Yet another passing emmissions thread, Just BARELY failed.
 

Ok, so after 2 months of work i have finally got my RX7 driveable and to the point of getting it inspected. Just a few minor things left and it will be driveable!

So today i went to the shop to have them inspect it, frankly i was expecting to fail but hoping for the best.

Turns out it did quite a bit better then i thought it would, passed everything except the low RPM HC. And that was only a little off.

Here are the numbers:

High-speed test:

Test - My cars score - Limit

HC - 156 - 174
CO - 0.09 - 1.12
NOX - 14.29 - over 6.0 (aka pass)

Low-Speed Test

HC - 223 - 180
CO - .42 - 1.01
NOX - 14.42 - over 6.0

So as you can see everything was well within the limits except the HC. It passed on the high-speed test just not eh low-speed.

I was already using the Aclahol trick, which is most likley why i did as good as i did. I have 2.5 big bottle of 70% in 2/3 full tank of gas.

Tested everything i could on the car, the airpump works, I just don't know when. vacume lines are all correct (checked via hailers post in another thread).

I am thinking that if i could just lean out the mixture a little i would pass, that resister that adjusts the mixture only works at idle right? or all the time?

My atmospheric pressure sensor is not hooked up which would cause a slightly rich mixture. But i was looking at it today and found there is not even a plug to plug into it?!?!? where does it plug into?

So, anyone have any good ideas? it looks like the car has a semi fresh cat on it, the PO looks to have replaced it when he inspected it last (about 3 years ago but only a few miles). and it is taking care of the NOX fine.

Ideas?

https://www.rx7club.com/showthread.p...06#post5131106

LEARN 2 SEARCH! lol, jk i hate when people tell you to do that cuz when i search something it takes me 1/2 an hour to find what im looking for cuz every post that comes up are people telling other people to search.

Is this a turbo car?

Lean the Car out..Tune it to as Lean as you can get it..

Turbo or non turbo

Probably Turbo. , It seems just a new main cat would get you through.

You might check out the ACV to see if it works on the turbo engine. Pretty easy. On the ACV you have a vacuum hose that sticks straight up. Its from the Switching solenoid. Should have vacuum on it at idle.

Well pull the LARGE hose off the side of the ACV, and with a fully hot engine at idle, pull that vacuum line off that sticks straight up. When you do, put your finger over that hose but also feel the air coming out the LARGE nipple where the LARGE hose on the ACV was connected. When you pulled the small vacuum hose off, the amount of air coming out the LARGE hose metal nipple, should increase dramaticlly.

What does yours do?

I've always wondered how the emissions would go if you put E-85 in it. No E-85 around the DFW area that I know of.

I don't see any way you can lean the engine out more, since the cars on a threadmill, in gear and going fifteen miles per hour.

Everytime I've used alcohol to pass emissions(which i did last week and passed with a blown motor hahaha) I've had less than a quarter tank of gas and put in 16oz of alcohol. I've never had a problem passing like that. You have a lot more gas in there and a lot more alcohol, which is pretty dangerous if you ask me. Because once I pass I go straight to the gas station and fill up the tank to dilute the alcohol. That way I don't risk running the car too lean.

If all else fails, pull an injector, lol.

LOL, i did see that and did search and did everything i could until i got so confused i just made a new thread.

NA, guess i need to put that in the sig.

I think leaning it out would help as well, though how do you do that with a stock car?

It is actually an NA.

I read where you said to do the ACV hose in another thread and tried it eariler. Worked fine, had air coming out of the port when the noid was disconnected and no air when it was connected.

So there is no way to lean the car out? That mixture resister doesn't work above idle?

Yeah, i added more alcohol to counter that i had more gas. I was going to fill up right after but since i didn't pass that would just cause problems. I ain't driving anyplace other than the shop though until it gets inspected.

Yes, variable resistor is only for idle.

Your 02 sensor working? Seems it probably is since you passed one *driving* test. You might check it out though. Back probe pin 2D on the ECU and see if the voltage is there or not. Usually something like 0.65 to 0.85vdc at idle. Hot engine. Memory here.

Or you can check it out to see if it goes in closed loop. YOu put a LED in the two middle sockets of the green, six socket connector. Positive LED wire in the black/white of the two mentioned.

Then, with a HOT engine, you pull the TPS plug off, then put the car in say fourth gear or any gear but neutral or reverse. So now your idling with the lever in a gear and TPS disconnected. Now you slowly rev the engine to over 1500-1700 rpm. The LED should start to go on/off around 1700rpm and above IF the 02 sensor is inputting to the ECU and the ECU is going into closed loop mode. The FSM states the amount of flashes somewhere in the beginning of the FUEL AND EMISSIONS section. EXcept they are using a code detector of some sort. Not required if you follow the words above.

But, it seems yous is working from passing the 25mph test. I could be wrong.

The O2 sensor is new and as you said since it passed the high speed test i am pretty sure it is working. But if all else fails i will pull up my carpet again and see.

I thought closed loop was for non-WOT driving, and open-loop was for WOT? I could easily be wrong that is just what i had thought.

But i already have some LED's made up so i will go test that. I really want to know where the plug to the Atmospheric pressure sensor is, if it was plugged it that would lean the car out a little bit, but i can't for the life of me find a plug to put in it.

So there is no way to adjust the mixture on these cars? even temporarily?

At idle there is a little variable resistor bolted to the passenger strut tower right next to the pressure sensor. This adjusts your mixture at idle slightly, and turning it clockwise IIRC leans it out a little bit (although I'm not certain about the direction) This MAY be just enough. You could prob also run the hose from the air pump directly to the one from the cat, although the extra cold air flow at idle may make the cat go out, so this may not be the best.

Let's recap things. IN TEXAS they do a test at FIFTEEN MILES PER HOUR and another at 25 MILES PER HOUR.

Neither of those figures is at IDLE. The variable resistor only effects....................idle speed. In other words any thing below 1100 rpm for sure. Neither the 15 MPH nor the 25 MPH occur below 1100 rpm.

See the attached jpg for a Texas printout of a emissions test. See the rpm vs speed.

Is that image from an Rx7? Wow if so.

So anymore ideas? I just need that little edge.

Ok, so following what it says in the FAQ, i have been planning on changing the oil here pretty quick anyways (just wanted to make sure it was running and had got most of the old junk in there cleaned out first).

If i was to change my oil and plugs (both of which were changed when i first started working on the car but i have since had a lot of flooding issues and i am sure both are a little dirty) would that really help any?

So no more suggestions?

I have got this this to pass so i can clear out the driveway (and so i can drive it). i have got an MR2 coming anydday now that is going to need that spot in the driveway.

From reasearch and from what i know, high HC means that it is running rich, which is no surprise at all. But in theroy i just need to lean it out some and the HC willcome down, the NOx will go up some but i was so low i have some room to play with.

So thinking about this, i am thinking that I might be able to get away with a little more Alcohol in the tank. As that artifically leans out the mixture, and by the test even with what i have in the tank i am still running lean.

Or another idea i had, is a trick i have seen used before to lean cars out for emmissions. Is to clamp the rubber fuel line down some, so the gas doesn't flow as well. Thus casuing the car to lean out, the problem is it is a fine balacing act with that.

So ANY ideas to get this car to pass? Anything else i can test or that would cause this to not pass?

we had a recent thread regarding emissions, guy who thought his year-old cat was good, bought another one, and voila, passed emissions.

ive seen some older cats like a richer mixture not a leaner one.

since you're so close to passing, it might if you just got it really hot

i googled it, and read a bunch of stuff, and didnt come up with anything definitive.

Yeah i read that, but i am pretty sure his problem was NOx and not HC (the cat mainly gets rid of NOx, HC it only does a little for). I have thought about getting another CAT put on for emmisions and then using a test pipe the rest of the year.

I tried to get it as hot as possible before the test but it takes so long for the actual test to start it is near impossible to get it hot enough.

But i think the CAT is working fine, as the NOx is almost nothing, and that is what it mainly cleans out.

Ah! My veracity is being challanged! I couldn't find that particular Certificate Number (see bottom of the jpg in the other post for the number), but I'm attaching Passing Certificates of my three sorry ass RX-7 over several years.

I'd have thrown in one of my sorry ass Windstar, but it's OBD and not worth looking at.

WOW, those are some great numbers on those, how in the world do you get those cars to do that!?!?!

I just wish mine would pass at all.

Have you tried retarding your timing slightly. You look pretty close to the limit.. that will bring your HC #'s down the only adverse effect is your Co #'s will go up a bit... Looks like you have some room to play with there.
Hook up your pressure sensor! T off a vacuum line

Interesting, i have never heard of this actually. So retarding the timing brings the HC down? My timing was actually never set, i just lined it up best i could with picture on these boards. It could be advaced some already. about how much should i turn the CAS do you think?

This just might do it, i do have room to play with in all the other numbers, just the HC that got me and i was pretty close on that. THANKS!

As for the boost sensor, it is hooked up and working fine (i assume anyways), it is the atmosphic pressure sensor that is in the car by the ECU that is not hooked up. It tells the car how far above sea level it is.

The ATP, atmospheric pressure sensor in the passengers foot well...........you don't have it connected with the electrical plug?????? It defaults to sea level if not connected up. Makes it a bit richer than whatever altitude your presently at. Maybe you meant that it has no vacuum hose going to it because it gets no vacuum hose in the first place.

I'd buy a timing light. Cheap timing lights will do. Twenty to thirty bucks.

LOL, you JUST saw that i didn't have that connected? I have said it just about every post in this thread. You are getting slow in your old age.

Yes, it is not connected with an elerical plug. The reason being this: I bought the car with it disconnected, i pulled the carpet back the other day to look at it and found it was disconnected, but when i tried to find a plug to plug into it, there is no a plug to be found!

So i looked in my parts car for a plu, and it also had the ATP disconnected in it as well with no plug in sight. And it is ripped all apart so i can see everything, no plug for it at all.

I have known all along this would lean me out a little, I just can't for the life of me find a connector to plug into it.

Any idea where it connects to?

My car did have the computer pulled out when i got it and i replaced the engine harness if this maes any differnce.

I PASSED!

So today i went out and changed the oil, it was NASTY, i had changed it with Pensoil when i first got the car but it was REALLY nasty after virtually no miles and just idling. Wow.

I put in some AMSoil 5w-40 (what was recomended by amsoil for my tempreture). Seemed to help it run a little smoother.

I then replaced the spark plugs, the old ones were also a little dirty from the oil i put in the rotors when it was flooding.

Then i retarded the timing about a 1/4 turn of the CAS. went to test it again and it passed with very good numbers actually. thanks Andrew for that tip!

So if your HC is too high, retard your timing and it WILL bring it down.