J-Rat

iTrader: (2)

My car is still failing emissions like it was cool, and I cant afford to keep going back to the station everytime I think i fixed someting. Its getting really expensive...Does anyone have the O2 idle readings for the 87-88 N/As? All the tech manual says is "below 1V" but I am still failing. My readings right now are .67-.68 V at idle...

Rat

amemiya

I don't know the voltege but it is in the rich when it idles

J-Rat

iTrader: (2)

Now I am looking at .52-.54V at idle...No ecu trouble codes illuminated.

Grizzly

Well my O2 is not even conected and it does'nt have any warning lights. The only thing i noticed is it runs very Rich and lacks power.

I would love to know what voltage my T2 O2 sencer is suposed to put out?

Thanks

J-Rat

iTrader: (2)

I cant seem to figure out why the car is way too rich...So I guess the injectors come out..HAILERS!!! you got any idle O2 readings?!?!?!

Rat

Scott 89t2

do you have the air pump on? if so your ACV might be shot. you should get around .1v with airpump on, and .7 or so with airpump off. (or not working...)

J-Rat

iTrader: (2)

Yeah, air pump is on, and the split air seems to be working. This is the second ACV. I can try a third one...But it seems like I am chasing my tail. So .1v is the idle reading I am looking for? This would save me NUMEROUS trips to the emissions station to see if I fixed anything..

HAILERS

Scott is right on, on this. It should on a functioning acv give about .1 or a minus. Although my car passed emissions just a couple of weeks ago, I noticed that at idle the sucker was reading .6 to .7. I let it idle and went around to the side of the car and took the switching vacuum line off the acv and put a long vacuum line on. Then I sucked on the line. The diaphram was good because I could pull a vacuum and hold it. What I did notice, is that when I was pulling the vaccum, the voltage droped from the .7 down to a minus. I repeated this several times. I came to the conclusion that although the diaphram was good, its getting ridgid and is not as flexible as it should be, so the vacuum pulled by the car is'nt good enough to move the switching valve in the acv.
All that said, didn't you take SixRotors advice and more or less disable the switching part of the acv????????? If all that air is going to the split air and the catalytic converter, and none to the port air, that would explain why you have a reading ofl .5 or whatever. P. S. That turboii I have passed emissions with a busted switching diaphram in the acv, and it always has a reading of .8v after coming to rest. It will like any other car drop way down if I just let it idle for ten minutes. I've taken the turbos swithching diaphram out on two engines that I have and both were hard as a rock and would not hold a vacuum. I'm betting money yu have the switching valve tricked out. Oh, and I also have come to the conclusion that your catalytic converter is shot and you'll not pass emissions till you get a new one. Isn't it just amazing how I know all that from a thousand miles away and never even seen your car. Gotta watch that free advice. humor.

HAILERS

The way I understand it, if the air at idle is passing thru the port air, that port air is prior to the o2 sensor. So your mixing pure clean fresh air in with the exaust gas from the engine, and that should dilute the mixture causing a low reading at the 02. If your switching diaphram in the acv is kaput or tricked out, the fresh air goes to the split air and then intot the catalytic converter. That means that the fresh air bypassed the o2 sensor. Now the 02 sensor is seeing just the exaust gas by itself. Most people that have no air pump or the belt cut or a block off plate where the acv should go, say that they have a o2 reading of .7 or .8. My typing is getting better. I'd rather do it all in caps. Pisses some people off big time. not humor. If I said anything out of place in the above, I invite SixRotors or IRV to step in and correct the misstatement. One S

J-Rat

iTrader: (2)

You are definately right about the CATS being shot...I have come to that conclusion. That accounts for the bad CO readings. It does NOT account for the dismal HC readings. I am running rich, pure and simple. I tried disabling the switching valve so there was air to the cats constantly, I even removed the vac line to my brake booster to lean out the mix even more. Still failed miserably. My idle O2 readings stay steady around .54-.52 V. And I am getting no ECU failures. I unplugged the pressure sensor just to see if the ECU would flag it. It did so right away.

The basis for this thread is to find out if it is possible to see if your emissions are going down by checking O2 voltages. But the point is now moot since I got pissed and started dismantling the top half anyways. I am gonna try to verify the injector part numbers and maybe get them tested. Hell, I may even get a new set! I gotta go to bed, my head is pounding from smelling exhaust all day.

HAILERS, I know you gave them to me before, but do you have the 87 injector part numbers?

RAt

HAILERS

THE ones that end in a -1350 should be the 460cc. If they end in -1370, they should be 550cc for a turbo, and your car is a N/A. I know what your trying to do with looking at the 02 voltage at idle. Your trying to see if its rich and trying to get it down around .4v. I've thought about that and tried it using the variable resistor, and finaly came to the conclusion that the 02 sensor is not accurate at idle. You can drive the car and see the voltage reading and come to a stop and idle. The voltage will show a large figure if the acv or airpump is not quite right, but then if you watch it for a couple of minutes you see the voltage decrease and eventualy drop down to a low figure. But can you trust that figure???? From what I've read the 02 sensor is only accurate in the stoich range. High temp give false readings and I figure low temps do the same. Seems like you'd need one of those wide band 02 sensors to get a accurate reading and they cost a couple of hundred bucks.
Really interested in what type of injectors are in your car.

ralph f cooke

You may not need a wideband O2 sensor, I had read that O2 sensors do not work at low temperatures, I suspect this is why the idle on RX7s is not run closed loop.
Newer cars use a 3 or 4 wire O2 sensor, with a built in heater coil. I fitted a 4 wire to my TII and the mpg has improved from ~14 to 18~20. I guess the old one was giving false readings. Its pretty easy to install, one of the heater wires goes to ground, as does the low side of the output pair, the other heater wire goes to an IGNITION SWITCHED supply and the hot output goes to the original O2 signal wire.

I remember reading somewhere on this forum that someone had succeded in making the idle run in closed loop mode. If this has been done then I would love to know how as I it would fix the problem of running stinking rich when you take off the air pump and ACV.

ralph

J-Rat

iTrader: (2)

Well, I ran the Variable Resistor over to the "L" side. Pretty much till the car barely idled (a trick we use on the V-8s). That still didnt affect the numbers signifigantly. I understand what is being said though, there is no way to accurately use the O2 sensor to check the Idle mix, and it probably wouldnt work is you were tampering wiht the timing to see of you could get a better burn either. Unless you shell out for a wideband or heated O2 sensor. Which I may do in the future but all my $$$ is tied up in just getting this car to run in stock form, which is my ultimate goal. HAILERS, I am getting ready to get the rest of the intake off so I can pull the injectors, I will post as soon as I am done. I dont know how long this could take since its my first time..

Rat

J-Rat

iTrader: (2)

Okay, the injectors are 1350's All the way around. Primaries and secondaries. I dont have a clue as to how to test them, is there a place I can send them to be checked? Or is it better to get new ones?

J-Rat

iTrader: (2)

Also, the injectors all measured 2.0 Ohms on the dot.

J-Rat

iTrader: (2)

Oh..and one more thought. When I was replacing the ACV, there was a diaghram, about the size of a quarter, that was on the motor behind the ACV. It was all rusted and nasty lookin. Is that the one you were referring to earlier?

Rat

HAILERS

That half dollar disk is a check valve. By the way you have jinked me. My wifes 86 insp is two months out of date. Out of curiosity I put a wire tap on pin 2D of the ECU. Reads about .85 to.9v consistently at idle. Ran it on the street. Reads stoich at cruise, and when I let off the throttle it goes momentarily to .001 or so then as idle is reached it goes to .85. OH DARN AND KICK THE CAT AND DOG. I went to my 87. Idle is .001 or so give or take. Full throttle is .75. Let off the throttle and momentarily goes to .00000 or so then as the throttle comes to rest .1 or .01, next to nothing volts. While this 87 is idling I pulled the forward vac hose off the acv. The volts go to .500 or so. Put the hose back on and its .001 or so. With that in mind I went to the 86. At idle .800. Pulled the fwd vac hose off and it STAYED AT .800. I put a vac hose on the nipple and a mittyvac. Still .800. Conclusion: My wifes car has your problem. With one exception, the car does not smell like gas fumes. Its rotten eggs smell we're so familiar with. I'm pulling the intake and going to see if I've got something other than 460s.
If that proves normal, I'm going to swap acv b/t the 86 and 87. By the way, this 86 car has passed emissions witht this rotten egg smell in the past two years. I on the whole leave this car alone as long as it gets the wife to and fro. She has a disability that is getting worse so she only drives to the stop and rob for cigarettes. So this problem could have existed for sometime now and I was not aware of it.
My air pump is a pumpin. The relief valve works. The switching diaphram is good. I'm a bit puzzled.
Last thought. That disk that was rusted up. There is a checkout for that in the manual. Gotta go. Gotta pull that intake off and its hot right
now. edit: Just took a last look at your last post. No, the diaphram is inside the acv. If you put a hose on the fwd nipple right above the acv and suck on it , it should hold a vacuum. I USED to consider that a sign that the diaphram was good. I'm in doubt now. gotta go pull.......

HAILERS

Back. I pulled the intake. It has the 19550-1350's in it. Should be 460S as in stock. I cleaned and flow tested about 10 injectors last week and I think I'll put those in and see what happens. Don't expect much. Might put another acv in before. Gotta think about that. Easier to do withe the intake off. Can't believ my acv is bad. Both diaphrams are holding a vacuum. Off we go.

Roy James

I have an ACV ill just about give away, anyone interested? Its off an 88 N/A. To my knowledge it works fine, if someone can give me a way to test it I'll be more than happy to test it bf it throw it out to whoever. Hope this can help someone.

J-Rat

iTrader: (2)

What about checking the injectors? I assume that the local Auto Zone will look at me like I am nutso...Where do you send these damn things? And what about getting new ones? Sorry that you have my problem now..But at least we can work together to fix it.....!!!

Rat

J-Rat

iTrader: (2)

HAILERS, I pm'd him and asked for the ACV. I dont know if its the problem, but I am willing to try anything. I also have an ECU on the way, although I dont think that is the prob. My guess??? Leaky injectors. But like I said, I need to either send them off, or get new ones...

RAt

Roy James

hey man, i hit you back on that PM. you know of a way to test it? i would hate to give out a bad part to someone. Thanks

J-Rat

iTrader: (2)

I dont know of any sure way to test it...I got one from the junkyard for $20, but I dont think it works. You really have to put it on the car, then check the Port/split air for operation. I also had to Fabricate a gasket cause the one from the old ACV got torn. COuld be part of my problem. But I havent a clue where to get new gaskets. OR the check valve behind the ACV for that matter. HAILERS may know how to check it, or he may have an injector problem. He has more rescources to test with then I do..

Rat

J-Rat

iTrader: (2)

Roy James, did you get my PM??

HAILERS

Back. The car is back together. Changed the primary injectors with a pair I check out last week. Put another acv on the car that has been sitting on the shelf so to speak. Checked it out prior. There are two holes that are one half inch from center to center. These holes are on the gasket side. The top one is switching and the bottom relief. I put a mitty vac on the top one and the poppet in the one inch hole moved and help vac. Did the same to the lower hole. Looking in from the other side I could see the relief valve move. It can be seen thru the large snout. When I started the car it acted just exactly as before. No difference. So I would not go out and buy injectors. Its worth saying right here and now, that although my meter shows .8 and damn near .9v, even if I make this (wifes) car read .01 or so at idle, this does not mean the mixture has changed. Right now the way I see it(starting to wonder if I'm wrong)if I make the wifes car work like my 87na which shows .003 at idle, it does not mean the mixture is really leaner. All I have to do to my 87na to read high, is to cut the air pump belt or take it off. The way I see it on the 87na, is that the acv is mixing fresh air with the exaust gas prior to reaching the 02sensor, and that is why it reads .003. The wifes car is not getting this fresh air so it just sees the exaust gas without the fresh air and reads high. By the way, the wifes car smells like sulfur. That pig has smelled like that the last couple of years and passed emissions.
I'm more or less lost right now. I put a tap on the water thermo sensor and it reads .50 hot like my other cars. I might swap the 86 and 87 acv tomorrow if they don't bust my ***** at work. I gotta reasses my thinking on the acv. I did note one small thing. When I turn the car off and then restart, the o2 reads .003v or so for about 9seconds then goes to the .850v. Repeated that four times. Don't know what to think about that.
Hey JRAT. If you put a vac hose on either of the two nipples above the acv you should be able to hold a vacuum on them. The fwd one is switching and the aft nipple is relief. If they hold vac that is a good sign that they are good.