FD3S running super rich/failed emissions
 

Automatic 95 Mazda RX-7
59,xxx miles
Mods:Greddy SP2 exhaust, A-Spec downpipe, Power FC

I need help with my auto fd running super rich and failing emissions. I've had it tested three times and its failed horribly every single time. First time it failed was back in April of last year. After that test I replaced the air filter, spark plugs, and spark plug wires. Took it back in May and failed with the numbers being slightly worst than the first time. After that second time I replaced the fuel filter and sent my injectors to RC Engineering to be cleaned. When I got the injectors back the invoice said one of them was leaking. I thought that might have been the problem so I took it to do emissions again. FAILED with numbers HC GPM 3.2814/1.2000, CO GPM 57.3632/15.0000. Haven't taken it to get tested again but since then have added a new cat, Greddy exhaust, and an A-Spec downpipe. Wasn't going to install the downpipe but the inside of the precat was about to break. Installed the PFC to see if it threw me any sensor codes which it didn't. Still not confident that it'll pass emissions. This past weekend I was about to do a compression test but the tester that I borrowed from O'reillys was leaking air. While it was idling my friend blippled the throttle body and the car shut off. Idle is smooth otherwise.

Sorry for the long post but was trying to give as much information as possible. Any help is appreciated.

do you have a catalytic and air pump on that car?

Yes i do have the cat and the air pump. Im not sure if that would be my problem since my spark plugs are black and I've only driven with them about 100 miles. That was back in August and after that I've just turned it on and let it idle on the weekends.

Attachment 495924

Well you have a Power FC,which says to me that you should be able to tune the car to get to pass.
Also,make sure that the CAT is GOOD.An older Cat may look ok but it can be inadequate as it is not absorbing the fumes it should.
Hit up the Power FC sub-section on this forum and post a thread.That should help you.

1st post listed a "new cat".....but didn't specify brand. Some are better than others.

As stated above, the PFC is tunable. Actually, I would search and/or ask other owners in the Mountain regional section who in your area could tune it. Someone KNOWLEDGABLE with a datalogit could probably help if they were willing. I'm assuming that you're still running the base map that came with it.
And understand that the PFC does not "throw codes". Only the stock ECU throws Check Engine Light codes. The only way you will know if you have a problem on the PFC (other than obvious symtoms) is going to the SENSOR CHECK screen on the Commander and looking at what is shaded.

One thing is to get the car as HOT as possible before E-testing..like a good 20-30 minute run.That is sort of a standard to get the Cat hot and do it's job( Sorry,didn't see new cat).
But JIM (Sarge) has given you a good direction to go in,so obey the Sarge and your car won't get thrown in the Emission's Brig!.

^Obviously I roll through this section when I can, but have the luxury of just addressing the FD stuff. No intention of stepping on a Mod's post. Appologies if it sounded like that. If I had to read through everything, I'm pretty sure I'd miss ALOT more than you guys. :)
At any rate, good point on getting it up to full operating temp before testing. Along those lines, if all else fails, maybe switching back to the stock ECU for testing (fully warmed) might be an option. I've never had to deal with emissions where I live, but have heard others talk about adding 'HEAT" or maybe a little E85 to the regi;ar fuel just until they pass. But again, no personal experience. YRMV

The cat that I installed is an oem cat. All three times that I did emissions was with the original ecu. I would drive the car about 30 minutes on the highway before testing. Just recently installed the Power FC to see if any of the sensors weren't working. Don't know if I want to rely on having to tune the PFC to pass emissions. I was hoping to be able to do it with the stock computer. Another thing that I forgot to mention was that If I let the car sit for too long without starting up it struggles to start up cold. After that I can turn it off and turn it back on without trouble.

Have you checked for vacuum leaks. I had a similar issue a few years ago. I have my AWS line capped at the intake near the throttle body. The cap was cracked and was leaking.

I have checked for vacuum leaks by spraying carb cleaner at them but got nothing. I do have some silicone hoses waiting to go in though so hopefully that helps.

Typically a vacuum leak...even a small one... will manifest itself in a high, often loping idle. Again, no personal experience, but I'm not seeing it effect emissions alot.

Yeah I wouldn't really expect for a vacuum leak to throw my emissions off that bad but i'll probably do them eventually anyways.

I have had injectors that have been "cleaned" before and they still were the cause of my engine problems, this was not on an rx7 but the spray patterns were slightly verry slightly off and caused the issue, not sure if anyone has had this issue but I have had it on another car before, just an idea... anyone feel free to correct me.

I actually did have to send my injectors to them twice because the first time that I got them back one of the injectors wouldn't open up.

Yeah I feel your pain, I had thought that the issue was fixed and then proceeded to move to vacuum lines, catalytic converters, and sensors, wasting a ton of money and then ended up buying new injectors which solved the issue. On the bright side the problem is fixed, with my other car. Hopefully yours will be soon too!

If you're on the PFC Base map that's likely a big part of your problem. They err on the side of safety and come rich. Even if you're not, that would be the first place I'd look. Both for the reason it's rich and as the avenue to pass emissions.
And you never mentioned what cat you installed. They aren't all the same.

Yeah the PFC is on the base map but as I said I haven't tried to do emissions with the the PFC installed. Every single time I've done emissions it has been with the stock ecu. The catalytic converter that I bought is a Mazda cat. I haven't tried emissions since I installed the new cat though. i'll prolly check the IAC valve, ACV, Dashpot, and the TPS this weekend before I take it to do emissions again.

Bro how many you fuel pressure ?stock 38 psi at startup and under load. 32 psi when idling.

Went back to do emissions with the stock ecu, new mazda cat, and made sure that all the air pump parts were working. Also was running half e85 and half 91. I was closer than before but FAILED with HC GPM 1.5471/1.2000, CO GPM 26.6041/15.0000, and NOx GPM passed at 0.8207/2.5000. Car seems to misfire on decelaration so I might look in the FSM for that. Thinking that might be effecting my emissions. I was also failed for not having the precat installed so I'm gonna have to put that back on.

I checked my fuel pressure a while ago and it was within specs according to the FSM but I don't remember exactly what it was.

The Tps how many volt ?

You can check you power fc thottle sensor volt same the manual is ok !

Bro sorry this manual is problem the 3G volt is 0.1 - 0.7

Any resolution to this one? I am starting to get the same problems with my auto car.

- Cold start it runs pig rich, fuels up, nearly fouls its plugs. I baby the throttle til it cleans up, maybe 5 minutes after starting.

- Under load I get misfiring sometimes, but not always. On deceleration I get hesitations and it wants to die.

Stock ECU, stock everything. Checked for vacuum leaks, found some under the UIM, fixed them, but it hasnt resolved.