I need to pass the emissions test with my 72 F-250. It has a 2 bbl and a 352, and it runs smoothly. But I want to make sure the test is a lock, so does anybody have any suggstions/experience/advice about this?
I live in Colorado, where 81 and older vehicles take a different test than newer cars, but it's still stringant.
BDV

 

I am in California, so things are different for sure.

What are they testing for?

Here for example the smog equimpent has to be visually present and in good shape. (no rotten vacuum lines)

There is an EGR test (pulling a vac. on it, I think)

And there is a measurement at the tailpipe. Some counties it is on a dyno, on others it is in idle at diff. rpm.

So, in case things are similar in Colorado the preparation is quite easy. You want to have your smog equipment all there. I think EGR wasn't even on cars in 72, correct? That will make it more easy then! PCV will be probably it.

For the pipe gas test it is important thta you have fresh gas in the tank. So if you don't drive your truck much, take it to work for a week before or on a few long trips to get all the old gas out. Fill it up and drive some more. Also make sure that the truck is warmed up when you bring it to the station, in case it is just around the corner.

HTH. I can make more educated guesses if you tell me more about the CO smog test in your county.

George

 

If it runs smoothly then it's probably too rich.

Make sure you have all the stuff to pass the visual, PCV, vacuum advance, heat riser, vapor canister, intact exhaust. Set the timing to factory spec, they check it. Install a new air filter and lean out the mixture screws until the idle speed drops about 50 rpm then set the speed to spec.

If you have a lot of blow-by it will fail HC. A fresh oil change helps along with some ring seal in a can, maybe two cans.

If they use a dyno, air up your rear tires to the max stated on the sidewall for less rolling resistance. Have the engine nice and warmed-up for the test.

Good luck!

Barry

 

I have a 67 with a 352 and 2 brl carb. For the California inspections when I had to do them a few years back, I retarded the distributor timing 2 degrees from what the book called for. Also I adjusted the carb using a vacuum gauge to obtain the highest vacuum with the engine running. (Make sure your throttle adjustment screw on the driver side of the carb is backed off when adjusting the idle.) Once each screw is separately adjusted to obtain the highest vacuum, for smog inspection only I turned in (tighten) each screw about 1/4 turn. This insures the low emissions are not too high. Advice about a warmed up engine, good gas and even clean engine oil can help especially if you think you are borderline.
When inspection is over I immediately drove home and advanced the engine timimg and opened the idle screws 1/4 turn.

Hope this helps. I'm sure others can add more.

 

Aside from the visuals, fresh spark plugs, cap, rotor,and wires. Fresh oil change and a functional PCV valve- Don't forget the air and fuel filters. Then sniff your tailpipe after you get it hot. If it smells rich, lean it out. Set the mixture lean to the point that when you sniff it, your sinuses tingle just a little bit like you're going to sneeze. Sounds funny, I know. If it pops through the carb, richen it up a 1/4 turn.

Good Luck-

Joe

 

I bought a truck that passed cause of
a blown exh manifold gasket. THis
test included idle and a dyno test. But
air care is a joke in Canada.


Fe power

 

The beautiful thing about emissions in Colorado is that there isn't an inspection on 81 and older, just a smog test. They only lift the hood to attach the tachometer. You could have absolutely nothing but an engine in there and they won't say anything.
I have been told that my truck smells like it runs rich, but it doesn't smoke or have black crap on the tip of the tailpipe. I dunno, I am so used to owning computer controlled F.I. I wouldn't know the difference.
I have new oil, and I ran a full tank of gas through it already, so I think that's OK. I will be changing the plugs soon; that's the only part of the ignition system that's not brand new. I don't think it has alot of blow-by, either. It is a really strong motor.
Is it safe to add Everclear to the tank and run it, or do these engines run too hot for that? My brother did that to an ugly, smoking, nasty Datsun and it passed in a breeze. I have also heard that ATF works good too. Any insight?
BDV

 

67 F-100, 352, 4 spd

I failed the first time this year but sailed through on number two. I did most of the stuff indicated in other posts and also added a gallon of alcohol. I won't hurt to pray and lead a good life, at least for a few days before the test.
jor

 

I made a suggestion of adding alcohol in a previous post and then partially retracted it because of a small chance it would create further work.

Here is an answer I'd feel confident listing the first time out:

Adding a gallon of denatured alcohol shouldn't *seriously* hurt anything. It does not burn hotter. It will give the effect of leaning out the mixture (helping your emissions) and boost your octane (increasing its resistance to knock).

But one caveat is that if you already have a big slug of water in your tank it won't mix properly and you'll wind up with an alcohol water mixture at the bottom of your tank that you'll have to drain out. Of course once the water is out you should be fine.

Then, another warning... the ethanol is a pretty good solvent and may loosen rust from your tank and wind up in the fuel filter. Once the rust is cleaned out, it should be ok. And if your carb gaskets or fuel hoses are on on the verge of failing, the alcohol may be enough to push them over the edge. But a carb kit is $25 or less and hoses are under $5.

These bad things probably won't happen, I just wanted to let you know there is a *small* chance. They've marketed gasohol (10% ethanol in gasoline) in the midwest for years and have had few problems and California has had it in pockets for a while and is about to get it statewide, too.

Good luck!
Tell us how it goes.

--Matt




1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Some day hope to shorten to a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

 

Colorado runs Ethanol in the 7 county Denver metro, Fort Collins, and Colorado Springs.
I found out another thing about 81 and older emissions in Colorado: if you can prove that you spent $100 trying to get it to pass, they just give you the sticker. I have already spent $80 on things that could be "interpreted" as trying to get it to pass, and I kept my receipts.
I don't think I will have too much of a problem getting the sticker now, and I think it will pass anyway. I have a month and a half to work it out before I have to get the test.
Thanks for your help!
BDV