Anyone have a picture of a smog pump installed on a 1.8? Options

[DaveB]

Need help again. I found out my car was originally from California. Any indication of smog equipment is gone. So how is the smog pump mounted to front of the engine? I've seen the parts and would like to see an engine with this installed.

Thanks,

DaveB

[wonkipop]

@DaveB

thanks for the photo. appreciated.


link to a thread in the originality section of this website.

http://www.914world.com/bbs2/index.php?showtopic=357407

the discussion is 1.8s in 1974.
at the bottom of the first page is the hose diagram for the 75 1.8 cal spec.
that helps you.

if you read the thread as well you will get the basics of the 1.8s from 74 which helps you then with how it went in 75.

the truth is in some ways more has been forgotten about the 1.8s than any other variant of the cars. jeff bowlsby has prompted a few of us who own them to do some work to get a bit more forensic about them.

a few of us who own 74s got to the bottom of those in much finer detail last year.

i was thinking of putting out a call to 75 owners when i had a little spare time this year to do the same thing.

the simplest way to put it is they are all variations on a theme.

once you get the basics of the theme it gets a lot easier to see how each version worked. they all have a double vacuum distributor. but they do not necessarily make use of both functions of the distributor.

they all have a similar but slightly different variation on the throttle body.

does your car run an L jet system or has it been converted to carbs.

if its still got an L jet set up on it post up some photos of whats there.
distributor, throttle body and a general view or two of the top.
take some shots underneath of the heat exchangers.
we can tell you exactly what you have on your hands then.

the main things that differ from 74 to 75 will be the following.

the throttle body and how it is connected to other things.

the distributor and how its vacuum connections are made.

the decel valve.

whether its got an EGR or not.

the charcoal cannister, how it is connected up and mounting location.

the exhaust system.


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the way all of these cars worked in emissions terms, being early "smog" cars was by using retarded ignition and lean mixtures.
the retarded ignition and lean mixture cut down NOx emissions from the engines.
as a side effect though CO emissions increased.
when these cars finally got cats these early strategies got the last component that did the job. the increased CO was dealt with by the cat which converted the CO to CO2.
the cat also converted hydrocarbons that were unburnt to CO2 and H2O. the early cats did not react with NOx. NOx strategy was retarded timing settings.

there was no need to use a smog pump with the 1.8s. they ran clean enough to pass with the above strategies.

the 49 state EC-B of 74 ran clean at idle with retarded timing and lean mixture.
"clean" meaning it produced lower amounts of NOx. (main ingredient of smog).
it was clean sitting in an urban traffic jam.
it ran hotter at idle.

the cal state EC-A of 74 ran clean at idle and clean at cruise and part load.
(retarded timing and lean mixture in both those conditions).
ie it was "clean" sitting in a traffic jam or cruising on the freeway.
but it ran hotter in both those conditions.

the 49 state EC-a of 75 duplicated the 74 EC-A (cal). the set up was the same.
however it had an updated decel valve and it used the 75 exhaust system, heat exchangers and mufflers minus the cat and EGR.
the ECU and the AFM were also slightly updated and changed.

the cal EC-b of 75 had the full set up that all 50 states were intended to achieve in 76.
(the 1.8s never made it to 1976).
it ran "clean at idle via retarded timing like all the others.
it ran clean at cruise using the EGR. a lot cleaner than all the other versions.
the EGR may have marginally increased fuel economy and also may have allowed the engine to run slightly cooler at cruise. the EGR did not work at all time. it was activated by vacuum from the throttle body.

when you get your head fully around what they were doing with the throttle body it gets a lot easier to see how the various additional systems work.

most folks just tore this stuff as soon as it wore out.
the exhaust system was more expensive. so it got replaced with the 74 system as soon as the mufflers or the heat exchangers rusted out.
without the original exhaust system the EGR could not work so it would get torn off.

and if you want to put it back on you have to go find those items.
which will be rare and getting rarer. particularly the exhaust system.

setting up to 74 spec is easier to do. the parts are still relatively obtainable.

EDIT

i forgot to mention that 75 Cal 1.8 also ran a different distributor.
without speed limited rotor.
it had a fuel cut off switch (a kind of relay like component) positioned under the battery off the side of battery support where other EFI L jet relays were. this switch replaced the speed limited rotors on the distributor that was fitted to all other 1.8 variants.

i found out way too much late last year doing our "research".
still processing a lot of it. so apologies for info download.

there is more detail, but its best to just step your way into it and ask questions as you go. i don't know everything and i don't own a 75.

but guys on this website between them will have all the detail down to the nitty gritty.