioxide - Standard(None), Reading(15.2)
Oxygen - Standard(None), Reading(0.8)

Tested at 1939RPMs

Not bad for sitting for two years. And I didn't have to do anything to it to make it pass. It went right threw, without a problem. That says a lot for American cars - I brought my 1989 Jeep through inspection and it failed for brakes and barely passed emmisions (the person doing the inspection happened to be in a friendly mood)

 

yayarx7.
two way cats? do tell me more. i am about to get a cat pipe made so that i can pass emissions, and that could be a possibility (so that i donot have to hook up my air pump again

 

likely because nobody is stupid enough to go to the test with a burnt out cat, no ACV, and the air pump hooked up to basically nothing.

I wish my old mechanic had bothered to tell me that he did something/paid someone so my car would pass, and that whatever he did, it was 'undone' after the test. but then again he did just finish selling me a new cat, and closed his shop a few months later to work as a race shop only. f#@k it did amazing on the first test.

i still have the original main cat that the first owner took off right after buying the car, would it still be ok? would that be enough to pass (+ ACV + air pump hooked up right) or would i need the two pre-cats as well ? man i don't have time for this. i just started a new job and need my car to get around. my plates expire April 1st.

 

Random technologies makes a two way cat that does not require a fresh air source.

 

Two way cats work without fresh air just GREAT on piston engines.

The first half breaks down oxides of nitrogen (NOx) into nitrogen and oxygen. The second half then uses the released oxygen to reduce (burn) HCs and CO into H2O and CO2.

The problem with that, for a rotary, is rotaries have very low NOx production. (That's why people were flocking to them in the early 70's, before the catalytic converter was invented) Low NOx means no spare oxygen available to convert/reduce/burn the HCs and CO. That's why even the multi-bazillion converter RX-7s in the late 80's and 90's still required an air pump, when 99% of all piston engine cars had done away with air pumps long before.

Interestingly, the new Corvette and the newer Saturn SL's have electric air pumps... emissions standards are really cracking down!

See if you can just put an air pump on, hook the outlet to the converter, and see if it passes. It might. (Maybe) if not, you'll need another new converter, and this time take it back off after the test so you don't burn it out 2 years from now

 

that's why i'd though id be ok to just change the oil and take the test. you'd think the guy who put the cat on for me and took the car to the test would mention that if i didn't take the cat off i would fry it. i just assumed everything was working the way it was supposed to. maybe im not seeing something and i really just need a tune up (wishfull thinking), man yesterday i was out working in a t-shirt it was so warm, today the snow is blowing f'n sideways!

 

Well this is why I keep my orginal setup handy if I ever plan on living somewhere were they test emissions. First removed cat and install header and staight pipe. Remove ACV, highflow airfilter, use air pump to run 6port with a adjustable valve, then have all the orginal stuff handy when you are called to have a emissions test and reintall the stuff and take it off afterwards? Not hard. Not hard at all....This will keep your cat from aging as well, since time and exposure to rotary exhuast ages cats faster then piston cars.

 

i think i'm going to try and replace everything between the header & muffler, get a used ACV, new cat. if everything is hooked up right it should last another 2 years and that will be the last test i have to do. thank god none of the testers know what should be hooked up to a rotary around here, the just look at it, scratch their heads and test it.

 

i thought the acv also went to the exhaust manafold?
if so, how can you correctly hook it up with headers?

 

The ACV goes to the exhaust manifold on 79 and 80 cars, but not the later ones.

 

I had the same problem when I got mine tested about a year and a half ago.

I changed the oil, tuned it up and got it tested
My HC were about 400.
I did everything but change the ACV (didn't know about it then)
I even ran the test w/the OMP disconnected as to not put oil in the system to clean it up a bit. I still couldn't pass so I got the mechanic to add a second cat ($200 conditional pass) and went on... In Sept my test is coming up.

I've had my ACV out of the car and disassembled, and it was broken, so I might grab myself a used one or get a block off plate and run the airpump to the exhaust come test time. Either that or find the right tester If you find a place with a couple of used ACV's let me know.

 

would it be worth hooking up an acv off of a second series to pass emissions. or do you think that the air pump directly to the cats would be enough?