It appears that I am missing a hose for my D-jet fuel injection, from the engine/fan shroud to presumably the air box. I have looked up diagrams, but still confused as to if or where a hose will go to from here. One diagram that many use, does even show the black circle with the hose opening on top of the engine/fan shroud that I do have a hose connected to next to the open one. I also wonder if the hose going from the black circle opening on top of the engine/fan shroud (yellow arrow) to the air box should be on the open nipple (or whatever you call it) next to it that is missing a hose (white arrow).

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I don't believe you're missing a hose--- it's simply in the wrong place. Move the hose from that black thing on the cooling housing, which you will find is a threaded cap to allow access to your timing marks ( if i remember correctly) over to that little stub of tubing sticking up in the first pic. That is I believe a flash supressor and a " t" for your crankcase vents coming out of each head. I'm sure some here will chime in if I'm wrong. I just replumbed my engine after having it out for 5 yrs. Had to look up all that stuff in various manuals. Pretty sure placement is your only problem here.

Hose goes from air box to missing fitting.

A to A

The black plastic timing cover ( right A) should not have a fitting on it.

Great, thank you guys! I always thought the black opening was always just open if memory served me correctly. Thanks, I appreciate it!

Ya the plastic cap should not have a hole or be open. It decreases your cooling capacity by allowing air to escape that should be routed over the heads.

Do you have any fittings on the fan shroud, or on the side of the right-side engine tin? If not, the fitting on the timing hole plug might be substituting for that.

In that case, the timing hole plug fitting would connect to the charcoal canister, either by going through the driver's side long up to the front of the car, or by going directly to the canister in the engine bay. (74 was a transition year; some of them had the early-style front-mounted canister and some had the late-style engine-bay-mounted canister.)

--DD

So I need to plug the hole on the black plastic cap with something? What did the factory use? What do most people use to close it up with?

Okay I got a bit lost there. I'm not too much of a wrench and know my way around the engine bay a little bit, and I've heard of the charcoal canister but have no idea what it is, where it is or what it does.

Mine is a '74 (14 February 1974 to be exact).

On my 72 it's up front , opposite the fuel fill, on top the gas tank in front of the driver. Has single hose coming out drivers side, two different sizes coming out the passenger side. The two bigger hoses are equal size and drop into the car in the corner of the trunk, right by the front of the door. They come up in the front left corner of the engine compartment and one runs to the air cleaner and the other runs to a fitting very similar to the one you were originally asking about, except it is on the front right corner of the engine, on the same aluminum casting as the other fittings in question. It pokes out the right side instead of the top. Remember this is a 72-- Yours may be a bit different. If you don't have the fitting on the right side perhaps you should have a hose on that plastic cap. It would accomplish the same thing. Someone may have removed or disconnected the plumbing to your charcoal canister. Shouldn't be a big issue unless you have to be smog compliant, in which case you would fail the visual -- unless the tech had no idea what he was looking at. If you have that fitting on the right and there is a hose connected to it , I would plug the black plastic cap. On my 72 the canister looks sort of like the cans you see containing acetone or toulene in the hardware store, except bigger. A sort of rectangular box with rounded edges. Hope that helps. My cap has no hole. It just threads into the fan shroud.

Anybodyhave a picture of what the cap looks like that's supposed to go over this, where I can find one or a part number?

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Some 914s have a 12mm fitting on the left side of the fan shroud, some on the top cylinder tin on the same side, and I think some have it on the right end of the shroud. There are also some cars that have the fitting on the plug used to cover the timing inspection hole. Each car has one of the above, and no car came with 2 or more of the fittings. Changing engines, or parts of engines, can result in multiple fittings, or even no fittings. There is no cap for that fitting on the inspection hole. You would need to find a cap without the fitting. DO NOT eliminate the evap system!

The Cap'n

This is what your timing hole cover cap should look like:

AH! Okay, I recognize it now. Thanks, era and Cap'n. I remember it on one of my other 914s.

Anybody have an extra one of these?

you can have this one for $4. my paypal is dangrouche@juno.com
ships from San Francisco

got the payment; mailing it tomorrow!

Sold! Thanks! Sending payment now.

PS - San Francisco is one of my favorite cities!

Sorry for the hijack but I feel compelled to ask, what can happen if the evap system is eliminated? Could this account for a weak idle when the engine is hot or cause an engine to run rich all the time?

We have seen cars with 2 of the fittings. One was unused, and may have been plugged. It appeared that the two fittings were original to the car, but they may very well have been one of the "just use the parts that are in the bin" cars on the assembly line.

The evap system should not affect how the car runs in any way. It will, however, cut down on passive fuel evaporative emissions, and also on fuel smells in the cabin.

--DD

What is the evap system? what is it used for? Does having it or not having it affect the cooling of the engine or the performance of the car?

The evap system pulls fuel fumes through a charcoal canister and into the air cleaner (and then through the engine). Keeps the HCs from polluting the atmosphere, and has ZERO effect on the engine power (it's a passive emissions system). If it's not there, it's almost certain that the occupants of the cabin of a 914 will smell gasoline fumes, often pretty intensely. Not pleasant, and pretty unhealthy, too.

The Cap'n

Yes I've noticed that. Maybe I should get one. Know where I can find one? Thanks for the info, Cap'n!

First you should determine if in fact you do NOT have one. I suspect the components of the system may be there-- just not hooked up. The diagram posted by Pilotheyer is a very accurate representation of the system in my 72. Post a pic of your front trunk with the gas tank.

Tuma has a 1974 LE. His carbon canister should be in the engine bay, mounted to the rear engine bay wall.

Key words-- "should be".. This is a 40 yr old car. I take back my suspicion that the parts are there. Removing them from the engine compartment would be a lot easier than removing them from the trunk. Well , maybe easier isn't the right word. Sleasier? (ya I know that isn't the proper spelling. It is the attitude.) Hopefully you get my drift.

73 and earlier cars had the canister up front. 74 was a transition year, it could be up front, it could be on the back wall of the engine compartment or it could be on the battery hold down bolt. All three were correct for 74.

Yup, I've seen each of the three in 74 cars. At least two of the three (on top of the gas tank; back wall of the engine compartment) in cars built the same month, 10/73.

--DD

My LE is one of the earliest (possibly the first day of production), so it may have not made the '74 transition yet. Anybody have pictures of where this may be in the engine bay (or wherever it is supposed to be) so I can recognize it and know where to look for it? Never seen one.

pictures here. lots of pix, some are 914, others aren't. Up to you to figure it out.

https://www.google.com/search?q=porsche+914...994%3B300%3B225

The Cap'n

Nope. Don't have one. :/
I'll look around to see if I can find one.