73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: nucknoel89 on March 10, 2010, 07:21:40 pm
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Okay, so here in British Columbia we have this stupid emissions testing thing called AirCare. Anyway, I ran my truck through the testing facility last week and the only thing that I failed was the level of hydrocarbons in my exhaust during idle. How would I go about reducing my hydrocarbons? I assume it has to do with the air/fuel mixture?
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HC's are unburned fuel. If you can post your other results CO CO2 and O2 that would be great. Contrary to what people think HC's does not indicate a rich condition.
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Driving Test:
Hydrocarbons ppm: 56
Carbon Monoxide %: .06%
Oxides of Nitrogen ppm: 1280
Idle Test:
Hydrocarbons ppm: 1491
Carbon Monoxide %: 2%
Edit:
There's also a graph thing that shows basically what they wrote, on there's an O2 graph there, and it looks like a little over 5% 02,but it's hard to make out, and CO2 is 9-10% I think.
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You could drive a smart car. Lol but the dmv is making it harder for old gas burning trucks to pass I know it took me 4 times to Finally get my 86 to pass and it barley did after taking it to a shop. I was once told you can put a bottel of alcohol in the tank to help it burn cleaner but it raises I think the hc or o2 can't remember.
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Easiest, completely legitimate way to fix your problem with Air Care: Go into your favorite Autoplan broker and have the GVWR raised on your truck to somewhere (you pick ) between 5000 and 5500 kg. Voila! No more Air Care requirement. That's exactly how all the people you see in the Lower Mainland who have "No Air Care required" advertised for their trucks. Because we have commercial plates, this can be done. You don't need a reason either. You can just request to have your GVWR raised.
My brother in law did NOT do this to the older Dodge 1/2 ton he uses for a landscaping business. He was pulled over by a commercial vehicle cop while towing a fairly large, loaded trailer. Cop said because his GVWR wasn't high enough, he was overloaded and in violation. Brother in law asked him how that could be fixed and cop said to just go have it raised. I know, it does NOTHING for the safety of the truck, or the load, but it's legal.
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Looks like you can be easily put back into spec. Tell us more about your set up.
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Looks like you can be easily put back into spec. Tell us more about your set up.
Umm, not totally sure on everything, but it's a 305 with a 4 barrel carb. I don't know that much about carbs though. Oh, and if it makes any difference that charcoal canister or whatever it is isn't connected to anything. I don't have a catalytic converter either. Not sure what my timing's at either but I had it done at a shop in summer.
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It might help to have that canister connected. What it does is help burn off the fumes that can collect from the gas tank. That won't really help though your problem with the HC's. A cat converter would for sure help since that's exactly what they are for: to burn off excess fuel in the exhaust and reduce HC emissions.
I had a 2000 Dakota R/T that I had a gutted cat on plus some other bolt-ons. Went through AirCare and failed BAD. Dude at the station said to me "THere is something seriously wrong with your truck! You better get it fixed." I get the stock cat put back on, plus I put the stock computer back in and got it running nice and hot and took it through again. Passed and the test ended early because of the ultra-low emissions. I give the credit to the stock cat.
Before you go spending money on it though, look into the GVWR thing. Like I say, it's totally legit.
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get it running good, tune it a little lean, and then run like 4 cats on each bank ;D or just one on each
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Let us know what carburetor is on it. Tune it up and check the timing. Do you have a vacuum advance distributor? Is there a 4 wire plug coming off of it?
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Retarding the timing has helped me in the past.
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Let us know what carburetor is on it. Tune it up and check the timing. Do you have a vacuum advance distributor? Is there a 4 wire plug coming off of it?
The carb is a Quadrajet. How do I tune it up? And I don't have a timing light, is there still a way for me to check the timing? I'll go out here in a few minutes and look at the distributor
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Since you don't have a gas analyzer it'll be important for us to know where your timing is to help you. Replace your plugs (gap them correctly), wires, cap, rotor, air filter, pcv valve, breather & fuel filter. Clean the carburetor and replace the fuel filter. When your done check the timing so you have a baseline as to where it was at before you try to adjust it. Let us know about that distributor.
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Since you don't have a gas analyzer it'll be important for us to know where your timing is to help you. Replace your plugs (gap them correctly), wires, cap, rotor, air filter, pcv valve, breather & fuel filter. Clean the carburetor and replace the fuel filter. When your done check the timing so you have a baseline as to where it was at before you try to adjust it. Let us know about that distributor.
The plug has only 3 wires.
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seafoam it..