Early versus late 1974 Options

[Lockwodo]

I have owned both 'early and late' '74 2.0Ls.

Do not know of a definitive list of changes, nor the VIN inflection point which seems to be a progressive set of dates depending on the change, not a single date. The factory parts manual may indicate changes to spcific parts associated with a VIN.

Some differences:

-silver center gauges changed to black center gauges
-charcoal canister relocated from fuel tank to engine bay rear wall
-carpeting changed from solid colors to 'salt and pepper' patterns
-a brief period of a few weeks in Spring of 74 when grey headlight relay covers were installed
-fuel expansion chamber and fuel tank cap changed from metal to plastic

Interestingly, the Can Am cars produced in the Spring of 74 include a range of these changes.

Thats all I can think of right now.

As I compared the "early" and "late" vacuum diagrams to my '74 2.0, I noticed that the throttle body on my car only has one vacuum port, and it looks like this port is intended to be connected to the retard vacuum port on the distributor advance can (but the previous owner left it disconnected). The advance vacuum port on the distributor advance can is just sitting there open with nothing to connect to. So my questions are 1) does the distributor vacuum advance can port not need to be connected to a source of vacuum?, 2) should the existing hose from the throttle body vacuum port be connected to the distributor retard can port, or does it matter?, 3) should I find a throttle body with two vacuum ports and connect both to the distributor advance can? As it sits, the car seems to run and accelerate fine without vacuum to the distributor advance or retard. Thanks, Doug

[wonkipop]

@lockwodo ,

the 2.0L guys will have to answer the question you have about retard being hooked up.
........but if 2.0s are anything like 1.8s the retard port is for emissions at idle.
doesn't mean to say they are the same, as 2.0s are D jet.

theoretically it should run better at idle without the retard hooked up.
i think.


-------

@JeffBowlsby .
i downloaded all the CARB documents when i was in the archive getting the 1.8 stuff.

maybe this is of interest to you.
i went back and had a look at them in my files after @lockwodo posted his questions.

Oct 72 CARB documents (covering 1.7s and 2.0s) for 73 model year.
both have vacuum advance and retard activated for distributor/throttle body.








Oct 73 CARB documents (covering 2.0s) for 74 model year.
now only has retard activated for dist/tb.







i'll leave 2.0 experts to work this out.
1.8 stuff gave me enough of a headache.

........it seems to say.
at minimum what is called a late 74 2.0 (hose layout only vac retard) was a california car? just like the 1.8s.

or.
74 2.0 L was a universal car (50 states) and had only retard.

or 74 did change at some stage during model year to conform to CARB.
and was a 50 states car when it did that change as well. ie they just applied CARB requirements across the board.

?????????

[JeffBowlsby]

As I compared the "early" and "late" vacuum diagrams to my '74 2.0, I noticed that the throttle body on my car only has one vacuum port, and it looks like this port is intended to be connected to the retard vacuum port on the distributor advance can (but the previous owner left it disconnected). The advance vacuum port on the distributor advance can is just sitting there open with nothing to connect to. So my questions are 1) does the distributor vacuum advance can port not need to be connected to a source of vacuum?, 2) should the existing hose from the throttle body vacuum port be connected to the distributor retard can port, or does it matter?, 3) should I find a throttle body with two vacuum ports and connect both to the distributor advance can? As it sits, the car seems to run and accelerate fine without vacuum to the distributor advance or retard. Thanks, Doug

73 2.0L two throttle body ports, connect to vacuum can both vacuum can ports to the throttle body per Dave Darlings diagram.

74 2.0L only one throttle body port, connect to vacuum can retard port only per my diagram. The advance port hose is short (~6 in or so) and is not connected, orients under the air plenum. Advance is not functional but thats the way its been documented on numerous cars as from the factory. It was an emissions 'feature'.

[Mark Henry]

It also depends on what was in the parts bin that day, VW was famous for using up what's on hand.

My 914 is a November '73 build, no silver dots.

@Mark Henry

mark, was your car a 1.8 or 2.0 new?

1.8

[Eric_Shea]

As Dan mentioned, pressure regulator changed slightly which means almost all of the rear lines are different (through firewall and left and right).

[wonkipop]

It also depends on what was in the parts bin that day, VW was famous for using up what's on hand.

My 914 is a November '73 build, no silver dots.

@Mark Henry

mark, was your car a 1.8 or 2.0 new?

1.8

front trunk or engine bay can?