engine bay hoses 1.8 L Jet, colors, arrangements etc Options

[wonkipop]

this topic arose in the thread concerning hose colors for D Jet cars.

i've started a new topic so it does not mess the other thread.

first thing to say is that the factory manual is more scant on L-Jet information than for D-Jet. There are no hose schematics with the clarity of the D-Jet layouts for the L-Jet. Secondly some of the information on the L-Jet is misleading.

First thing.

car 1974 1.8.

Green vacuum line from Distributor.
Seems to be the same as the D-Jet cars.

There is a green vacuum (retard) line out of the distributor body to the throttle body.
I think i am right saying its the retard side (sometimes gets dyslexic on that).

The green line in this photo is an original vacuum line. Along with the crankcase vent hose these are the only two lines i did not replace on my car. The crankcase line is moulded to an S - shape and we decided to stay with the original. its still sealing ok.
Same with the distributor line. We checked and still pliable and it was sealing so it stayed. We cleaned it up a little. I also left the intake manifold seals on as we did not go that far in - requires disassembly of the intake manifold. They are still in good sealing condition though looking a little aged.

There is a black vacuum (advance) line out of the distributor to the throttle body.

The green line from the distributor was the only colored line still apparent on my car.

[JeffBowlsby]

Thanks Wonk. I have said before that your research on that emissions brochure is commendable and I have always appreciated your support and logical rationalization. Both hose routing methods function, so use whichever you prefer. But to my eye, the brochure solution is questionable in its functional effectiveness.

The hose configuration in the brochure results in a short circuit for fuel vapors, in that they enter the one end of the canister and are immediately 180'd back out the adjacent hose, propelled by positive air pressure from the other end of the charcoal can and the suction air from the engine intake so that the vapors do not travel through much charcoal media - with resultant limited effectiveness at cleansing the air path from fuel vapor - the entire intent of this system.

My diagram conforms to the 'early' configuration in that the positive pressure supply air input hose forces fuel vapors to travel through the entire charcoal media, which are propelled by both the positive airflow from the fan and the suction air from the engine intake. To my eye it works better at minimizing fuel odors and directing them back into the engine where they are combusted. This is also the hose configuration in my 50K mile 1974 2.0L that had original hoses when I acquired it about 20 years ago from the original owner.