This is topic Excessive HC emissions in forum Tech Talk at Northern California Ford Owners .
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Posted by 86GT_Hatch_Pearl (Member # 13762) on
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Just took my 86 GT for smog the other day. NOx and CO were just fine, but HC was about 30 ppm over the max limit. I had a similar issue last time, replaced the EGR vacuum control solenoid and solved the issue. I did an ignition tune-up less than 5 months ago, I doubt the plugs are that fouled. I also recently replaced the smog pump. I was thinking of replacing the solenoid again and possibly the EGR valve itself. Any suggestions or thoughts?
Posted by hurting your feelings (Member # 13641) on
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Drive the piss out off it an the hc should drop the catalyst most likely warmed all the way or the car cooled down.
Posted by 3cRider (Member # 10052) on
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I believe Ca lowered the limits a few years ago (I don't know if it was NOX, CO, and hydrocarbons or just one of them) and it's only gotten harder to pass. Cars that once passed with a good margin suddenly don't have as much wiggle room.
But like Hurting your feelings said, get the cats good and hot! Some have even thermal wrapped them to ensure they stay hot.
[ 2014-12-13, 03:18 PM: Message edited by: 3cRider ]
Posted by SacStangDriver (Member # 8304) on
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if you got a friend who is a smog tech. pull the spout connector and it sho uld pass
Posted by Tom Renzo (Member # 13165) on
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Install a dummy spout connector and go through emissions
Posted by hurting your feelings (Member # 13641) on
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Just drive the shit out of it an when show up to the smog shop have smog right away.it failed because the catalytic converter's had time to cool down.
Posted by SacStangDriver (Member # 8304) on
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tom renzo! never thought of this. thanks.
Posted by hurting your feelings (Member # 13641) on
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quote:
Originally posted by SacStangDriver:
tom renzo! never thought of this. thanks.
You can cut the wire going to the connector an install but connector's so you only have to un-hook the wire when smogging the car.
Posted by dohcfox (Member # 12829) on
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Too rich.
Posted by 86GT_Hatch_Pearl (Member # 13762) on
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Failed again! Cleaned out the EGR valve, check valves, throttle body and the spark plugs and ran 101 octane unleaded race fuel from 76...it dropped HC emissions, but not enough to pass. Still 10 ppm over the limit. I drove the car for about 20 miles and didn't shut the engine off until the smog tech took it. I'm starting to wonder if that loose wire my buddy found in my spout connector was my savings grace at the last smog check. This is rather frustrating.
Posted by hurting your feelings (Member # 13641) on
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Driving for 20 minutes will not get the cats hot enough drive hard for about a hour.
Posted by Tom Renzo (Member # 13165) on
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Not to rich it can be lean and increase the numbers as well. Normally advanced timing can do it and removing the spout will let you sail through the test if your engine is in good shape with no other issues. Did you disable the SPOUT ????????????? Everything you did prior to the test was useless as you found out. HC is unburnt fuel. Your timing is to high. Fudge the spout and or reduce the timing. Not sure if CA checks base timing i think they do. DID YOU DISABLE THE SPOUT>>> YES>>> NO ???
[ 2014-12-24, 02:45 AM: Message edited by: Tom Renzo ]
Posted by hurting your feelings (Member # 13641) on
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Yes we check the timing.
Posted by 86GT_Hatch_Pearl (Member # 13762) on
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No, I didn't disable the spout. I'll do that the next time I go, since all I have to do is pull the wire slightly out of the connector's socket. ..its already loose.
Posted by 86GT_Hatch_Pearl (Member # 13762) on
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No, I didn't disable the spout. I'll do that the next time I go, since all I have to do is pull the wire slightly out of the connector's socket. ..its already loose. Base timing is at 10 degrees.
[ 2014-12-24, 11:23 AM: Message edited by: 86GT_Hatch_Pearl ]
Posted by 86GT_Hatch_Pearl (Member # 13762) on
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[ 2014-12-24, 11:20 AM: Message edited by: 86GT_Hatch_Pearl ]
Posted by rollininmy50 (Member # 9067) on
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Is this a stock motor? There is a tube that connects both heads together , back side against fire wall, is this tube free flowing? Blow threw it, 9 out of ten cars looked at the tube is clogged . Plus Where this tube connects to at the heads could be clogged as well. If your car cannot breath it will fail. If the car is stock the timing should be at 10' , you don't need 101 octane to smog a car, if it was manufactured with 89 octane that's what you use. Period. Many of stangs have failed due to thats mission tube on the back of the motor.
Posted by 86GT_Hatch_Pearl (Member # 13762) on
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Well, the spout connector bit didn't work, it only made it worse. Looks like I need some new cats. It's something of a bummer, since I replaced the two main cats approximately 7 years ago. I'd go with magnaflow's direct-fit CARB legal piece, but the cost is a little out of my price range. I can only hope my muffler shop can work some magic with the stock H-pipe again for a reasonable price.
Posted by Tom Renzo (Member # 13165) on
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I find that hard to believe. reducing the timing will always decrease HC significantly.
Posted by 86GT_Hatch_Pearl (Member # 13762) on
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I thought it was strange, too. What you said made perfect sense. When disabled, the HC levels rose slightly more (135 ppm) and CO was readable..reconnected it and ran it again, HC went back down to about 126 and CO down to 0. Something strange about this. Combination of sensors and cats, maybe. I could smell the unburnt gas in the exhaust when it was on the dyno.
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