throttle edge tapping vacuum hose

[Jay89]

So my hose that connects to the "throttle edge tapping" was not connected when I purchased the car. It was just put into an incorrect spot.
I just need a little help finding where it goes and what the best way to do that is.
I had a little look today but couldn't really see where it would go.
Do I have to remove anything to get to the spot?
If anyone can help me out, that would be great.
Also if this hose isn't connected, what would it cause?
23178
even with the diagram I couldn't find the spot :facepalm:

[sdg3205]

It's UNDER the mixture unit. It actually attaches to a nipple on the portion of the unit that houses the butterfly valves. It might be tough to locate because the water pump sits in the way, but it's not tough to get at.

Worst case scenario, just remove the W-pipe to access the nipple, then replace the 2 paper gaskets with a little sensor safe silicone gasket maker and reinstall the w pipe. Paper replacement gaskets are ideal tough.

Does that all make sense?

[Jay89]

Thanks, I have spotted the nipple!
Could only get one finger to touch it though.
So getting the hose on it will be very hard, may have to remove the w-pipe like you said.
Also the hose looks like it would be too small to fit over the nipple anyway?.
My hose has split so I will need to get a new one.
23189

[DMC5180]

The hose nipple is smooth (no barb). The hose will expand over it. Are you replacing the hose or just cutting the end on the 32 year old original? Fresh hose will go on easily old stiff hose may not.

[Jay89]

Will probably aim for a new one

[Jay89]

With this vacuum being unplugged. Should I be able to feel air coming out of the end of it?
Because I can't feel anything coming from it.

[DMC5180]

Need a little more info of what and where things are disconnected.

Engine must be running for a vacuum (suction) to be present. With the hose disconnected it would be a source of a significant induction leak and the engine will have a lean idle condition.

[OverlandMan]

FWIW I just replaced this exact vacuum line. It's 5/32 diameter common stuff you can buy @ your local auto parts store. My old one was rather perished.

[dustybarn]

The edge tapping port is connected only to the charcoal canister control vacuum port. It is drilled so that little or no vacuum appears at that port at idle, causing the purge control diaphragm to remain closed and restricting the canister purge rate. When you depress the throttle, the edge of the throttle plate passes the port drilling, causing vacuum to appear only off-idle, opening the canister purge valve and allowing a higher canister purge rate. If that hose is disconnected, it would cause a vacuum leak that appears only off-idle. It would also prevent the carbon canister from purging correctly.

In many cars (but not the DeLorean) this port is also used to provide vacuum to the distributor vacuum advance.

[DMC5180]

The edge tapping port is connected only to the charcoal canister control vacuum port. It is drilled so that little or no vacuum appears at that port at idle, causing the purge control diaphragm to remain closed and restricting the canister purge rate. When you depress the throttle, the edge of the throttle plate passes the port drilling, causing vacuum to appear only off-idle, opening the canister purge valve and allowing a higher canister purge rate. If that hose is disconnected, it would cause a vacuum leak that appears only off-idle. It would also prevent the carbon canister from purging correctly.

In many cars (but not the DeLorean) this port is also used to provide vacuum to the distributor vacuum advance.

Nice explanation and I stand corrected on the idle condition :thumbup:

I was not aware the port was so close to the throttle plate.

[JohnZ]

I'm sorry, Have you got any pictures about this throttle edge tap? It seems that in my car that hose goes nowhere and I want to put it on... but I wanted to be sure about where it has to go!

:)

[Ron]

I don't have a pic of the flip side but:
27677

It is also #19 HERE (http://store.delorean.com/c-334-1-4-1-air-induction-system.aspx).

[JohnZ]

THanks man! I spotted something similar but I wasn't sure about it!