passing emissions?

Ok.....
So if I reduced the timing to 0
leaned out the air flow screw as much as possible with the RPM's around 1000
and side gapped my plugs....
....would this drive my HC and CO numbers down to something more acceptable?

(currently my airflow screw is out 2 full turns)

Steve...
 
If it's out that far, it is definitely too rich at idle regardless of your points/ignition situation.

Your idle should be at +/- 750 in Drive for automatic and - uhhhh - 550 to 600 for standard trans.

Anyway, at idle in drive or neutral, screw the A/F mix screw in until the engine just starts to stumble. Then back it off slowly until the idle just starts to smooth out, then a quarter turn more.

If you have a vacuum gauge, connect it to a manifold vacuum port and back the screw off until you get the highest vacuum you can over 18*, then give it a quarter turn more. That will be your best idle. If you never get 18* or you never get a smooth idle, you have other problems.

A vacuum gauge is not expensive, maybe $20 to $30. It's an entry level tool. Next would be a dwell tach and then a timing light. The Pertronix One is only around $80 and it will make a big difference in your starting, fuel combustion and economy. If it is the difference between passing and not passing, I would do it. Especially since you don't have the DUI or the DS system in hand right now. You can salvage the DS. The DUI will definitely take all your milk money.
 
High hc is usually incomplete burn for one reason or another (like rich) isnt it?

Any idea what sort of coolant temps you are running? Its been a long time since I had to deal with that stuff but I do remember it being a problem for the guys running low temp stats and fixed fans. I remember seeing guys jamming cardboard in the radiator and racing up and down the street before getting in line for the test. There was a vacant lot about a block and a half down from the test site and there was always guys there with the hood up before and after the tests.

I remember having a chart that showed what each part of the test meant and what system was most like responsible for it. It was handy for figuring out what needed tweaking to pass. Without that its like throwing parts at a modern car without seeing what code the check engine light is complaining about. I looked for it in my old stuff but didnt see it. Seems like I had it jammed in my greasy mid sized rwd gm haynes manual since that was the first car I had that had issues passing. That is one of the few manuals I dont remember getting rid of and cant find.
 
Did you start out setting it up with the factory stock tune spec’s first? Maybe it would have eliminated some of the variables :hmmm:
 
Ok....so I went at it again tonight and I think I made some progress.

By screwing in the fast idle screw on the carb I was able to also drive in the air/fuel mixture screw.

I wound up w/ RPMs at 800, air/fuel screw out 3/4 of a turn and vacuum with a minor fluctuation between 17-18. Advance is still at 6 degrees.

This should reduce by HC & CO emissions correct?

Steve...

---and I'm really not sure of my coolant temp. I only have the stock L__H Temp Gauge and the sender must be on the blink because it never registers higher than just past the "L".
 
Got one of those infrared temp probe guns? If not the super scientific way is to see if you can hang on to the upper radiator hose. 120-150 range most people could hang on. If its around 200 (where it should be) most people would want to let go fairly quickly. Obviously you dont want to get your hand caught in the fan and you want to take some quick feels to make sure its not real hot before you try to grab it. Perhaps use a glove or a shop rag if you are not used to grabbing hot things.

Running at the proper temp is not going to magically solve all issues but it should help get em down a few points and perhaps with the other tweaks it will be enough.
 
:) A simple way to check your coolant temps is to buy a cooking thermometer.I got one for about $8.00 at IIRC Ace Hardware.Just start the engine and remove the rad cap,stick the
thermometer in the coolant.Them just wait a bit for the engine to warm up and it will give you the temp that your `stat is opening at and what the ultimate temp of the coolant is.
Leo
 
When I got into work this morning I grabbed hold of the upper radiator hose (after shutting the engine off). It was fairly hot and stung my hand. I could have hung on but it would have been uncomfortable.

On another note, after shutting her off I had a bit of dieseling and the idle sounded a touch high. I'm sure I can live with this until I test again on Saturday morning but should I make any further adjustments? or go as is?

Thanks again for all the advice.

Steve....
 
Sounds like you have to be in the ballpark temp wise.

For the dieseling if its an auto just leave it in gear when you turn the key off, the load of the transmission will kill it right away, just remember to put it in park before you take your foot off the brake.
 
***Update***

After side gapping my plugs and running with the following specs:

RPMs at 800, air/fuel screw out 3/4 of a turn and vacuum with a minor fluctuation between 17-18. Advance is still at 6 degrees.

I almost passed!

My CO is currently at 4.73 and needs to be at 3.09 in order to pass.

Any advice on what I should try and adjust first?

Steve....
 
Well my uncle is pretty good with a wrench so he would always fix my grandmothers car and one trick he had to help it through emission is he would add a bunch of alcohol to the tank. I don't know if you have access to E85 or other alcohol racing fuels but it might help. And yes the alcohol isn't so great for the fuel system but my uncles policy was that your only doing it once in a blue moon. Hope u get here through. Thats really rough that they make you do emissions for that old of a car
 
Yes and no.
I adjusted the idle up a wee bit, put the air flow screw in a wee bit, put the advance back to 0 degrees and put 15L of 92 octane along with 1L of Methyl Hydrate and has the car tested again last weekend. The end result was almost the exact same numbers.

Still failing on CO. Currently at 4.02 and needs to be at 3.09 in order to pass.

So I bit the bullet and placed an order for a DUI with Mike this morning.

I'm looking forward to seeing the difference...

Steve....
 
Dude, I was going to say something about electronic ignition. It burns so much more of the fuel. You'll love the result. More pep, more economy, better starting. Really. It's so good it just HAS to improve the emissions score.
 
I fully agree.

I used to drive a 71 Mach 1 with a 351C in it.
When I changed it over to a DSII it made a dramatic difference.

Once its installed I'll report back on the results...
 
Actually, I was going to say that you should install a Pertronix just to get it passed. It would be like 90 loonies or so for Ptx I. However, if you do the dooey (DUI), you are a real man.
 
Sounds like you may have idle RPM up too high still! :shock: I usually will set them from 50 to 100 RPM lower than factory easy on a used engine with looser clearances. Too high of an idle and you bypass the carbs idel circuit all together!
 
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