I’m going to remain on the fence until some actual numbers are posted along with info about which state this is in, how this test is performed, etc.
“It makes you wonder why people didn’t notice it all the time prior to the 80s.”
Maybe all the tobacco smoke masked it. ;o)
To answer some questions:
Yes, at the time, the Explorer was only a couple of years old. All vehicles had been warmed up. We drove the explorer across town to get the 2 trucks on lunch period that had ended about 10 minutes before. 2 trips of 4 miles each and a 2 mile drive back on each of the trucks.
I did not think about the lean condition of the carb of the '59 until now. I had just rebuilt that carb, rejetted it to a smaller jet. If my memory serves me right, the mixture screws were set at about 1 turn out from lightly seated…
As far as the '65 is concerned; It was driven about 20 miles before tested. We compared the test results of the '65 to the known standards of the EQUIVALENT new vehicle.
I also realize, I did not include the fact that I’m in Idaho now and our DEQ sets different standards than, say, L.A. or New York. Probably not as strict but still meets federal requirements. The town I live in just this year, has been required to submit to emissions (have to drive to Boise to get it though)…
Again, I’m not looking to start a major debate, just some answers on WHY this happened. I know this is not “normal.”
Thanks. Excellent point about when the testing was done. It would also be interesting to see the actual readings, to see how they compare to current requirements.
A big enough exhaust leak will pass the heck out of emissions. Once I fixed mine it still passed but it was really close. Now, how about a 73 Maverick with a 302?
I think the 28 grain truck would do well with the low compression engine and small carb. Without the actual readings we don’t know what was wrong with the 91 Explorer. It should have had zero ppm of CO and about 20 ppm of hydrocarbons; about the same as the air in the tires.
They put a 302 in a Maverick? I never saw a Maverick with any redeeming values, that could be my first! You are a smart guy, My thought is a catalytic converter does not treat CO, or 02, and is meant more for hydrocarbons and particulate matter, so low CO and 02 readings are of no significance.
Try adjusting the CO on a carb while watching the meter on the emissions tester when you have the sniffer post cat. You will be turning the adjustment screws and saying to yourself “why is the CO not changing I am moving the mixture screws”?
When making mixture adjustments you want to make sure the air pump (if equipped) is disabled because this will distort your end result even more than the cat. but the needles (even CO) get real lazy in responding when you are taking your sample post cat.
We are getting a bit off the path from the OP’s claim that emissions gear hurts rather than helps. The OP used his older car examples to support his claim which I feel have been dealt with properly. The idea that emission equipment hurts rather than helps is a very hard one to convince people that don’t understand the equipment that they are wrong. I think this difficulty came about because of all the problems that early emissions gear caused. This era created a mindset that is almost impossible to change.
In short, the bad old days of early emissions technology have created beliefs that cannot be"put to rest" so to speak by technical explaination. There have been too many mechanics simply remove the gear because they did not understand it and a very willing customer to accept this mechanics apprasial of this gear. We will never get out from under from the damage done by these early emission days.
I trust, waterboy, that you meant CO2. O2 is just diatomic oxygen, perfectly harmless unless it captures another oxygen atom and becomes triatomic…which is ozone. The air we breath contains lots of O2.
Anyway, while the primary function of the converter is to reduce nitrogen oxides, the oxygen atoms that the platinum-palladium strip from the nitrogen oxides are picked up by the carbon monoxide molecules, making them CO2. This is often called the “second burn”. It does have a secondary reducing effect on carbon monoxide.
It has no function in reducing particulates if everything is working correctly. Particulate deposition is actually what reduces the effectiveness of the converter by coating the catalyst, and is not a desired thing. Only when nitrogen oxide molecules can come directly into contact with the catalyst does the converter function properly.
Oldschool, you have a good point. Early emissions reduction efforts were very crude, primarily consisting of running the cylinders hotter and leaner, combined with cat converters to clean up one of the results of hotter cylinders and odd attempts like the air pump you mentioned, and came with limited results and some bad side effects. It really wasn’t until microchips made onboard computers a reality that engineers were able to accurately control fuel injection systems, thus enabling nice high-pressure fuel spray and accurate metering that significant progress became possible. Then making fuel control even more precise via multiport injection became another huge leap, again made pssible by the evolution of onboard computers. I’ve made the argument before that TBI and then multiport injection should be considered emissions systems as much as any other system.
The next big step is direct injection. It operates with even higher pressure, injects the fuel directly into the chambers, and even pulsates the squirts to get delivery to happen at optimum moments in the compression and power strokes. It’s even believed now that engines at full operating temp can be restarted immediately by simply spraying the injectors into whatever cylinder is at the optimum point to do so having it ignite much like a diesel. That theoretically could make more feisable the idea of routinely shutting off engines at “idle” and restarting them when you hit the pedal. The engine wouldn’t have to go through the whole starter-motor restart. We’ll see how well that works out.
Why can’t CO be adjusted on a carbureted engine? A cut and paste for a Carter-Weber. (used on some models of Subaru for example)
Adjusting idle rpm and CO%
Before:
Check valve clearance, ignition timing and sparkplug gap. Warm the engine up to operating temperature. Remove hose of carter ventilation from header cover.
Procedure:
Use throttle screw 3 (figure 1) to adjust idle to 950 (? 50) rpm
Adjust mixture screws 1 and 2 to raise rpm as much as possible
After every raise re-adjust to 950 rpm using screw 3
Now turn screws 1 and 2 in one at a time by equal amounts, to lower revs by 25 rpm
CO reading should now be 1 - 2%, if not repeat last step
Adjust to 950 (? 50) rpm using screw 3
OK4450 We (I) am not saying you can’t adjust the CO on a carbureted engine, what part of my post(s) leads you to feel this way?
What I am saying is that you must disable the air injection pump (if any, and simply pinching the hose is enough, surely you have done this) and to sniff pre cat. if any is installed.
My "toy’ that I just parted with 1965 GMC that I put a 330Hp small block and a turbo 350 in) had an Edlebrock 600 cfm 4bbl on it and once this engine was set at 3% CO I had under 300ppm HC and did not adjust it again for probably 3 years. I ran out of a place to park a truck I never drove and it was bad with no heat and no AC. Drove it from Tucson to Milwaukee more than once though. My wife (now-ex) simply hated that truck and was not at all happy with the money I spent on it.
Do you know if these engines you cite idled nice at 1%CO? or did they really like being set closer too 2%?
On one model BMW (early 318 with O2 sensor) we set CO by measuring millivolts at a sensor. I want to say it was the O2 sensor but that does not sound right with a millivolt adjustment. The cars were CIS cars also. Remember that little 3mm allen screw for CIS CO adjustment? that adjustment was the first to go when the EPA started taking away adjustment possibilites.
“Anyway, while the primary function of the converter is to reduce nitrogen oxides”…
Not…When the catalytic converter first appeared in 1975, it’s PRIMARY purpose was to reduce Carbon Monoxide (CO) which was poisoning many American cities…It also did a good job of reducing unburned hydrocarbons (HC). NOx was not even on the radar as far as testing went…The primary device to control NOx, then and now, is the EGR valve…
A properly running modern car is a 1000 times cleaner than any 1959 model…An exhaust gas analyzer is useless to “Test” a modern vehicle. The machine would just read zero for both CO and HC…Modern cars are judged on a grams per mile basis, not a percentage of exhaust gas volume…That’s why they are tested on a dyno.
When computer controlled fuel injection became standard in the late 1980’s, the air in Americas large cities enjoyed dramatic improvements in quality. Emissions TESTING has never done anything other than suck $35 out of motorists pockets every year or two…
The diesel truck craze has caused some back-sliding in urban air quality…
At 1% CO you are a 1000 times dirtier than a new car, which is allowed something like 10 grams per mile, which converts to .001% CO… It takes a 1000 new Ford Fusions to equal the emissions of a perfectly tuned 1959 Ford Fairlane…It’s as simple as that…
If I misread your post (entirely likely) then I apologize up front. Based on the vehicles given by the OP my opinion was that the CO could be a wash at idle speeds. Once the throttle is floored things can change a bunch, and probably did.
As far as I know most dealers don’t have their regular mechanics PDI their cars but a couple I worked for actually did. With the SAABs we were allowed 5 hours PDI time. It was a thorough process (gravy money too!) and involved sticking the infra-red probe in the tailpipe along with adjusting the CO, etc.
Every single SAAB as per the EPA and SAAB arrived with the CO set at around .75 and every one of those cars had a slightly rough idle, which was especially irritating on an automatic transmission car. Since the major issue was trying to sell a high end car that had a slightly rough idle there was only one thing to do; we set the CO on every one of them at 1.25% and this smoothed them right out. Of course this was a blatant violation of EPA regulations but since no one had a better answer that was the SOP.
No, the engines did not idle nice at 1% either. Better, but still not acceptable on a high dollar new car.
Back in the EEC controlled Subaru carburetor days we also violated the law a bit there too. The manual trans cars were prone to a 2nd gear balk on acceleration which led to many customer complaints and zero help from Subaru of America. What we did in this case is remove the carburetor top and reamed the accelerator pump discharge nozzle out a few thousandths of an inch with jewelers drill bits and a hand arbor. It worked, all legalities aside.
I saw the newspaper article in the 90’s, where a automotive teacher did the same thing with an old car from the 20’s, and it beat the current standards. Surprised the heck out of him, and it was tuned by ear.
I am answering here before reading because of the offensive unfounded remark here.
The reason we had to go to smog junk on cars is because we have a need for much lighter motors, and more fuel efficiency. Short strokes are more subject to outputting nasty stuff, than the old, inefficient, long stroke motors with time to burn it all up.
I’ll never forget the time our dealership received a new shipment of AMC vehicles. None of them passed the smog test. Factory rep was notified ASAP.
I would like to see the paperwork on these vehicles mentioned by the OP. Sure, you could probably tweak the mixture and/or timing,but the vehicles wouldn’t run well on the road.
How do you adjust the mixture on that 28 Chevy, put a smaller wick in the carb? I nailed this one the moment it was posted, I notice we have not heard back from the OP,“running like a scallded dog is he”
I disagree. Platinum Palladium does not directly affect carbon monoxide. It directly reduces nitrogen oxides by stripping the oxygen from the mitrogen. Nitrogen oxides, one of the elements regulated in the original Clean Air and Water Act, became a problem when cylinder temperatures were raised to reduce carbon monoxide and unburned hydrocarbons. Nitrogen oxides are a byproduct of increased cylinder temperatures. Directing a bit of inert exhaust gas to displace a bit of oxygen and reduce cyliner temps under load was an additional NOx control mechanism, creating a “two pronged” approach: reduce its production in addition to scrubbing it from the exhaust.
NOx was “on the radar” right from the start. It’s in the original “Act”.
I would also respectfully disagree that an exhaust gas analyzer is ineffective to measure emissions on modern cars, especially when done on a dyno setup. In fact, it’s still used in many areas and we get posts here often about cars that have failed using an emissions analyzer. And I definitely think it’s a better test than an OBD download, which I think is a joke. I understand is making this statement that an emissions analyzer does not check for EVAP system problems, but I think thst whole aspect of emissions control is out of control and ineffective in having any real impact anyway. Perhaps that whole subject is something for another thread.
I believe that emissions testing originally did help, but I also believe that at this point continuing to tighten testing requirements is a nonproductive misapplication of funding. The requirements on manufacturers, if kept as they currently are and testing (especially OBD downloads) were completely discontinued, would still result IMHO in emissions continuing to go down. Constantly tightening requirements at this point yields no benefits other than a welfare program for dishonest shops. The money spent chasing that last particle of pollutant, and especially that last hydrocarbon molecule (think: EVAP systems) would, IMHO, be much better spent enacting diesel engine emission requirements. That, in my opinion, is long since due. Or perhaps the money would even be better spent in the development of a nationwide EV recharging system. Perhaps with Tesla having proved the viability of the techmology for a daily driver, it’s time to invest in promoting a total conversion.
VW Bug is a baaaaad example. They were tuned especially rich due to being air cooled -- the fuel did a small amount of cooling, and it was particularly important that they never leaned out under any load or conditions since there was after all no water jacket to cool down localized hot spots in the design.
Anyway, I believe it. I'm sure as a collector of older cars, the owner of the '59 and the '28 had given them a nice tuneup (adjust the mixture screws and all that good stuff) which most owners of carbureted cars tended to neglect to do. These limits of 250PPM or higher are just a limit so it'd catch cars that are way out of tune, it's not the level they'd typically run at.
I had a 1985 Celebrity -- admittedly, this had throttle body fuel injection, but when I tested in 2002 (I thought there'd be smog tests in Seattle where my sister was taking it) it had 140,000 miles, all original (most relevantly, original cat...) and it read 60PPM HC and 0.09% CO. The smog tester read 6PPM before the car was even driven in (just from all the gassy rags sitting around in the shop.) This would have it just pass smog for a 2007 California car.
Regarding emissions crap -- really most of what I'd call crap was on the 80's vehicles, layer after layer of vacuum operated components sometimes fighting each other (really, I saw a diagram of one 80s model that had a vacuum advance, then added a vacuum retard that fought the advance, then the year after added a *secondary* vacuum advance to fight the vacuum retard in some condition.. 3 units fighting to control the amount of advance alone.) Here's a COMPLETE list of what was on my 85 celebrity.
EGR valve (lowered NOx), PCV valve (sucks in the crankcase fumes instead of venting them to air), cat, and smog pump (clean the exhaust further), and the fuel vapor canister. Oh, it did have a thing on the air intake (a "thermac") to make it suck hot air to warm up the air intake faster, that was kind of crap considering it was already fuel injected. That's it for true emissions controls.
The MAP (manifold absolute pressure) sensor measures vaccum to know engine load and so how much fuel to put in (instead of venturis and metering rods in the carb). Some cars instead had a MAF (Mass airflow) to directly measure airflow. TPS (throttle position sensor) replaces the accelerator pump, it gives a squirt of fuel if you snap the throttle. The temperature sensor replaces the choke. The idle air control valve is this plunger that blocks or unblocks an air passage to control idle speed, and finally the O2 sensor essentially acts to trim your mixture for you, instead of having to tweak the mixture screws periodically. Finally, there's the injector sitting there above the throttle that acts on all this to squirt in fuel. This *sounds* more complicated than a carb but keep in mind the carb actually has a lot of components too -- a choke, accelerator pump, mixture screws, jets, venturis, fuel float, etc.
My 2000 Buick, that's all *IT* has on it too (other than having six injectors instead of one). Well, besides having basically a black box with spark plug wires going to it instead of a distributor. (It also has *both* MAP and MAF, because the computer can compare the values to automatically detect vacuum leaks.) Some car companies have been overcomplicating things, but if they are smart with their fuel injection it actually makes things nice and simple.
I had a 1972 Fleetwood (essentially pre-emissions, it only had a PCV valve and vapor canister) and it looked real clean under the hood. The thing is, my 2000 Regal does too -- the 3.8 itself is pretty shoehorned in, but it's got a clean look, there's no mass of smog equipment and hoses under there by a long shot.“Oh, it did have a thing on the air intake (a “thermac”) to make it suck hot air to warm up the air intake faster, that was kind of crap considering it was already fuel injected.”
That’s because throttle body fuel injection is similar to a carburetor in that the fuel has to travel considerable distance down the intake manifold where it can condense back to liquid and cling to the manifold walls if the air and manifold are too cold.
The enrichment mechanisms on the carb. are carried out electronically in the TBI system.
Moving the injector(s) up next to the intake valve greatly simplifies the job of fuel/air control by removing a complex and variable delay element in the control loop.