J-Rat

iTrader: (2)

Here is the deal. I have an 87 N/A. Its failing emissions like crazy. I have already talked to "Exhaust Works" the local muffler people and he said that with numbers like mine, there is no way a new Cat is gonna fix the problem, and I am not ABOUT to surrender my car to the local Mazda dealer. I have changed the Air filter, plugs, wires, O2 sensor, oil, oil filter, etc... The car doesnt flood, and doesnt blow smoke out of the back. It doesnt hesitate nor does it surge at idle. And it runs all the way to the redline with little or no hesitation. So it seems happy except for the fact that the exhaust will make your eyes water. The cats are hooked up and I have already replaced the ACV. Does anyone have any clue as to what may be the problem? I already tried to run alcohol (against my better judgement). And I have read just about every thread that I could.

Rat

niner

what do you mean? the mileage? or the HC #s?
do you know what the compression is on it?
i do inspections and a new cat is kinda a last resort thing
have you tried the stuff from parts stores, the "guaranteed to pass" kind of stuff
do you actually have the HC numbers from the emmissions machine?

J-Rat

iTrader: (2)

Oh yeah, I have all the numbers...They are posted under the thread "Does alcohol hurt my7" or something like that. I will give them to you if you like. I tried GTP, and the numbers got better but they are still pretty bad (they improved 50%). The motor is brand new so I hope that the compression is good. The only thing I can think of right now is that the idle mixture needs to be set. The tech manual says that if you put a new motor in that this needs to be adjusted. The idle numbers seem to be the worst ones.....But like I said, the exhaust smell is STRONG..

Keith

Here is a thought. If the car is running way rich, either you have a sensor problem or a nutty ECU. If it is a sensor problem, I would suspect the Water Thermosensor under the alternator, or the Air Temp sensor, both the engine one and the AFM one. Wouldn't hurt to check the AFM for voltage (with ignition on and meter on the green/blue stripe wire on plug, open flapper valve. voltage should vary from 4V closed to .5 wide open flap, smoothly and linearly). If all this checks out, try another ECU.

Oh, one other thought - are these the correct size injectors? This kind of problem can happen if the injectors are oversize w/stock ECU, for a given duty cycle the injectors will inject way more gas - hence, Rich!
Good luck!

Irv, Keith's dad

J-Rat

iTrader: (2)

what about the EGR valve? i hear that it can cause this problem too. At any rate, it looks like I am gonna have to take the top half of the motor apart to get a look at the injectors. Is this hard?

J-Rat

iTrader: (2)

If I get the injectors out, how do you tell if they are the right or wrong ones? And where can I get them cleaned and balanced?

J-Rat

iTrader: (2)

If I get a new ECU, I would want an aftermarket one. I went to HALTECH.com but I couldnt figure out which one would be good for the 87 N/A. I am not trying to make my car into a fire breathing dragon, but I do plan to do some mild mods to it.

HAILERS

Try checking out that water thermo sw at the back of the water pump, like Keith suggested. You can go to the ECU under the passengers feet with your meter. Find a good ground nearby and then put your meter on wire or pin if you will, 2I. The pin 2I is located on the second largest plug(18pins), and 2I is on the top row, fifth one over from the right. With the engine fully warm, and the plugs hooked to the ECU, Put your meters probe into the back side of 2I(a green wire with a white stripe). My car reads .50 to .51 volts fully warmed up. Cold will differ, usually over 1.21volts then. You can look at pin 2L, bottom row 4th from the left, GREEN WIRE. Should be 1-2 volts. That was the intake temp sensor in the dynamic chamber. Then look at pin 2J, bottom row, fifth pin over from the right, green wire with orange stripe. Book says 2-3v at 68 degrees. Might check pin 2B also. Bottom row, far right, brown wirew with a red stripe, should be about 2v at idle. NOTE: With all plugs hooked up, and looking into the ECU jack, the pins are lettered from right to left. The top right pin is A, the pin just under it is B. The next top pin is C and the one under it is D and so on.

J-Rat

iTrader: (2)

Where did you get the pin-out for the connectors? The service manual? I am gonna need to know which pins correspond to the equipment so I know what is bad if anything tests bad. Good idea though!! I like that! Saves the trouble of pulling everything out. I will be sure and do the tests and get back with results..

Rat

HAILERS

This site http://www.iluvmyrx7.com/Technical_I...ice_manual.htm is the factory service manual for a 88 rx7, both turbo and N/A. Download the FUEL SECTION and you will find in the Fuel Section, a sub section on the *Control Unit*. Near the beginning of that section there are about four pages that show the values for each pin at idle and with just the key on. 'Thats where I got the info in the earlier post. Slight problem here.....at home I have a 87 paper manual. It, like the online manual has two fuel sections, one for turbo, one for N/A. I just noticed this day that the downloaded 88 manual on my computer does not have the *Control Unit* pages I mentioned above for the NA. If you download the fuel section for the N/A and do not see the three pages detailing what the pin readouts are, then download the fuel section for the Turbo Fuel. Virtualy all the pins read the same for turbo vs N/A. At this time I can't tell if I downloaded the fuel section for the N/A wrong or if that *control unit* part does not exist there. Sorry 'bout that. EDIT: Pages 4B-31 thru 4B-33 have the info I refer to. The NA section should have had the same.

J-Rat

iTrader: (2)

Yeah, I have the section that you are talking about. I just printed up the section 4A (88 pages) and was gonna run the tests that it specified. Only trouble is that the car runs great so the troubleshooting tree is worthless to me. Seem like a better idea and its more accurate to just check the signals at the ECU with the ECU plugged in. We all know that the ECU probably drags the voltages down some. I pulled the plugs the other day after being in the car 2 days, and the plugs were BLACK. I was just hoping that there was a common problem that people had with 87's that caused this, but it looks like I am gonna have to get down and dirty with my multimeter. I plan to check the TPS, and the Idle mix and test the EGR. I read somewhere that the EGR can cause these problems. I would like to make sure that i can eliminate as many adjustments as possible before I start shooting wires. If I need an ECU, can you reccommend a better one then stock?

Rat

HAILERS

NO. I see what has happened. I'm not refering to any of the trouble shooting pages. Like I said in the above post, the fuel section on the N/A, Section 4A, has been shortchanged. Go to the Fuel section for turbos, and download it or just look at pages 4B-31-33. It shows the value of each pin on the ECU and shows the plugs and pin numbers. Trust me, the NA Fuel is not complete. Write back if you do not see what I'm talking about. Thats after you look on line at the Fuel for Turbos, pages 4B-31-33. The values are almost completly the same.
The 87 manual is superior to the 88manual.

J-Rat

iTrader: (2)

Oh, I understood what you were saying!! Go to the turbo fuel section (4B) and use that as a guide for t-shooting the ECU, and other things. You are saying in effect, check the signals at the ECU, if the signal is bad, check the associated equipment. If the associated equipment checks good, its a good possibility the ECU is fried. I spoke to the local RX-7 guy and he seems to think that the secondary air is gone, and the cats are gone (but I am getting air to the cats, I think its called split air). No one here I can think of can diagnose the car with the proper tools. I assume that the "NO" meant that there are no good ECU replacements if it happens to be that? My intention here is to get the car running in stock form, but usually the factory ECUs are outrageous. The other part I was talking about was at least making sure that the TPS and the Idle Mix were set up so I dont start finding more problems that could have been avioded by properly setting up for the tests. I am trying to eliminate as many possibilities as I can before testing. I am trying also to get another RX-7 over to my house so I can compare the wiring. I have some wires hanging around my engine bay that arent diagnostic ones, and I havent a clue where they could have gone too. Could be that the ECU might tell me eh?

Six Rotors

iTrader: (17)

Yes well have you checked the fuel rail pressure?Just did an 88 N/A which had fairly huge emissions~600ppm HC,3.2%CO and 22ppm NOX(I know the nox is great).Anyway the clown who installed the factory rebuild got the vac line wrong and the car was running 40psi in the fuel rail ALL the time.It passed with 86ppmHC and 0.1%CO today(I cheated a little by disconnecting the vac line from the switching valve and plugging it,thus flooding the cat with air continuously)

HAILERS

Whoops. I was wrong about the section 4A not having the pin outputs for the Control Unit. For some unknown reason the download I have at work does not have it, but the one at the house does. No good explanation. Sorry about the confusion. I don't think it will take much more than 30-45 minutes to check the pins out. Oh, and the NO in the other post had no connection to the ECU. I doubt the ecu is bad. Seems like the engine could just be worn down or the catalytic converter has flat given up. Had a 82 that was a combination of being worn out along with the cat being kaput. Bought a aftermarket cat and passed like a champ, but the engine gave up the ghost a little over a year later. A truly worn out and abused engine. Resulted in me learning how to rebuild a engine, which was a plus. SixRotors is the man(well Irv is also) when it comes to the fuel and emissions system. Seems he is suggesting that the switching solenoid be capped off at the vac line that goes to the switching valve that is inside the acv, which in turn prevents the airpump air from going to the port air passage, but instead goes to the split air pipe directly to the catalytic converter. Ref page 4A-38

J-Rat

iTrader: (2)

Hey six rotors, what is the pressure supposed to be? and so you think that i could pass by capping off that vac line?

J-Rat

iTrader: (2)

And which vacuum line to the fuel rail are we talking about?

J-Rat

iTrader: (2)

Hailers, unfortunately (or not depending how you look at it), the motor is brand spanking new from Mazda. So I am ruling out the motor as being the problem. There has to be some explanation as to why its running so rich. I may try the capping valve trick because I really want to drive the car legally. I havent been able to drive it for more then a few blocks and the engine isnt getting broken in like I would like.

J-Rat

iTrader: (2)

One last thing, I looked at 4A-38 but I am not sure which or where the vacuum line is and where he disconnected it from.

HAILERS

Looking straight at the acv from the r/h side of the car......near the top of the acv you see one nipple pointing straight at you, thats vac for the boost/pressure sensor. Now just to the left of that nipple are two nipples with vac hoses that come from the rear of the engine. Well the front one of those two nipples is the one that controls the *switching* valve inside the acv. At idle there is a vacuum on that line. Well that vacuum comes from the other side of the engine. It comes from the Gray solenoid on the drivers side. Should be the third solenoid from the front. I believe Sixrotors plugged the vac line as it comes out of the gray solenoid and heads for the acv on the other side of the engine. You could plug the line that goes to that nipple near the top of the acv, the front one of the two. That rear nipple is a vac that comes from the *relief solenoid* valve. If the engine is running and you take that line off the nipple at the acv, you feel a vac from the vac hose. If at the same time you reach over to the Blue solenoid and take its elec plug off, the vac will disappear. Any of that make sense??? SixRotors ?

J-Rat

iTrader: (2)

Yeah, it makes sense. I just wish that I could find the real reason the car is failing, but for now, I will take what I can get. I wonder if that would help me pass...Sounds like I could have some mis-routed vacuum lines.. The motor was not put in by me, but some of my cousins who had NO idea what they were doing. The car actually sat for a year with the new motor in, because they couldnt figure out how to get it started. I got it started in 5 days...Kinda makes you wonder what else they screwed up, doesnt it?

Six Rotors

iTrader: (17)

I mentioned two separate things:
1.the fuel rail pressure---at idle,with the vacuum line connected to the fuel pressure regulator,the fuel rail pressure should be ~28-30 psig,with the vacuum line disconnected at the regulator,it should be 35-40 psig--all the cars I have measured when the fuel regulating system is working have been around 35psig.High fuel pressure will make your car run rich.So make sure the fuel pressure regulating is working.(See Mazda manual,p4A-65/66/67.)
2.You can divert the secondary air injection system to ensure continuous air to the cat(for the test only).You can accomplish this by removing the vacuum pipe to the switching air valve,at the ACV.Lift the vacuum pipe closest to the front of the engine on top of the ACV and plug the open vacuum pipe.I use a suitable diameter bolt.The nipple above the ACV can be left open for the duration of the test.
I should also say that on the car I talked about I did a full engine signal monitoring test when trying to determine why it failed (all the sensor inputs and ecu outputs were normal).Then I checked fuel pressure and fixed it.

J-Rat

iTrader: (2)

WOW!! I wish someone around here could do full signal monitoring. How much of a number reduction can I realistically expect by blocking the switching solenoid? My numbers arent very pretty...

J-Rat

iTrader: (2)

I am astounded at the lack of support I am getting from mechanics in this area. Almost nobody will even get near these cars! Whats the deal?

Six Rotors

iTrader: (17)

These are old cars,Mazda hasn't trained anybody on them for years,the old ones who were trained have moved on,many dealers may have given up on the old signal monitors--you know all that kind of stuff.
I couldn't give you a number ,there are too many variables.I happen to think that fuel pressure may be a big part of your problem--because you are running rich all the time--dodgy sensors usually cause rotten running which I haven't heard you complain about.