1984RX7GSLSE

Trying to get 1984 GSL-SE 13B, fuel injected back on the road but it failed Arizona emissions test. I replaced the plugs(NGK), rotor, distributor and wires. What do I do next. Hydrocarbons 3.43, requirment less than 2.4; CO 39.85, requirement less than 20.0. Nitrogen OK 1.47, requirement less than 3.5. Any suggestions? Trying to keep my costs down and hate to put my baby to rest that I've had for 21 years.

Rx-7Doctor

iTrader: (13)

https://www.rx7club.com/1st-generation-specific-1979-1985-18/cal-smog-605555/

steve84GS TII

Your running rich,thats why the CO is high and the NO is low.
Rich running also overloads the cats with extra fuel and leads to high HC's.....which you also have.

Id say you should probably look into the AFM for proper operation,the TPS sensor for correct operation and possibly adjust the variable resistor to the full lean position.Checking this stuff kinda sucks on the older EFI rotaries since Mazda didnt install a check engine light system....(God knows why?)

Do you have static or dyno roller smog tests in AZ?
How does the car run,any quirks or stumbles?
Is the cat old or original....could possibly be clogged/collapsed and causing the engine to choke on its own waste.
How's the power output?

1984RX7GSLSE

They have a dyno, pleanty of power, original cat. Might have to take it in at this point, a little beyond what I can do. I can fix most mechanical, this sounds a little harder. Hope it doesn't cost too much, Got several mechanical problems fixed. Phoenix sure is hard on the rubber and plastic. No rust though. Thanks for the input, you response let me know I probably need some help now.

boyee

iTrader: (3)

what about changing your oil, oil filter and air filter? just to throw this in here.. good luck

p.s. i replaced my cat with a bonez high flow and that did the trick. not sure if they make one for f.i. though

Seniorchief

Bonez does make a replacement cat for the 13b.

laundryhamperman

iTrader: (3)

If you're worried about the cat, you may be able to get away with cleaning it. If the catalyst grid is intact when you look into the cat, this may work, especially if the insides look black or gunky.

With the cat removed from the car, pour into the cat, lemon juice and/or vinegar. I tried this on my brother's subaru, and it resolved a check engine light with a code stating the catalyst efficiency was too low (a code thrown when the O2 sensor behind the cat does not sence a decrease in Oxygen from the Oxygen not bonding with hydrocarbons and CO in the exhaust gasses incomming to the cat). Pour the acids in, and just shake the cat around so that the acid sloshes about and hits everypart of the inside. Wash the cat out when you are done with water so that the acid doesnt' stick around and rust out the converter's metal shell. Re-install and try again.

This won't help you if the rest of your emmissions equipment is not functioning. From what i've read so far, your best bet is to check that your AFR's are not too rich, and to make sure that the air pump and related piping is working and getting air to the cat.

steve84GS TII

Interesting cure,if it works on an OBD/II engine, it cant hurt on a pre-OBD/0 engine.

However,since he says his cat is original,its possible/likely that he has an old pellet type can under there....probably why its no good.These days,its hardly worth it to have the pellets replaced,especially when Bonez rotary specific cats are availible and VERY effective.
At this point,without furthur diagnostics of the EFI,simply replacing the cat might be considered "throwing parts at the problem",and a cat isnt a very cheap part.But Im inclined to think the original cat is probably pooched after 20+ years behind a rotary engine.They arent known to be long lasting and the Bonez cat is such an awesome unit in its own right,itd be considered a performance upgrade even if the old cat were brandnew.If you dont find any other obvious tuning/EFI problems,Id lean heavily towards a new cat.
My 7 year old Bonez is cleaning up a streetported S5 TII engine running about 300HP, and I still pass CA smog standards, with plenty of room to spare.

Rx-7Doctor

iTrader: (13)

First thing I would do is take it to a specialized muffler shop and let them scan the cat for inlet and outlet temps.

1984RX7GSLSE

Thanks for the input, took it in, bad cat. and air pump. I'll play with it a little more, hard to let it go after 21 years. I bouight it right when they came out with the new86 body style, wanted a real RX7!

warwickben

iTrader: (1)

thats sucks u didnt pass, i guess one good thing about liveing in mass is that you dont have to pass emissions if the car is older then 83 and next year any thing older then 94.

steve84GS TII

Just wait,CA standards are sweeping the nation as we speak.Our state suspended the rolling 25 year smog rule a while back precisely for this reason.....
The older cars might make up a smaller and smaller percentage of cars on the road as time goes by,but the amount of pollution they spew per capita, is hundreds,if not thousands of times greater than the ULEV and PZEV vehicles that are being produced these days.

Jason Guthrie

I had the same problem as the original poster and the Bonez replacement fixed it for me, and by a long shot. I'd recommend the cat replacement for anyone that requires a cat. 20+ yo car is about due, ya know?

1984RX7GSLSE

I see an Eastern Catalytic Converter, helps me costs down, anyone have experience with that, I see that it recommends replacing the oxygen sensor too, there is also a front section, what about replacing those too, getting pricey . If I just replace the rear section and air pump, what do you think the chances of passing emmissions are, just looking for an educated guess. I wont complain if you are wrong. What confuses me a little is that there are actually two front sections, anyone know why I don't see two front sections offered. Are they combined on the replacement parts? In my manual I see them marked as No. 1 Pre-monolith converter and No. 2 Pre-monolith converter. They certainly are there physically too, but don't look quite as sectioned off as in the pictures.

Seniorchief

The Bonez converter is a single piece "bolt in replacement" for the two stock cats. It also has the outlet required for connecting the tubing that supplys backpressure to operate your 5th/6th ports. It is well worth the cost in my opinion. If your dealing with getting this car "smogged" I would also suggest replacing the O2 sensor at this time. Good luck.

dread390

if you ask the emission tester he can set the system in manual and run the car on it. it will tell you in real time see what the car is doing and at what RPM it is happening at and it will not send any info to the gov't, if the emissions raise sharply as the RPM's raise then it is the fuel/air blending not the cat and the # look like its the mixture.

Good luck

Wodihor

Pull the break booster line. That should allow more air in your intake. It will cause a vaccume leak but will allow you to get by until you can pull out of the testing center. That is what I did with the 84 to get it passed.

Check out this thread. It might help. I didn't have a cat on my car. So put the cat on, leaned it out and pulled the break booster. Passes emissions.

dellemannia

I spent a year trying to smog my SE. It turned out to be the air contol valve located beneath the water reservoir for the windshield wipers. If it does not hold vacuum then just disable it by plugging the vacuum line between it and the relief solenoid valve.
Thanks to MAZDATRIX!

Rx-7Doctor

iTrader: (13)

The front cats are not a real factor in the emission test. The main cat is the one that does the job and it relys on the air pump and ACV system doing it's job to supply fresh air to raise the temperature in the Cat to incinerate the unburned fuel.

Other major contributors that apply to the SE.

Fuel injector spray pattern and or leakage of the injectors. Best thing to do to clean things up if you are in any doubt of their condition without removing them and sending them out for cleaning. Pick up a Can of BG 44k fuel cleaner. It can be found at better garages and dealerships. Put it in with a 1/4 tank or less of fuel and run until almost empty. There is no other cleaner that is as strong as this product.

Coolant temp sensor in the back of the water pump is the most crucial sensor that the Se has. Alot of times the connector gets corrosion on it and changes the signal to the ECU affecting A/Fuel mixture. Every Se that I buy I get a new sensor for it. Napa sells them for $20-$25.

The O'2 sensor only has an effect in 5th gear on the Se but should be changed every 60k. It will affect your fuel economy.

Given that the complete emission system is working as it should. All tune up components are in good working order. The air filter is clean and the oil is not due for servicing. The cat in good shape the vehicle should pass.

If it does not. The last thing that can be done and it will make it pass is to have a qualified person at a repair shop that has a 5 bar gas anyalyzer. Is to crack the top on the AFM and recalibrate it. But that is to be done as a last resort and whatever you do, don't mess with the A/Fuel located near the passenger shock tower, it just throws more things off.

steve84GS TII

Yea,dont sweat the precats,they are just for cold temperature operation.
They are smaller and closer to the engine so they will light off sooner and start reducing emissions long before the main cat gets going.All smog tests are done with the engine and exhaust system at operating temp,so the precats are moot.
Just be sure they arent falling apart inside or debris can get into the main cat and foul up the whole works.This is a major cause of main cat failure and loss of power.Ive seen very few original rotary pre-cats that were still intact or not totally hollow inside.

All good advise from Doc there,good stuff.

Pulling the vacuum booster hose and causing an artifical lean condition......not heard of that one.....wouldnt really recommend it,even if it does work.Not to mention the smog techs arent likely to allow that when doing the visual portion of the test,unless their your buddies or they are grossly unattentive.

Rx-7Doctor

iTrader: (13)

On the vacuum hose thing also. I believe that the amount of un-metered air going into the system(Past the AFM) would show up on the gas anyalyzer therfore showing invalid testing being done.
What do you think of this Steve?

Also if you created a too lean situationon a FI engine you might wind up with a misfire condition that would raise the Hydrocarbon level.

dellemannia

spent a year trying to smog my SE. It turned out to be the air control valve located beneath the water reservoir for the windshield wipers. If it does not hold vacuum then just disable it by plugging the vacuum line between it and the relief solenoid valve.
Thanks to MAZDATRIX!

OOOPS!

No No my bad.....Vacuum switch not air control valve!

steve84GS TII

Theoretically,a controlled vacuum leak could work.It would be about predictable and controllable as a manual boost controller.....bleh!......but it could work.

I think you hit on the limiting factor though Doc,it would have to be at, or before the threshold of misfiring, or the unburnt fuel would make the pollution numbers worse.

Metered air EFI would go lean with a post AFM air leak.Not only would the leak introduce more air into the intake,it would reduce the airflow through the AFM,causing the door to close and the fuel injection pulsewidth to be reduced.Thats now two seperate events that have made the engine run leaner,and with naturally low NoX output,we rich-run'n rotaries have a lot of wiggle room to go lean before the HC's and NoX trade places, outside of the allowable PPM's.

I actually have pesonal experience making rotaries pass smog by going lean,when all other smog control devices are working and nothing else can do the trick.
A co-workers S4 TII just couldnt get below 200PPM on the HC,even though everything was working as best as he could afford and the car ran great.Max HC allowable was 175PPM,so it wasnt a gross polluter and all other numbers were in range.He was tired of failing smog tests and paying out 65 bucks each time and I didnt really wanna dig too deep into a car I was unfamiliar with.
With no other mods or tricks,I just swapped in a pair of 460cc injectors from an N/A into his primary positions and he went in and passed easily in the 70PPM range.The car still ran fine,although I advised him not to boost up with the smaller primary injectors.......Im saving this little trick for my car in case one day the cat gets tired and my streetport S5 TII engine cant get by the ever-tighter CA standards.

1984RX7GSLSE

Well it's many months later and I was back working this as I had to give back a temp car I had. Got a direct fit Magnaflow converter, but it turned out to be for a turbo, had a welder seal off the front airline and modify the rear a bit. Took it in today and it passed emissions! Thanks for all the help. I also replace the oxygen sensor based on suggestions here. The air pump was OK. Developed a gas leak at the pulsation damper, replaced that with a banjo bolt as suggested on a post (I know the controversy, but I did it anyway), working great. I also had a blinker problem, replaced the hazard switch based on another post and it worked! I love this site, probably would not have it back on the road without everyones help here!