Hey folks,

Last month while visiting home in NS, Canada I took possession of my fathers 72 AMC Ambassador SST with a 360 and once again made the 1100 mile drive down to Delaware where we live. Those of you who remember, I did this trip with our stang with about 50 road miles out of the garage back in 2010. Happy to say we had no real issues this trip either!

Anyways.. took it into the DMV today to get inspected & registered and it failed the emissions test. For CO% the limit is 6.00 and I was at 7.7. For HC(PPM) the limit is 600 and I was way over at 1535. This was an Idle Test. Current rpms at idle is about 650.

Busy for a few days before I get some time to dig in to see if I can correct this however I've never had to deal with emissions before. Any pointers or tips would be greatly appreciated!


I do plan the following..

• Replacing the spark plugs and wires
• Changing the oil filter & oil (15/40 Rotella T is all he has ever used in it)
• Changing the air filter
• Leaning out the Carb (Edelbrock 650) after I mark its current position.

Its got an aftermarket HEI distributor which had the ignition module die the morning after we got back. Easy fix and replaced the module and coil at the same time. Wife sat there laughing at me giggling that we drove 1100 miles without issue to park over night in our driveway to have the car die.. I had to laugh as well.


Thats my plan for now. Again, any suggestions would be appreciated. I know its not a mustang but V8s and emissions are pretty much the same. Also.. I've seen CO devices but haven't found any reasonably priced HC measuring devices in the backyard/home toolguys price range.. Do any exist? I'm told Delaware DMV doesn't like to be used as an emissions test tool with repeated failures on the older cars.

Thanks

A quick pic of the new addition... She's a land yacht for sure at 18' long but beautiful to drive.

 

Move out of a state that requires smogging a 72?

Chances are once you lean the idle out the HC and CO will both resolve. HC is typically too rich, but can also be a partial misfire condition (plugs and wires are a common culprit), and CO is an aberrant that's produced from "non-ideal" combustion; so if you resolve the combustion issue (probably too rich in this case) then the CO will likely resolve.

You could also try bumping the idle up a bit to where the engine runs a tad more efficiently.

Honestly though, smog testing a carb'd car at idle is pretty stupid. What you need to get it to run well and what you need to pass emissions are 2 separate things. Not that the people making the rules understand that.

 

hello;

ok, i would put in valvoline vr-1 racing oil, not rotella. the rotella your dad used to use is not even close to the new and "improved" more environmentally friendly stuff. i would consider using straight 40 because if the rings are worn, less will get by. run lighter oil after.

if you don't need a functioning pcv valve for the test then plug it. it sends crankase hc's back into the engine

tell us what your idle timing is. the lower the better. if it is too high it will never, ever, ever, pass, lol. if they do not check the timing, i would try 4 degrees btdc. if they do check it, some states allow a few degree variance so run it on the low side of stock in this case. if your engine runs bad like this, it likely either has a high perf cam and/or your timing chain is excessively stretched in which case you might need to bump it up a little.

as 67 mustang mentioned, a slightly higher idle will help also.

set your fuel mix screws to a slightly but not excessively lean position. too lean will cause a lean miss and it it misses once, it may fail. set mix screws with engine hot.

if your car is running below 195 degrees, install a 192 - 195 thermostat. you want it hot when you get there.


i learned how to drive in a 66 rambler rebel sst, lol.

also had a 66 rambler rouge factory 4 speed with the mighty "typhoon" engine, wow...

 

Why is this car not exempt from this?

 

there are some pretty cool ideas right there :-) I wouldn't even have thought of half of them!

 

That is a sweet ride by they way.

 

Thanks for the extra info and tips. Moving isn't an option. Many states still require smog tests on early 70s cars. Delaware requires the test on everything from 68 onwards. The inspection on our 67 consisted of driving up and having the car adored. No lights, horn, wipers, etc.

Barnett.. I was parked beside a 66 Rambler a couple weeks ago at a show. Owner said he had picked it up from a Salvation Army auction for $2500! It wasn't a trailer queen but it was a very nice car and dependable from what he was telling me.

Txcoupe.. Thanks. I've always liked it and happy I got it. My 4 year kid son lives it and enjoys going to preschool everyday in it. It's mostly original with the exception of the wheels and the interior had dry rot so we replaced it last year.