Community Forums

AZ_Ron · 03-24-2007, 07:29 PM

Hi All.. we took out New To Us 1984 Rockwood Class A through Emission today and she failed...
I'm pretty handy with cars and such, but don't know emissions much at all...
Here's what the readings were... if anyone can offer some insight on what I need to check out tomorrow, I'd be most grateful...

Loaded STD Result Idle STD Result
HC 100 300 Pass 1584 300 Fail
CO 0.13 3.00 Pass 0.14 4.00 Pass

Everything is AWESOME, except HC's at Idle...
She felt like she was running rough, maybe had a miss... At this point, I'm figuring on pulling all the plugs and seeing if I have one or two fouled. Make sure I don't have any burned plug wires, check the cap and rotor, etc... Any other thoughts??

Thanks all!!

Ron & Ember

AZ_Ron · 03-24-2007, 07:29 PM

Hi All.. we took out New To Us 1984 Rockwood Class A through Emission today and she failed...
I'm pretty handy with cars and such, but don't know emissions much at all...
Here's what the readings were... if anyone can offer some insight on what I need to check out tomorrow, I'd be most grateful...

Loaded STD Result Idle STD Result
HC 100 300 Pass 1584 300 Fail
CO 0.13 3.00 Pass 0.14 4.00 Pass

Everything is AWESOME, except HC's at Idle...
She felt like she was running rough, maybe had a miss... At this point, I'm figuring on pulling all the plugs and seeing if I have one or two fouled. Make sure I don't have any burned plug wires, check the cap and rotor, etc... Any other thoughts??

Thanks all!!

Ron & Ember

"007" · 03-25-2007, 08:21 AM

Welcome AZ-Ron to irv2 and the Vintage forum

You sound like your on the right track new plugs and wires. Could be distrubiter cap and points.
I will put your question down in forum below may have some direct answers for you.
Enjoy the forums and do post often.

GaryKD · 03-25-2007, 03:55 PM

Ron,
You are on the right track. Instead of just pulling and inspecting, consider replacing the plugs, wires, distributor cap and rotor. If I remember correctly the points are electronic, but if they are still mechanical, replace them too. Also, put the correct amount of fuel system cleaner in the fuel tank. Drive it 30 miles or so to get the chemicals moving through the system. Lastly, there is octane booster chemicals you can put in the fuel tank. Add the correct amount for the fuel in the tank. Try a reinspection. If she fails again, it is off the the carburator shop for you.

Carburators were about the only mechanical part
of an engine I did not get along with. While I understood what all the parts did, I was never able to aquire the skill to make all of them work together. For carb problems, I bought my way out of the problem.

Glen Taylor Jr. · 03-25-2007, 07:01 PM

I had a 84 chevy citation. Was had to pass smog. I used C R C pass or don't pay. Put my nic ox. way down. Hard to get but I passed twice with it. About $8.00 a bottle.Follow what it says on bottle.

GM Tech · 03-26-2007, 03:36 AM

When i got to work this morning I pulled out my emmission test books (we dodn't have emmission test in this area)to refamilliarize the reasons for failing. HC is unburned fuel going out the exhaust as the result of incomplete combuxtion. anything that causes a cylinder to misfire (abnormal combustion) will result in a high HC reading. It could be the result of being too rich or too lean fuel mixture, ignition problems or mechanical problems.

dieselclacker · 03-26-2007, 07:24 AM

Az_Ron, HC (Hydrocarbons) indicate unburned fuel mixture. CO (Carbon Monoxide) is indicator of burned fuel. Carburetor is OK indicated by passed CO readings. Look for a bad plug wire, or probably a worn or to wide of a gap in one or more plugs. If this is not the case, worse case, would be incomplete combustion due to low compression, burned valve etc. I have had a couple of 454's, and have some experience with them, all your indications are bad plugs. Hope so anyway

Dieselclacker

AZ_Ron · 03-26-2007, 12:46 PM

Thanks guys... here's an update...
I replaced the cap, rotor and plugs (Have nice 8.5mm wires with ceramic/porcelain boots!)
I used AC platinum plugs, gapped to the recommended .035.
Distributor is a GM HEI.
I believe I found and fixed a vacuum leak going to the choke vac diaphram on the left front of the carb. Took her back through, failed again.
All numbers but HC's at idle were virtually identical, but the HC's at idle dropped about 500 points, to 1076 from 1584.
Wondering if there is another vacuum leak?
A buddy of mine who I consider a wiz the this kind of stuff is going to stop by sometime this week and see if he can find something I'm missing.
Made a nice move in the right direction, but still a ways to go.
Thanks for all the suggestions guys!

Ron

Max Hubrich · 04-05-2007, 02:44 AM

Register your rig in Montana-- no vehicle inspection law. Its your second home then.

Max H

DirtyDogg · 04-10-2007, 04:19 AM

Timing.Did the right thing on the rest though.Put a timing light to it.

Lynn and debbie · 04-12-2007, 11:13 PM

Hopefully youve got it fixed by now. If not you need to consider your catalytic converter. If you have been running with high HC for very long there is a good chance the cat is shot.
Good luck
Lynn

J Walker · 04-13-2007, 04:06 AM

Did you fully warm up the engine before the inspection? I found that it necessary to do that on older vehicles and it makes a huge difference. I got where I would warm my old car up and even change the oil just to give it every chance and I passed. Without warming it up no way.

Wallaby Dan · 04-13-2007, 03:55 PM

J Walker is right. Warming up the engine real good will help as the converter has to get Hot in order to make it burn correctly. I have friends who run the coach over 50 miles and gets it up to highway speeds first then they go thru the emissions and pass, No matter how old the coach is.
Good luck and let us know how it goes,Capt.