Hi,

Ok when you say you removed the vacuum line from the FPR thus means you do have a LH vehicle.
You put out that this was a California car so I’m thinking it must have a fuel vapor canister.
My 1984 does one and I think my 1978 GT also has one.
I have owned the ‘78 K jet since 8,000 miles but with having five other 240s to spread my maintenance time across, it’s not a big item to log into my brain anymore.
I’m out of town tonight but I will look tomorrow afternoon to look up under the left or drivers side of the front bumper.
On all my other LH’s it’s in the same place.
It’s Hard to believe your car didn’t get one.

You might want to look for lines and missing things.
How long have you had the car?
Most of the cars have only had one or two other owners and Luckily unmolested at that. Stock has its attributes.

The ‘78 Lambda Sond O2 sensor was the newest thing along with multi injectors. It was a single wire sensor. No heater wire until 1985-6. The sensors doubled in price for that gimmick to fool the establishment some more.
I’m pretty sure the fuel vapor controls were mandated in California for that year.
My 1974 FORD F100 had some EVAP canisters mounted down real low to the right of the transmission. Those promptly rusted into pieces and filled with water.
My 1987 Chevy motor home has them and an air pump.
The air pumps and the EGR valve under the carburetor was a political joke played from both sides. The Solution to pollution IS dilution.
Burn what doesn’t have time to burn, later, in a catalytic converter, didn’t help efficiency either.
The whole emissions “retarding the spark” package was what helped me to never buy another FORD or American vehicles.
I put sights on the EUROPEAN side and hit on Volvos
The Japanese were already turning heads but it took time for “qualities” to sort things out.
We learned the rest of the story in chapters with each passing decade.

The same playbook is winding down on or up on the idea of “battery” powered Electric vehicles.
IMHO this stupidity is going ton hit the global consumers squarely between the eyes, of which, will blindly be pushing consumers into another pollution problem.

Hydrogen fuel cells and capacitor building technologies area looking a lot better to me.
Remember imagination built the “Back to the Future” movie a “Flux capacitor.” 😵‍💫

The UNIVERSE or COSMOS is made of mixes of a foundational carbon structures.
Hydrogen atoms are only one type of energy.
Others area scattered in different forms around us.
I’m sure there are more than nine forms that scientists are using today.
We are only interested enough to exploit the “easiest” ones first like those from hydrocarbons.
Uranium and all its parts, were surprisingly tantalizing to say the least.

The quest for “Energy” will drive mankind's desires to find more of them forever.
Star Trek as entertainment or the space race bug has had that underlying in itself as a reason to even exist.

Maybe not a FPR at this time but it will have a failure, as it is man made and time is very patient. 😬

Phil