HC is unburned fuel, which means something is preventing full combustion such as a misfire, or something is soaking up fuel i.e. carbon deposits. What's the CO reading? When I last smogged my cammed and modified 289 I passed with ~700ppm HC. A few things that can clean up HC: long, hot drive, oil change, clean plugs, and hotter thermostat. A carb adjust might help if the CO reading is high, meaning the engine is running so rich it's misfiring. A carb adjusted too lean will also cause the HC to shoot up because of a lean misfire.
Along with the plugs/wires, you might also want to change the cap/rotor on the distributor.
Edit:
67s didn't come with 302s they came with 289s. Are you sure that is a 302 in there ?
I'm a newbie to the classic car arena with my 'new' '67 coupe w/ a 302, so I will apologize in advance. Today, my car failed emissions with a 1033 measurement for Hydrocarbons at idle. Limit is 1000. Just missed. What's my quickest/easiest/cheapest course of action, keeping in mind that this car will only need to pass one time for as long as I own it? Carb adjustment? Although I cannot be sure, wires look new, so I would assume that plugs are not that old either.
Most injector cleaner I've seen is made from methanol, which is why it burned cleaner. But if you want a long-term solution, I'd install a Pertronix ignition with the coil as well. I have one in my '68 and stock points in my wife's '69 Corvette. It really burns my eyes to run the Corvette in the garage for more than a few seconds, while the Mustang burns MUCH cleaner, despite the fact it has a pair of Holley four barrels for carbs. I know you're looking for a quickie fix just to get it to pass for now, but swapping to a modern igniton will get you better mileage and easier starts as well.OK, looks like you got some decent answers so far. I think rbohm's suggestion should get you thru the "cheapest" as that's what you wanted to do.
ron67fb also says he's heard of the additives that are supposed to help get you thru as well so check that out since your that close to passing.
After you pass I would still take the direction of these other posts when you have time and tune the engine to optimum performance though.
Hope you guys have as sence of humor about the crazy nut making you motorheads look bad, just a joke. My GF says now the woman put two bottles of injector cleaner in her tank w/ the high octane and that's how she got thru.
next set your timing between 10 and 14 degrees. adjust your idle mixture to where you have the highest vacuum reading you can get. run the idle speed up to around 950 rpm.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?