misc vacuum line question(s)

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misc vacuum line question(s)

January 28, 2012, 07:08:18 AM

ok, so fiddling around yesterday I was checking things out under the hood. I noticed this vac line that I have been keeping an eye on for a while now. I was pretty sure it was cracked or broken but all the visible areas didn't show it. anyway, I pulled it out and checked it out and well yes of corse it had a giant freakin hole in it. So I replaced it and honestly it really didn't seem to do anything. (other than of course making my idle a smoother since now I'm getting full vacuum)

The line in question is the one that comes from the PCV and T's out to a sensor, then down to the charcoal filter. Now what I mean when I say it didn't seem to do anything is that once hooked up to the charcoal filter, if I pull the other hose off, there is no vacuum at that inlet. But, I know there is not a leak in my filter because once I hook the first hose up to it, the erratic idle does go away. So I guess what I'm saying is, is my charcoal filter clogged or something, or is that the normal method of operation?

And while we're at it, wtf does that sensor do anyway? the one that is inline with the first mentioned hose, that T's off of the PCV line. I play around with it, unplugged the harness, doesn't change anything. Is it faulty or is it similar to the operation of the EGR valve?

misc vacuum line question(s)

Reply #1 – January 28, 2012, 07:06:42 PM

Have you checked the vacuum decal on the fan shroud?

misc vacuum line question(s)

Reply #2 – January 28, 2012, 08:54:38 PM

dont have a fan shroud;)

...and even when I did that sticker was loooooong gone.

misc vacuum line question(s)

Reply #3 – January 28, 2012, 09:22:44 PM

this would be the sensor in question btw....

misc vacuum line question(s)

Reply #4 – January 29, 2012, 12:57:59 AM

From the 88 EVTM:
The thing in the middle is the canister purge solenoid if the wires are RED and GRAY/YELLOW.

misc vacuum line question(s)

Reply #5 – January 29, 2012, 02:11:11 AM

mmm, yes after pulling out my haynes manual that I forgot I had, it confirms that is indeed the canister purge solenoid. I guess it is operating correctly.

Now the thing that I could not verify from my manual is whether or not it is normal to not have vacspooge on the side of the canister that goes to the tank. Anyone know about that?

misc vacuum line question(s)

Reply #6 – January 29, 2012, 01:30:16 PM

Quote from: sarjxxx;379154

mmm, yes after pulling out my haynes manual that I forgot I had, it confirms that is indeed the canister purge solenoid. I guess it is operating correctly.

Now the thing that I could not verify from my manual is whether or not it is normal to not have vacspooge on the side of the canister that goes to the tank. Anyone know about that?

As far as I know its just a vent

misc vacuum line question(s)

Reply #7 – January 29, 2012, 03:33:41 PM

The canister has a vent port under a dust cap. When vacuum is applied to the purge port, air is drawn in through the vent port.
As the gas level in the tank drops while driving, air from the vent port goes to the tank.
Since the canister is open to the atmosphere you won't see any vacuum on the vapor port to the tank.

Sarjxxx vacuum question

Reply #8 – February 16, 2013, 07:12:07 PM

Hey Sarjxxx, i was trying to find the location of a vacuum line on my 88 3.8 cougar when i stumbled on your thread. Maybe you can help me, the pcv valve vacuum line, not the one that you are talking about, but the other one that runs from the pcv valve to the back of the intake, it is a metal line with rubber on both ends where it connects to the pcv valve and the intake. There is a nipple in the metal portion about half way in line that points downward. I for the life of me cannot find what that nipple is suppose to connect to, i plugged it off temporarily but do you know what it is suppose to connect to?

misc vacuum line question(s)

Reply #9 – February 16, 2013, 07:51:59 PM

The purge solenoid is not energized at IDLE. It only energizes at cruse or at a set point in the ECM parameters. If allowed to have straight vacuum at idle the engine would be running very rich. This is because the stored hydrocarbons would be sucked in to the intake stream at idle. As far as i know no canister purge is activated at idle. So repairing it made no difference with idle quality. If on the vacuum side of the solenoid it would. But not on the line going to the canister. Remember solenoids are activated by the ECM sometimes are delayed. Example EGR VALVE CANISTER PURGE!!

:flame::hick:

misc vacuum line question(s)

Reply #10 – February 16, 2013, 10:12:04 PM

Quote from: wjabar06;409494

Hey Sarjxxx, i was trying to find the location of a vacuum line on my 88 3.8 cougar when i stumbled on your thread. Maybe you can help me, the pcv valve vacuum line, not the one that you are talking about, but the other one that runs from the pcv valve to the back of the intake, it is a metal line with rubber on both ends where it connects to the pcv valve and the intake. There is a nipple in the metal portion about half way in line that points downward. I for the life of me cannot find what that nipple is suppose to connect to, i plugged it off temporarily but do you know what it is suppose to connect to?

Actually that is what I was talking about in this thread. Look in the picture in the post above. The picture is sideways for some reason, but you can still see how the PCV line from that T you're talking about connects to the Canister Purge Solenoid and then goes from there to the canister itself, the odd looking black box with two vacuum lines going to it, it's behind the radiator on the passenger side.

Thanks man

Reply #11 – February 17, 2013, 11:45:49 PM

Okay now that i look at it I see what you mean, that makes sense, previous owner has that screwed up, the solenoid that is the focus in your picture, was hooked up to the pcv valve directly on top nipple...so i see what you mean and yes that is the t i was referring to....now what i'm trying to figure out is what gets hooked in to the top nipple of the pcv valve, it doesn't look look like you have anything on it in the picture?

misc vacuum line question(s)

Reply #12 – February 18, 2013, 05:27:45 AM

yep nothing connects directly to the PCV valve itself. That is a replacement from the parts store that uses a generic design probably actually intended for a different vehicle but just happens to work with ours if you leave that second nipple capped. The original valve that Ford put on there didn't have that second one.

misc vacuum line question(s)

Reply #13 – April 28, 2013, 11:56:10 AM

Hi guys. Sorry for reopening this old thread, but I have relevant question - does somebody have complete vacuum diagram for 85/86 turbo coupe? There is an A/C part in the EVTM and a very small schematic on the bottom of the hood.
I was looking for it even in the shop manuals but without any result. Maybe I missed it.

The reason why I'm asking is, that some idiot played with the vacuum lines and for example the EGR valve was connected do the boost gauge. Really dunno why.

misc vacuum line question(s)

Reply #14 – April 28, 2013, 08:10:16 PM

Quote from: Trinom;414064

Hi guys. Sorry for reopening this old thread, but I have relevant question - does somebody have complete vacuum diagram for 85/86 turbo coupe? There is an A/C part in the EVTM and a very small schematic on the bottom of the hood.
I was looking for it even in the shop manuals but without any result. Maybe I missed it.

The reason why I'm asking is, that some idiot played with the vacuum lines and for example the EGR valve was connected do the boost gauge. Really dunno why.

Check Shop Manual Volumn HC.