A few months ago my inspection sticker was out of date, and foolishly I took it to the NJ state inspection. I failed, by having my emissions being over 100x the limit. I was told this is due to un-burned fuel. (I passed inspection later by going to a private mechanic)

before I go any further I will say that my exhaust system was replaced before I got the car, and it came with no cat converter, and this is definitely a reason my emissions are so bad.

But I was also wondering if my carburetor could be dumping too much fuel, and it not all getting burned, just because it seemed like my emission #'s were too high for it to just be the cat.

any ideas? just wondering, I have a few years before my next inspection thanks

 

Unburned fuel is usually an ignition problem. Can also be running too lean, which causes misfires and poor combustion. There are other causes but assuming the carb is rich and chasing it down as a rich problem can just make the problem worse unless you know for double damn sure it is rich. A full reading of your emissions readings is more telling than just a general description. Of course, it could be a mountain of other issues, but these are the usual suspects.

An very efficient-running engine can probably pass emissions sniffer testing even without a converter.

 

When did the car have a basic tuneup? Air filter, fuel filter, spark plugs, PCV? Have the plug wires ever been tested to see if you need new ones? Has the cap and rotor been checked? You should always start with the basics before blaming the carburetor.

 

If you can scan and post or transcribe the emissions readouts, that would help a lot.

 

Often, a spectacular emission test failure is caused by some kind of vacuum leak. Begin looking for bad hoses, leaking intake manifold, bad vacuum accessories. Put a vacuum gauge on the engine while it's running, and use some kind of clamp to gently squeeze off one vacuum hose at a time, to see if anything improves. Open a propane torch (don't light it) and spray around the intake manifold, and see if the idle speed increases when you are pointing it any particular where..
Over advanced timing at idle can mess up the emissions, as well. Full time vacuum advance can do that.
I don't bring my C3 to the NJ state inspection stations any more. The morons there generate too much clutch smoke. Twice (at two different stations, two years apart) they tried to drive my car with the parking brake fully engaged. I can't begin to tell you how unhappy I was......

 

I will say that not having a catalytic converter on a car, that was originally equipped with one, is an automatic fail in NJ. Normally the first thing they do, is look under the car with a mirror, and if the cat's gone, they fail you right there.

Beyond that, are you getting those emission level figures, from the testing facilities print out, or is that what the tester claimed? I learned long ago, that you cannot believe much of what they tell you at the inspection stations. It seems that some of their employees enjoy giving people incorrect info.

When I was in high school, I worked at a gas station, that was just across Cuthbert Blvd from the Cherry Hill NJ inspection station. Because we were so close, people would fail, and drive right in to see us.

I bet that 25% of the cars that we saw, had nothing wrong with them! Emissions, parking brakes and headlight adjustment, were the big three. We'd tell the owners to wait a couple days, and then go back (this was before garages were allowed to do NJ re-inspections). Without doing any repairs, they'd usually pass, the next time through.

I use to kid my boss, that he must be paying off someone at the inspection station, to fail cars.

That use to be part of the normal procedure, for the NJ inspection process. Before Christie got rid of safety testing, parking brakes had to be tested, and that was how they did it. After the regular brakes were tested, the inspector would apply the parking brake, and give the car some gas. If the car moved, you failed.

This was an ongoing joke with Corvette owners, as we all knew that the e-brakes on 63-82 Corvettes, never worked. The inspectors knew it too. If you got a good one, he would look over at you, smile and then try the brake, knowing full well that it wasn't likely to hold. Most would comment on it, and then let you slide,..... but not always.

 

Yea the inspection place gave me the print out, and I actually didnt even know there wasnt a cat, I had the car for maybe a month before it was inspected, and the previous owner only had it a year and didnt know much about anything (why I got it so cheap)

soon after a failed i took it to a private mechanic who passed me for a small fee.

I'll also be replacing all my sparkplugs and ignition wires soon and maybe that will give me some insight on not burning all the fuel

 

I found having a 3-way converter (helps with NOx emissions) was a big plus when I was getting inspected in Florida. My EGR had been welded shut and with it not reprocessing NOx, I had to have the good converter. Once Florida did away with inspections (all years), I went with a new 'cat back' system with headers, true duals and h-pipe. I still keep it tuned... FOR POWER!!!

 

Hey, you need to fix your lean situation but, why not get QQ plates and you will
never need to go to the inspection station again.

 

No, they weren't testing the emergency brake. They were just too stupid to release it! The inspectors kept revving the engine higher and higher. Smoke (burning clutch facing) was pouring out from under the car. Literally. Could. Not. Believe. It.
Nowadays, all they test is emissions. My godson has a late model Mustang with NO MUFFLERS. The inspectors interrogated the computer on his car. With no trouble codes stored, they passed it.

 

You need to be at least 25 to have historic plates, Im not 25

 

Mufflers aren't an emissions component; though you may fail some areas' inspections for noise violations.

I have had good luck with smog techs not wrecking the 78 but it makes me nervous as hell every time.

 

Post your emissions numbers. You can fail on CO and on HC, which have 2 completely different causes. Unburned fuel is not a carb problem -it's an ignition problem. But the numbers (if you post them) will tell the story.

Lack of a catalytic converter will change the numbers dramatically. Most cars with a converter will not pass emissions without one. A converter will take a massive-polluting car and make it a green-friendly thing that any hippie would love. Remove the converter (for whatever silly reason you think you have to do that), and you got yourself one heckuva' tuning problem on a car that needs to pass emissions.

Lars

 

Can't find the numbers right now, I have to go digging, but I know it was my CO levels
and I bought the car with the missing cat, eventually I'll put one in and it will probably make a dramatic change.
I also have a slightly high idle that I need to tune down

 

If CO is high and HC is good, simply lean it out a bit: The GM-recommended way to get the CO to pass without using a multi-gas analyzer was to adjust both idle mixture screws evenly until best quality idle is achieved (note that it was best quality idle - not neccessarily highest idle rpm). Then, screw both screws in evenly to obtain a 50 rpm drop. This was called "idle lean drop" in the GM Service Bulletins in the '70s, and would produce a good CO level for emissions. If it won't pass CO at this level, you're going to need the converter.

Lars

 

thanks, and 8-900 idle rpm is what I'm looking for right, I'm a tad over 1k now unless its been running for a while, then it will drop down a bit