Emissions too high!
04-30-2005, 06:43 AM
#1
Burning Brakes
Thread Starter
Emissions too high!
Hey all
Ive just got my new turbo back from shipping it back from Duabi to UK. I will post some pics soon and whats it like to drive!
However I need to get it through the MOT or smog test... however it is way too rich. We have tried to adjust it but finding it difficult to lower it and the CO and HC are way too high...
The car has a B&B exhuast on it and on the stock exhuasts have a nipple on it before the O2 Sensor so you can adjust it properely but this one doesnt! So whats the best way to adjust the mixture with this setup? (we removed the O2 sensor and took the reading from the exhaust tip to try and reduce the co2)
There is a hayward and scott final exhaust with a CAT built into it.
Could there be a problem with anything tho.. O2 sensor? the head has been modified to run 40% more fuel for all the mods (GT2 cams,1Bar spring,K29 etc)
Trouble is i dont want to reduce the mixture too much it will start to run lean
Cheers
Ive just got my new turbo back from shipping it back from Duabi to UK. I will post some pics soon and whats it like to drive!
However I need to get it through the MOT or smog test... however it is way too rich. We have tried to adjust it but finding it difficult to lower it and the CO and HC are way too high...
The car has a B&B exhuast on it and on the stock exhuasts have a nipple on it before the O2 Sensor so you can adjust it properely but this one doesnt! So whats the best way to adjust the mixture with this setup? (we removed the O2 sensor and took the reading from the exhaust tip to try and reduce the co2)
There is a hayward and scott final exhaust with a CAT built into it.
Could there be a problem with anything tho.. O2 sensor? the head has been modified to run 40% more fuel for all the mods (GT2 cams,1Bar spring,K29 etc)
Trouble is i dont want to reduce the mixture too much it will start to run lean
Cheers
04-30-2005, 11:35 AM
#2
Rennlist Member
Hi Miles,
I'm not sure what the requirements are in the UK.
Here in the the US each state has it's own emmissions testing procedures.
My project car is a 3.6 turbo w/ Ghl headers ,BB muffler no cat.
I did get it to pass in Connecticut after several tries, which requires the test under load at 25 mph.( I found it better in 3rd gear for the test)
The procedure to adjust mixture is as follows:
Warm up to operating temp.
unplug o2 sensor
adjust mixture on fuel distritbutor w/ allen key clockwise to enrichen
Adjust CO at (about 875 Rpm) to leaner turning key in very, very small increments counter clockwise with engine off.
If you make it too lean HC will increase.
if you have a cat in good working order it should pass easily, use the OEM spec as a baseline.
reconnect o2 sensor see if it passes.
After test readust mixture so CO is around 3% without o2 sensor.
Good luck
Elliot
i
I'm not sure what the requirements are in the UK.
Here in the the US each state has it's own emmissions testing procedures.
My project car is a 3.6 turbo w/ Ghl headers ,BB muffler no cat.
I did get it to pass in Connecticut after several tries, which requires the test under load at 25 mph.( I found it better in 3rd gear for the test)
The procedure to adjust mixture is as follows:
Warm up to operating temp.
unplug o2 sensor
adjust mixture on fuel distritbutor w/ allen key clockwise to enrichen
Adjust CO at (about 875 Rpm) to leaner turning key in very, very small increments counter clockwise with engine off.
If you make it too lean HC will increase.
if you have a cat in good working order it should pass easily, use the OEM spec as a baseline.
reconnect o2 sensor see if it passes.
After test readust mixture so CO is around 3% without o2 sensor.
Good luck
Elliot
i
04-30-2005, 01:58 PM
#3
Burning Brakes
Thread Starter
Hi
Thanks alot for the feedback. Uk emissions is you must have a CAT after 1991. its about 0.3% CO at idle and max 200 HC.
I seem to remember we (me and my garage) disconnect the O2 sensor the adjusted the mixture, when we connected the sensor back but not much changed in the readings... If the sensors not working I will change it for another one. Will see what happens after that!
Cheers
Thanks alot for the feedback. Uk emissions is you must have a CAT after 1991. its about 0.3% CO at idle and max 200 HC.
I seem to remember we (me and my garage) disconnect the O2 sensor the adjusted the mixture, when we connected the sensor back but not much changed in the readings... If the sensors not working I will change it for another one. Will see what happens after that!
Cheers
04-30-2005, 06:34 PM
#4
Rennlist Member
Miles,
BTHW: a cat is required here as well ,but by fooling atound with the mixture It was able to pass any way ,that is why you should pass easily, Change the 02 sensor and see if that does it.
Elliot
BTHW: a cat is required here as well ,but by fooling atound with the mixture It was able to pass any way ,that is why you should pass easily, Change the 02 sensor and see if that does it.
Elliot
05-01-2005, 05:59 AM
#5
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
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The sound of my engine at idle changes when I unplugged the o2-sensor on my car.
You are supposed to meassure duty cycle to tell if the o2-sensor works or not, but over the years I have never figured out how to do that on these cars (tried every combination at the diagnosis port with a dwell meter).
To my understanding, the usual problem when meassuring emission on these cars (stock cars thought) is that they show a lean condition when meassuring from the exhaust tip because of the air pump. But I doubt you use your air pump.
In Sweden they meassure emission twice, at idle and 2.500 rpm.
I disconnected the air pump and was a bit worried the numbers would be bad at emission test.
I installed a data logging unit from www.zeitronix.com and used it for tuning my AFR.
Had no problem in getting it just where I wanted it, it was so good my clutch started to slip (another story) :-)
My numbers at the emission test was perfect, I asked the test guy twice since I didn't want to install the air pump after I removed it. He told me -"It doesn't get better than this".
I can really recommend installing something that reads AFR especially if you run more than stock boost. You sleep better at night. My unit is logging a lot of parameters, thinking about getting an accelerometer and connect it to the unit, then I would have my own dyno.
You are supposed to meassure duty cycle to tell if the o2-sensor works or not, but over the years I have never figured out how to do that on these cars (tried every combination at the diagnosis port with a dwell meter).
To my understanding, the usual problem when meassuring emission on these cars (stock cars thought) is that they show a lean condition when meassuring from the exhaust tip because of the air pump. But I doubt you use your air pump.
In Sweden they meassure emission twice, at idle and 2.500 rpm.
I disconnected the air pump and was a bit worried the numbers would be bad at emission test.
I installed a data logging unit from www.zeitronix.com and used it for tuning my AFR.
Had no problem in getting it just where I wanted it, it was so good my clutch started to slip (another story) :-)
My numbers at the emission test was perfect, I asked the test guy twice since I didn't want to install the air pump after I removed it. He told me -"It doesn't get better than this".
I can really recommend installing something that reads AFR especially if you run more than stock boost. You sleep better at night. My unit is logging a lot of parameters, thinking about getting an accelerometer and connect it to the unit, then I would have my own dyno.
05-03-2005, 08:54 AM
#6
Burning Brakes
Thread Starter
Hey Staffan! Thanks for the post.long time no speak...
That sounds just the ticket! I thought I would have to put it on a dyno all the time to get the A/F ratio.
I just went back today with a REAL hot engine (unpluged the oil cooler relay) and this is what I got from the exhaust tip:
With O2 Sensor:
CO2 .60%
HC 150
Without Sensor:
CO2 .20%
HC 250+
Our tests must be Co2 <0.3% and HC<200. Im not sure if the sensors working or not or why the Co2 drops when you unplug it. We have tried to tweek it down a bit but nothing seems to be happening- expect the hotter engine did a noticable difference but not enough... any ideas?????
Cheers
That sounds just the ticket! I thought I would have to put it on a dyno all the time to get the A/F ratio.
I just went back today with a REAL hot engine (unpluged the oil cooler relay) and this is what I got from the exhaust tip:
With O2 Sensor:
CO2 .60%
HC 150
Without Sensor:
CO2 .20%
HC 250+
Our tests must be Co2 <0.3% and HC<200. Im not sure if the sensors working or not or why the Co2 drops when you unplug it. We have tried to tweek it down a bit but nothing seems to be happening- expect the hotter engine did a noticable difference but not enough... any ideas?????
Cheers
