Passing emissions
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Joined: Jun 2002
Posts: 107
From: Vancouver, BC, Canada
Passing emissions
Doh! Failed AirCare this morning.
It was high HC at idle (114, 76 allowed) and high NOx driving (1291, 1014 allowed).
I don't have a working EGR setup, the valve was stuck open so that is where I'm failing. Any tips on how I can get it under the 1000 required?
I can burn chips, so I'm thinking raise the idle to 700rpm to get past the high HC problem, and lower timing to get past the NOx problem.
I also forgot to increase the tire pressure, I'll be sure to do that next time.
Edit: What about filling up with 91 or higher from Mohawk? Will that slow the combustion down to reduce NOx?
It was high HC at idle (114, 76 allowed) and high NOx driving (1291, 1014 allowed).
I don't have a working EGR setup, the valve was stuck open so that is where I'm failing. Any tips on how I can get it under the 1000 required?
I can burn chips, so I'm thinking raise the idle to 700rpm to get past the high HC problem, and lower timing to get past the NOx problem.
I also forgot to increase the tire pressure, I'll be sure to do that next time.
Edit: What about filling up with 91 or higher from Mohawk? Will that slow the combustion down to reduce NOx?
Last edited by AlexH; May 9, 2003 at 03:14 PM.
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Joined: Feb 2001
Posts: 3,842
From: BC, Canada
a few tips .. (im sure bunker will chime in as well . he knows his sh*t)
1) lowering ur timing will make ur NOx WORSE NOT BETTER .. because ur car will run a LOT hotter with lower timing and NOx gets created in a hot cumbustion .. the EGR merely cools ur cumbustion down to reduce the creation of NOx ...
2) Fix ur EGR system .. a valve is only about $30 and 2 nuts ! easy as pie
3)raise ur idle to higher than 700 .. if ur standard .. raise it to 1200 .. they dont really care as long as its not ridiculously high
4) lowering ur timing WILL help ur HC though.. and so will running methyl hydrate and cleaning ur cumbustion chambers with seafoam or the GM TEC (top engine cleaner) .. go buy a bottle and run it thru to clean the carbon build up . it did wonders on my beater cutlass
5) i have no idea how tire pressure would help u with ur problems ?!?
6) run 94 octane mohawk or chevron with half litre of methyl hydrate (half tank gas to half litre) dont go overkill on the methyl cuz it will have negative effects on other areas (NOx for one as it makes ur cumbustion hotter)
7) program ur fans to kick in earlier and / or take out ur thermostat to make ur car run REALLY cold (but hot enough to kick into closed loop.. u DONT wanna go thru aircare in open loop).. this will most certainly get rid of ur NOx (if ur too cheap to fix ur EGR system
)
8) also keep in mind that there is a threshhold in cumbustion temprature where u start trading off CO2 with NOx ... the colder u go the more CO2 u leave behind the less NOx u create .. the hotter u go the more NOx u crfeate and the more CO2 u burn off
1) lowering ur timing will make ur NOx WORSE NOT BETTER .. because ur car will run a LOT hotter with lower timing and NOx gets created in a hot cumbustion .. the EGR merely cools ur cumbustion down to reduce the creation of NOx ...
2) Fix ur EGR system .. a valve is only about $30 and 2 nuts ! easy as pie
3)raise ur idle to higher than 700 .. if ur standard .. raise it to 1200 .. they dont really care as long as its not ridiculously high
4) lowering ur timing WILL help ur HC though.. and so will running methyl hydrate and cleaning ur cumbustion chambers with seafoam or the GM TEC (top engine cleaner) .. go buy a bottle and run it thru to clean the carbon build up . it did wonders on my beater cutlass
5) i have no idea how tire pressure would help u with ur problems ?!?
6) run 94 octane mohawk or chevron with half litre of methyl hydrate (half tank gas to half litre) dont go overkill on the methyl cuz it will have negative effects on other areas (NOx for one as it makes ur cumbustion hotter)
7) program ur fans to kick in earlier and / or take out ur thermostat to make ur car run REALLY cold (but hot enough to kick into closed loop.. u DONT wanna go thru aircare in open loop).. this will most certainly get rid of ur NOx (if ur too cheap to fix ur EGR system
)8) also keep in mind that there is a threshhold in cumbustion temprature where u start trading off CO2 with NOx ... the colder u go the more CO2 u leave behind the less NOx u create .. the hotter u go the more NOx u crfeate and the more CO2 u burn off
Last edited by sideways_Into_3rd; May 9, 2003 at 03:41 PM.
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Joined: Jun 2002
Posts: 107
From: Vancouver, BC, Canada
Higher tire pressure means the car doesn't have to work as hard on the dyno. 
I guess I should quit trying to pass without EGR, I went and ordered a solenoid. Still got a few days to fix it before my insurance expires.
I guess I should quit trying to pass without EGR, I went and ordered a solenoid. Still got a few days to fix it before my insurance expires.
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Joined: Jun 2002
Posts: 107
From: Vancouver, BC, Canada
LOL. I got the new solenoid, and raised my idle. Passed with flying colours.
Before NOx: 1200
After NOx: 61 (Not a typo).
My HC's are still slightly high, but I passed. Any ideas on how I can improve these numbers for next time?
Before NOx: 1200
After NOx: 61 (Not a typo).
My HC's are still slightly high, but I passed. Any ideas on how I can improve these numbers for next time?
. But I made it.
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