Smog inspection, Help!

[jerry12345]

Help with smog inspection please! I bought an 88 Turbo automatic as a bit of a basket case. Broken timing belt and a lot of the engine in the hatch. After assembly it runs fine but will not pass California smog inspection. Here are the results:

At 15mph and 1733rpm the measured CO2% was 13.90, O2% was 0.38, HC (PPM) was measured at 178 and the max allowed is 106. CO% was measured at 1.07 with the max allowed 0.70. NO was extremely low at 32ppm

At 25mph and 1708rpm the measured CO2% was 13.69, O2% was 0.35, HC (PPM) was measured at 194 and the max allowed is 81. CO% was measured at 1.27 with the max allowed 0.57. Again the NO was very low at 64ppm

After buying the car I found out that the car had failed smog 6 consecutive times. Not really sure what the owner was trying to accomplish.
So far I have replaced the O2 sensor, air filter, spark plugs and realize that I probably need a new Catalytic converter. I hesitate to do this right now because I believe that the car is running very rich. I wiped out the tail pipe and took the car on a 20 mile drive. By the time I got home the tail pipe was again coated with a heavy layer of fluffy soot. Seems to me that if it is running that rich, I am just going to poison the Catalytic if I put a new one on it this condition?
I guess I have two questions. What would cause this thing to run so rich? Or, will a new catalytic fix the problem? I personally doubt it.
Any advice appreciated.

 

[3p141592654]

The numbers do indicate it is running rich.

Have you pulled the plugs? You may find one plug is black suggesting a leaky injector for that cylinder. They may all be black and then it might be a leaky cold start injector.

Is the check engine light on? Have you checked for codes as per below?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=23

 

[stan]

check your TPS, you may be running in open loop. i'm no expert, but that was the problem with my 88T when i got it (besides a few intake leaks and a bad bypass valve as well).

 

[stan]

also for what it's worth, i was told that it is pretty unlikely you will get a bad cat, they are supposed to be pretty darn good on our cars. i say check for codes because it sounds like when i had my bad TPS

 

[89_turborunner]

Check out the AFM device and the wiring to the O2 sensor. make sure the right readings are getting to the ECU....

You are running cold. One other thing to try is this:

Put premium in the car, and run the @#$% out of it before you go to the SMOG place. NOs will be high if you run hot, and running hot burns up CO and HC. So trade them around... heat it up.

 

[3p141592654]

The coolant temp is a good suggestion, and check to make sure the thermostat isn't stuck open. That will make the car never go out of warmup mode. One clue would be if the idle is high, suggesting it may be staying in warmup mode with a rich mixture. We really need to know if any codes are being set.

I am confused about the TPS comment. If the TPS is out of adjustment the idle would be off, but it should stay closed loop. In any case, you can check that easy enough by looking for proper code 51 behavior in diag mode.

 

[supraman7mgte]

I have experienced black sooty deposits on my exhaust tip before,that was due to a IC leak. Check your hoses.
Do a extensive search because running it like that will kill your O2 sensor as well.

 

[jerry12345]

The numbers do indicate it is running rich.

Have you pulled the plugs? You may find one plug is black suggesting a leaky injector for that cylinder. They may all be black and then it might be a leaky cold start injector.

Is the check engine light on? Have you checked for codes as per below?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=23

 

[jerry12345]

Thanks for the reply. Always appreciated. The plugs are new. I will pull them tomorrow. Check light is off and I checked for codes anyway. None to be found. I was tinkering with the idea of a bad cold start injector. Have you found a way for a mere mortal to disconnect the witing to the cold start?

 

[stan]

I am confused about the TPS comment. If the TPS is out of adjustment the idle would be off, but it should stay closed loop. In any case, you can check that easy enough by looking for proper code 51 behavior in diag mode.

the TPS can actually get stuck as well, and in my case the spring mechanism being worn out on it caused it to never get out of open loop.

 

[3p141592654]

Stan... I'll leave it to JetJock to explain that one.

Jerry, the CSi is a pain. It is possible to get the wiring clip off by removing the 3000 pipe and going in under the throttle body with valve cover off..

no codes... have you checked the cross counts on the O2 sensor. Also, what is the Vf voltage.

 

[jerry12345]

Stan... I'll leave it to JetJock to explain that one.

Jerry, the CSi is a pain. It is possible to get the wiring clip off by removing the 3000 pipe and going in under the throttle body with valve cover off..

no codes... have you checked the cross counts on the O2 sensor. Also, what is the Vf voltage.

 

[jerry12345]

Thanks will try to get a look at the CSi tomorrow as well as the plugs. Can you explain the crosscounts on the O2 sensor are? also, what is the Vf voltage?

 

[jerry12345]

Check out the AFM device and the wiring to the O2 sensor. make sure the right readings are getting to the ECU....

You are running cold. One other thing to try is this:

Put premium in the car, and run the @#$% out of it before you go to the SMOG place. NOs will be high if you run hot, and running hot burns up CO and HC. So trade them around... heat it up.

 

[jerry12345]

I don't believe that it is running cold. The temp gauge comes up (midrange)and I can feel the hot water start to flow to the rediator. Also it idles down correctly. Tried a can of "Gauranteed to Pass" and a full tank of premium. Then after I burnt that out, I refilled and drove the devil out of it before going for inspection. No good.
I have a question about the AFM however. Hope somebody knows the answer. Looking into the output side (away from the filter) and directly under the arrow in the casing is what seems to be some sort of air bypass. It may be about an inch wide and 1/4 inch high. It has a screw extending in to it. Goes in to where it blocks about 3/4 of the passage. It is obviously an adjustment of some sort, but for what? I haven't touched it, but as I said, this thing has had some real special attention given to it before I decided to try to ressurect the damned thing.
Appreciate it.
Jerry

 

[jerry12345]

check your TPS, you may be running in open loop. i'm no expert, but that was the problem with my 88T when i got it (besides a few intake leaks and a bad bypass valve as well).

 

[jerry12345]

Hate to hang out my ignorance, but could you tell me what and where the bypass valve is? How do I test it. If it is the wastegate, I kind of doubt that it is the problem. When I kick it, the boost pops right up to 7lbs and hold as long as I stay on it. Is that what we are talking about?
Jerry

 

[jetjock]

Stan... I'll leave it to JetJock to explain that one.

I'm not even gonna try. Besides, the TPS is easily tested.

Jerry: The tailpipe is, as 3p correctly stated, slightly rich in both cases. The 15 mph test calculates out to a lambda of .979 or an A/F ratio of 14.39 while the 25 mph test comes out to .971 or 14.28 A/F. Just slightly rich. 3p's advice to measure Vf and O2 cross counts is a good place to start. I'll add to that the average sensor signal as even more important. Confused? RTFM. And yeah, codes would be nice....

 

[jerry12345]

I'm not even gonna try. Besides, the TPS is easily tested.

Jerry: The tailpipe is, as 3p correctly stated, slightly rich in both cases. The 15 mph test calculates out to a lambda of .979 or an A/F ratio of 14.39 while the 25 mph test comes out to .971 or 14.28 A/F. Just slightly rich. 3p's advice to measure Vf and O2 cross counts is a good place to start. I'll add to that the average sensor signal as even more important. Confused? RTFM. And yeah, codes would be nice....

 

[jerry12345]

I think I am dealing with the worng manual. I am trying to use a Chilton's and also the TSRM on Cygnus. Very very little of what you are talking about shows up. This has become a challenge and I want to get the right documentation. Reccomendations?