Ok guys, First off, im new here...Just picked up a thirdgen camaro and i really like it! Specs: 1986***** Black 5.0l Carb z28 86000miles now to my problem... Got a smog check after I bought it, I had failed the Fuel Cap test, Fuel Leak test, and didnt pass hydrocarbons my numbers: 15mph:151 MAX:126 25mph:122 MAX:101 As you can see I barely failed that...I was told that had I ran the car for about 20 min prior to taking it in i would have passed it... ANYWAY, since i just got the car, i wanted to treat it right, so I went all out. here is everything I did: Engine clean/scrub spark plugs wires cap rotor air filter Fuel Cap thermostat + gasket new clamps on some of the hoses new battery terminals (they were taken on and off with pliers) and some engine cleaner in the fuel tank I then drove about 150 miles on it, and the engine light came one, so i went back to the mechanic and we found a fuel leak under the carb, so we fixed that, and it was idling a bit low so we fixed that...We also replaced the oxygen sensor to be safe. The next day, i take it to get smogged again. I pass the fuel cap test, pass fuel leak...pass EVERYTHING with flying colors, EXCEPT HYDROCARBONS... Now check out my numbers: 15mph:2118 MAX126 25mph:1370 MAX:101 I am now a "GROSS POLLUTER"!!!!!!! What on earth do you guys think happened?????????

I thought Carbs. were not available after early 1987 in Third Gens? Did you buy the car from a private party? If you did not sign off on the car as an as is with you being responsible, the previous owner is responsible to have the car pass smog.

Its probably TBI. First time I saw one I thought it was A carb setup, but now I know better.

If you have tbi, I wonder if you have an injector stuck open? I think excessive hydrocarbon is the result of running rich, or incomplete combustion. After writing this, it dawns on me that a dirty air cleaner could cause the same thing.

1986***

sorry guys!!!

Thats what i get for posting at 4:30 am!!

Check your initial timing, and also your vacuum hoses. Its possible during your upgrades that a hose didnt get put back in the right place.

I checked the hoses, all seem to be fine...

Is there an easy/cheap way to check the timing? im just learning mechanics and such (thats why i bought the car) so any help there would be appreciated.

Is that something i can get done at...say...pep boys?

I would not take the car to Pep Boys or any other "chain" shop. #1 They don't really have any system in place as far as I know, to rate mechanics or demonstrate that they have competent mechanics. #2. The last time a new car came out with a carburetor in California was probably sometime around 1986 or 1987. That is 22 years ago. A mechanic who is under 40 may have never seen a carb. That is also why you probably won't find a Chevy dealer with a mechanic who would be familiar with your car. Most dealer mechanics are too young to have seen or worked on a car with a carburetor.
#3 New cars are high tech. The computer control systems used by the various manufacturers are entirely different from each other. A shop that works on everything may see 50 different makes of car that have 50 different systems. In fact, the electrical system on a Chevy form the 1980's is completely different from a 2009 Chevy.

What you need is a Helm Manual. Those are the factory manuals for our cars. Go to www.helminc.com The service manual for your car is $75.00. You may be tempted to buy one of those $10.00-$20.00 books from an auto parts store, don't waste your money. Buy the real deal. If the manual you are looking at is not as thick as a Los Angeles telephone book, it won't have all of the info you need to work on your car. For about the price of one hour's labor or a little less froom your local Chevy dealer, you can get a manual that will tell you everything you need to know about working on your car. If you bought the car to learn to work on it, order the manual and start working on it.

On the efi cars, we neeed to unplug the ecm from the engine to disable the automatice timing adjustments the computer does to check the basic timing. On your car, I don't think the ecm does any timing adjustments, but I may be mistaken. If your ecm does timing adjustments to your distributor, there will be a brown wire with a plug near the firewall between the a/c unit and the distributor. If there is such a wire and plug, you need to unplug it to check your base timing. Normally on a carb engine, you need to just remove the vaccum hose from the vacuum advance mechanism on the carb, plug off the hose with a screw to keep form having a vaccuum leak, and then use a timing light to check your timing at idle. If the timing is off, you adjust it by loosening the clamping bolt at the base of the distributor and rotating the distributor until the timing is on the mark.

Hey thanks for your reply.

Yeah, i already bought the 20$ book at autozone, but what your describing sounds better. I do have a question though, will the manual walk you through things? or will it just tell you to do things?

Like for example, you say check the timing with a timing light, will the manual walk me through how to do that? or will it just say the same thing?

I know what a timing light is, and i know the basics of how to do it from asking my mechanic, but it would be cool to have a guide somewhere, no matter what it costs, to walk me through some of this stuff. This site has already been a MASSIVE help.

But back to the original question, would timing have the affect that this problem I have is causing? the massive polution?

Also, i think its important to point out that at this point i have more invested in the car then i actually payed for it, and i think im about to reach the actual value of the car, so im pretty desperate at this point....with that said, someone else told me to shove steel wool in my catalytic converter? do you think that will work if i take it out right after smog?

I'll try to answer this in a way that is helpful to you, but first you need to correct some of your thinking. Your last paragraph sounds like something a car salesman will tell you to get you to buy a new car! The resale value of the car has nothing to do with what you spend to fix it. You bought the car and have done nothing more than hired a mechanic to do a tune up and you have reached the resale value of it. If you have a used car that is more than 5 years old, that is a given. If you spend the money to buy a new car with a warranty and factor in the depreciation, you will have more invested in the car than it is worth before you drive off the dealer's lot. The automotive industry has historically set resale values of cars in order to convince people that they "need" new cars as soon as it is time to change the oil!

Forget steel wool in the cat. That is not a solution.

Go back to my second post. If you did not sign off on the car that you were buying a car "as is" that may or may not pass smog, but you would take responsibility to make it pass smog, the previous owner is responsible for getting it to pass smog. You should have had a smog certificate less than 90 days old on the day you took delivery of the car. You can't go back to the previous owner to make them pay for the work that you had done, but you can make them pay for the cost of getting it to pass.

You said you know what a timing light is, do you have one? Your $20.00 manual should tell you all that you need to know except how to use the timing light. How to use the timing light is included in the instruction manual that will come with the timing light. Since different cars have different locations for the timing marks, in fact there are two different locations for the timing marks in a Third Gen v8 depending on whether you have a carb or tbi which has it in one location or a tpi which put it in another location because the intake is in the way of the light if the marks are on top of the crank pulley. Therefore the timing light manufacturer will direct you to check your car's shop manual for instruction on how to set timing. Different timing lights might have different functions so the car manufacturers do not tell you how to use your timing light, they presume your timing light manufacturer will tell you how to use the light you buy.

Your hydrocarbon problem is the result of incomplete combustion. There are numerous problems that could cause incomplete combustion, but it falls into 4 basic areas. The engine is not getting enough air. It is getting too much fuel. The timing is off so that the spark does not occur at the point on the combustion cycle to allow all of the charge to burn before the exhaust valve opens. Your ignition is bad or a couple of plug wires are reversed, or you have a cylinder with low compression. Between your timing light manual and your car manual, you should have enough information to check and adjust your timing.

If you are not getting enough air in a car with a carburetor, you usually have a plugged air cleaner. Since the air cleaner sits directly on top of the carb with no hoses between, there really isn't anyplace else for a restriction to occur. Your new air cleaner should eliminate that problem.

Too much fuel getting in to a carbed car is a carb problem. It may need a rebuild. At idle it could be that someone turned the needle for the idle adjustment in too tight and destroyed the seat allowing too much fuel to flow at idle, but that should only result in problems at idle, not under load. The float in your carb is set to hold enough fuel in the float chamber to get enough fuel to the jets at wide open throttle with enough reserve for a good "pump shot" out of the accelerator pump. If the float does not shut off when fuel level is at the right level, the fuel pump will flood the engine.

If you have low compression, the engine will need a rebuild.

Finally, the state has programs for people with older cars that will let you spend up to $500.00 (I think that is the max) to get repairs done to pass smog at licensed smog shops. If you have any aftermarket equipment on the car, they will generally tell you to remove it and put it back to stock before they start on it and that cost is additional.

Thank you for taking the time to help me out...I REALLY appreciate it.

What i meant by the money I put in the car...when i bought it there was just a certain number price tag that i wanted to put in to get a working/legal car...and im about at that limit...basically i guess i was asking if its going to take a LOT more money, or just a little bit more.

I do not have a timing light, but will pick one up asap.

One other thing that i think is worth mentioning, as ive heard it from a few people...I went to get a smog almost immediately after putting in the new oxygen sensor...could this have been the problem???does the sensor need a break in period or adjustment time?

AS for timing, im going to check that as soon as i get a light...I am also going to check the spark plug wire position as well.

THank you again!

Before you blindly throw parts and money at a car you need to get to know Dyno Don. He could save you a lot of time, aggravation and money.