Help, looking for emissions experts!!!

[mike100]

high nox will be due to high combustion temps/engine lugging and loading...too high initial ign timing , high compression, running lean due to vac leak etc.

The C02 should be higher- this is a by product of a proper fuel mix and a healthy Catalyst.- like 14%-15% of the total exhaust output. i'm not sure how to convert to gm/km. seems like the C0 and Hc is too high which means you are 'hella' (to borrow some bay area vernacular) rich at low speeds.

is this test on a loaded dyno or an idle test?

[mike100]

Also, see if they have 02 results (unburned extra oxygen).

the linked page below is the best resource i have ever seen and I used to do smog work back in the 90's. great cross reference. get some 02 info and it will lead you to the condition.

http://www.ratwell.com/mirror/interro/techgas.html

still seems like the medium high HC and the high CO means a rich condition. try a stock eprom with no power enrichment. The cam overlap is probably the reason the NOx is really low, but that does contribute to dirty combustion. try to get them to do the whole test at higher rpms or in 1st gear.

[HAWAIIZR-1]

Originally Posted by mike100

Also, see if they have 02 results (unburned extra oxygen).

the linked page below is the best resource i have ever seen and I used to do smog work back in the 90's. great cross reference. get some 02 info and it will lead you to the condition.

http://www.ratwell.com/mirror/interro/techgas.html

still seems like the medium high HC and the high CO means a rich condition. try a stock eprom with no power enrichment. The cam overlap is probably the reason the NOx is really low, but that does contribute to dirty combustion. try to get them to do the whole test at higher rpms or in 1st gear.

Mike,

Thank you and CA is very strict so your tips are valued. They will not discuss in detail or provide any how to fix it tips, in addition there is a huge language barrier. Thanks for the explanation of the high CO and HC and I have some studying to do on this. I will have to take up Tom on the loan of his stock chip or find one to purchase and see how that does and might be my best bet, but I do have to find somewhere to test before making the grueling 6 hour trip. The next time I go there I want to be sure I will pass. Thanks again! Craig

[HAWAIIZR-1]

Originally Posted by XfireZ51

Craig,

Never mind. Bit of a mental lapse on my part. DOH!

Thanks Dom. Hey, I can't even remember yesterday and I'm still wondering what the other bung is for and might have to try to get under there and post a photo. Here is a pic of a 90 and it does not have the other one I am talking about on the pipe after the converter, but the O2s can be seen:

[tomtom72]

Hey Craig, just give me a address that I can do a UPS or FEDEX to you with my OEM PROM.......no need to ask, just give me a place to send it!


Tom

My PROM has been more places than me and my ZR-1......what's wrong with that picture!?!

[HAWAIIZR-1]

Originally Posted by tomtom72

Hey Craig, just give me a address that I can do a UPS or FEDEX to you with my OEM PROM.......no need to ask, just give me a place to send it!


Tom

My PROM has been more places than me and my ZR-1......what's wrong with that picture!?!

Hey Tom,
As always, willing to give someone the shirt off your back. I'll PM you about this and greatly appreciated.

By the way, is seems my car is a porker as it weighed in at 1,600 kgs or 3,527 pounds with spare tire and tools removed. I don't know how accurate, but they sent me to a paper recycling place and I had to drive on a scale.

Craig

[zr1don]

I recently went through the new CA emissions testing and had a heck of a time getting my 90 to pass w/aftermarket cats. As you noted you passed NOX, which most of the time is the one that causes problems. Your high CO and HC's indicate a rich mixture. I don't know if you have access to a scanner/data logger, but you need to check what the computer BLM's and INT are doing at the speed and load conditions the test is done. Acording to your test numbers the INT numbers should be showing a rich mixture and the BLM's should be moving to lean the system back to soichemetric. If your car has not been run in the load and speed conditions the test is performed in, the ECM may not have had the time to correct the mixture. Bottom line you need someone who can correct the rich mixture condition.

I think the bungs behind the CATS were added for tuning. My 90 stock exhausts, like yours, did not have them.

[HAWAIIZR-1]

Originally Posted by zr1don

I recently went through the new CA emissions testing and had a heck of a time getting my 90 to pass w/aftermarket cats. As you noted you passed NOX, which most of the time is the one that causes problems. Your high CO and HC's indicate a rich mixture. I don't know if you have access to a scanner/data logger, but you need to check what the computer BLM's and INT are doing at the speed and load conditions the test is done. Acording to your test numbers the INT numbers should be showing a rich mixture and the BLM's should be moving to lean the system back to soichemetric. If your car has not been run in the load and speed conditions the test is performed in, the ECM may not have had the time to correct the mixture. Bottom line you need someone who can correct the rich mixture condition.

I think the bungs behind the CATS were added for tuning. My 90 stock exhausts, like yours, did not have them.

Hello zr1don,

Thanks so much and I appreciate the input. Yes, I have data master so I can do some recordings and check it out. I appreciate the explanation and it is like Japanese to me right now, but I'll do the research as they also have a manual from TTS to explains some of this. I don't know if I can get the details about the testing performed since I could not watch and was only brought in for the bad news part. I'm going to try to work with Marc H since he programmed the current chip.

Thanks for the explanation about the other bungs and it makes sense; maybe someone else will chime in about those that know. As soon as I came home today my service engine light came on so I'll see what codes it threw too.

Craig

[zr1don]

Most tests here in the US use 15 and 25 mph. Talk to Marc, you should be able to record a couple 5 or so minute sessions at 15 and 25 mph using your datalogger, send the files to Marc, and he should be able to make changes to correct the rich condition.

[zr1don]

I noticed in your original post you did not mention replacing the O2 sensors. When they get old or contaminated they usually send an incorrect signal that the mixture is lean causing the computer to richen the mixture. If you monitor O2 output with your Datamaster program and they are not providing a good signal, their output will show a lean mixture and the INT and BLM's will be trying to richen the mixture (incorrectly).

In your situation, where you know you have a rich mixture problem and the O2's are working correctly, they should show a rich mixture and the INT and BLM's should be working to lean the mixture back to soichemetric.