Every government agency "thinks" they are running the country!

 

It's actually the US Government as a whole.

A change in the emissions laws to retroactively affect older vehicles would quite literally
require an Act of Congress, I really doubt that would happen.

If you ever visit a big city in a country where they don't have *any* emissions controls on
their cars & factories, perhaps you'll better appreciate what our government does to help
protect the environment.

 

What device was used to eliminate backfiring on deceleration, ctubutis? I don't think my truck has anything like this, and that sounds like something useful I might want to add.

 

All I remember is that it's a device in the carb area, may have been a vacuum retard delay
valve or some such. I was trying to learn about and figure out what to do with my own truck
when I found a guy who was a Ford mechanic for 20-some years at his grandfather's
dealership during this time frame (70s-80s), the details this guy could tell me about my 25
yo truck just blew me away. He was a neighbor of my father until he moved to eastern
Colorado about a year ago.

 

I remember a "fuel cut solenoid" on a toyota I had years ago. It was an internal carb thing that shut off fuelflow when engine braking. I think it was more for fuel conservation or emissions thing than an anti backfire device. Louder exhaust will let you hear the normal backfiring on decel also.

 

Agreed - what I was imagining would be simply an EPA push for actual enforcment of the existing laws - the "original equipment must be on the vehicle" clause. All that would be required would be 1) to check the VIN for the date of manufacture, 2) make sure that matched the date on the emmissions diagram sticker under the hood, and then 3) quickly look to see if the main vacuum hoses, solenoids, etc. appeared to match the sticker diagram. If the answer to any of #1-3 above is no, then sorry, you fail the inspection.

I admit it isn't likely, but is possible in my paranoid mind at least. Such an inspection would take only minutes but might fail many older vehicles (e.g. DSII conversions).

 

Ford had the "de-cel" ( sp) valve used in the Pinto a few years back. To stop backfire under de-acceleration.

 

OIC. Some places are lots more strict than others, and I have no idea what the
consequences to the state are if they don't enforce the laws (kinda like the Fed will
hold back money destined for highway projects if the states didn't comply with the 55
MPH national speed limit).

 

There are a lot of laws all over that most people don't know about. In NY you are not allowed to modify the exhaust as it came from the factory. If it originally has single you can't put on duals or headers. When you leave your vehicle, the parking brake must be set and the vehicle locked. Some laws date back to the 1950's-60's and haven't been enforced in years nor repealed. Some things are ok for NY Inspection but, could result in a "moving violation" depending upon the law enforcement officer.

 

Tell me more about this valve, GLR. This sounds like a useful feature to have.

 

The problem is, many of these things aren't discrete components that can be selectively
installed & enabled as desired; they all work together as a system and there will be
dependencies on other components being installed & working for any particular action to
occur.

For example, the system will raise the engine idle speed when the engine gets warm, this is
to draw more air through the radiator. It does this by switching the dizzy vacuum source
from ported (switched) vacuum to manifold vacuum. To make this work, the engine needs
the two or three temperature-actuated vacuum control valves and the related plumbing.

Those same temperature-actuated valves allow for the EGR valve being activated only
when the engine is warmed up and not at idle.

Given the lack of computer technology back then, it amazes me how much Detroit was
able to accomplish using only temperature & vacuum.

 

Lots of carbs back in the day had a solenoid shutoff that would close the idle circuit when the throttle was abruptly closed or the key was off.

My carbureted 460 came with a dashpot that would not allow the throttle plate to slam shut, but rather closed it softly.
Much the same effect, fuel wasn't sucked in due to the vehicle driving the engine on overrun.

 

I think this valve was linked in with the dist vac advance (hey, it's been a while)

 

I understand what you are saying, ctubutis. When I converted my truck to Duraspark II and eliminated the feedback carburetor and engine computer, I went back and retrofitted the evaporative components to vent the gas tanks using a delay valve, restrictor, and ported vaccum switch. So I get what is needed to make these vacuum accessories work properly without a computer.

For example, I added a 220 degree thermal vacuum switch to the hole in the top of my goose neck. This switch has three ports and is tied into the vacuum advance. The middle port connects to the distributor, the top port to ported vacuum, and the bottom port to manifold vacuum. The vacuum advance works off of ported vacuum under normal operation. If the temperature climbs to 220 degrees, however, the switch only allows full manifold vacuum to come through, effectively raising the idle speed and water pump to help cool the engine. This circuit is not factory correct to my 1985 F150, but older Fords had this, and it works great!

And I agree, it is really amazing what Detroit engineers were able to accomplish before computers using engine coolant and vacuum switches!

 

You know what? I was cruising around RockAuto recently, and they did have a "vacuum advance delay valve" that I have never seen before. Is that what the purpose of that delay valve is?

Or is a "dash pot" the same as a decel valve?