Changes in smog equipment over 3X8 history

While I cannot give you the whole story, one part is that is the late qv/3.2 they went to a single cat from the QV's previous dual cat in the US/Ch cars to add a single pre-cat O2 sensor enabling lambda feedback on the US/CH K-Jetronic by means of a frequency valve modifying the control pressure. The Euro market qv/3.2 soldiered on with the original non-lambda system.
The QV/3.2 US cars also did not have a pump but rather air injection at the head exhaust port driven by exhaust pulsing and enabled by check valves.

Some one else may add or correct me,but this is what I remember.

 

The CH (Swiss Market) 328's do not have a frequency valve (and of course no O2 sensor because of that). They do have the thermocouple and associated circuitry to activate the "slow down" light in the event of cat. overheating.

 

Thanks for the correction. Those dang CH cars always confuse me as they are always somewhere not really Euro and not US.
I think also the smog pump may have just been on the 2v cars.

 

I think they were designed just to add confusion and "mystery"

 

The twin cats stopped with 83 models. 84 and on were single cats

 

what about the air injection?
will engine performance degrade if it is disconnected or non-functional?

 

no.

some states do not require older cars to meet emissions anymore. many here do not have the equipment installed at all.

 

As soon as you can get away with it (depending on the state) just yank it off and get rid of it.

 

is that a yes or a no with regard to engine performance degradation?
if big brother is reading this forum,we are voting for the wrong folks!

 

The early cars made do with air injection into the exhaust stream only upon deceleration and NON CAT legal thru 1977..a thermoreactor muffler was often upgraded to a normal ANSA.

After that it gets a little more complicated, so that's why the glass and NON CAT cars are trending upward in value, IMO...

Now that the air injectors and plumbing are aging they can damage your engine, so my systems are stored "off the car" for safekeeping...

 

"how much do you guys charge for not playing...."

groucho marx

 

For the USA:

The 76-77 cars had a heavy thermoreactor muffler (kinda like a primitive cat and muffler in one) with air pumps.

The 78-79 cars were carbed and switched to a pair of cats, plus a muffler, and air pumps.

The 80-82 two valve injected cars had the same setup except with Bosch fuel injection.

Once it gets to the QV in '83, it gets a little more complicated and I'm not that knowledgeable. 83 was an odd year for some models and then everything changed in 84.

Most people at this point have removed the air pumps in states where emissions testing is not required for these cars, and then plugged the exhaust manifolds. It should actually improve the performance of the car and reduce the header temps.


Birdman

 

"You can't afford it"
Chico Marx

The air injection "in theory" should not affect performance so much. However, in the early models with air injection the injection nozzel was this perforated tube that actually hung down in the flow stream. While a hinderence to flow, these also deteriorate with time into a mess hanging down into the exhaust flow. Later cars, probably starting with he qv and certainly by the 3.2, did away with these terrible injectors with an new design injector that did not extend past the wall of the port. there are several old FChat threads on replacements and very nice block offs for these early injectors.

The pumps do rob some hp off the camshaft, but a larger problem is just disconnecting the drive withour removing the pump. I am told that if the air pump is left off the drive yet still hooked up to the system they will seize, and then cause damage if re-hooked up (say for an inspection).

Cats are a somewhat involved story, as cat technology changed as the cars developed. Very briefly, the early cats are quite high resistance, and prone to failure with even more resistance. Later and newer tech cats, such as the 328, were more efficient and had less flow restiction. In the US cars, the single O2 lambda necessitated the single cat system, which does negate some of the exhaust pulsing efficiencies of the flat crank (note that the Euro system stayed separate).