Help identifying a vacuum line please.

96stangman · Aug 3, 2013

Hello guys!

First time posting, glad to be here.

I've found a broken vacuum hose, i believe it is. In the photo its on the upper left corner pointed by a red arrow. It leads downstream to some sort of cannister/cylinder that's connected to a hose that goes into the firewall. I cant get another pic of the broken end right. The fitting is snapped after the cannister.

96 Mustang 3.8 5-speed

Does anyone know what is the purpose of this line?

Thanks!

Carlos
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Current Veh: '96 Mustang 3.8 5-speed
White/ Blk-Grey
Only Mod: '96 Cobra Rims 245/45ZR17

Prev. owned: '03 White P71, '93 Silver Civi Caprice LO3, '95 Black 9C1 LT1, '94 DCM 9C1 L99, '91 Blk. Saph. 9C1 LO5, '88 Mustang LX, '93 Mustang LX 5.0, '92 Mustang LX 5.0, '96 Mustang 3.8, '98 Mustang GT, '86 Mustang 3.8.

GT Rob · Aug 3, 2013

Do you need to where it goes I think it's for your A/C

96stangman · Aug 3, 2013

a/c? Ok thanks. So there are two that go to the A/C? Because there is a thin one originating from the vacuum tree that goes into the firewall as well marked "a/c". Thank you then.

ttocs · Aug 3, 2013

does your heater/ac only blow on the windshield?

Walking Tall · Aug 3, 2013

You should be able to pull the piece of broken line out of the fitting and plug the line back in. Happend to me a couple of weeks ago.

CWO · Aug 4, 2013

Pretty sure it goes to the evac canister in the fender well, no?

96stangman · Aug 4, 2013

My ac is working fine at all positions. It's just that I've been experiencing some hesitation off idle and a rough idle and I've changed a few minor things with no improvement (fuel, air and PCM filters). I've been going through the engine checking all hoses and lines and came across this one busted hose.

FYI, I pulled the codes and got back 0174, 0401, 1131 and 1443. From what I've seen these codes indicate lean condition, EGR issues, EVAP canister issues and possible vacuum leaks.

96stangman · Aug 4, 2013

Btw, I've cleaned the MAF and lightly sprayed the TB too.

CWO · Aug 4, 2013

Evac canister in the fender well. You have to pull the splash shield to see it.

g36 monkey · Aug 4, 2013

Yes it's the evap canister. If you are in a state without emissions, you can just plug that thing off entirely.

GT Rob · Aug 4, 2013

Stangman check the vacuum hose on the back side of the lower intake follow the 3 ogre the ones that are coming off the driver side fender well by the brake booster to the back of the lower intakes make sure it's pushed in it happened to me
What motor do you have because mine is a 5.0

g36 monkey · Aug 4, 2013

It's a v6 like he mentioned a little while ago ;p

96stangman · Aug 4, 2013

Guys thank you for all your assistance.

I had a chance to go by the junkyard today and since they usually dont charge for hoses there, I picked up a long section of hose from another 94-98 3.8 and a couple plastic fittings. I worked on the vac hose leading to that little canister-looking thing that goes into the pass side fenderwell to the evac canister that you guys mentioned and also the one at the top of the engine that goes from the drivers side valve cover and connects to the intake tube. The first one had snapped after the little canister and the one to the intake tube was dry rotted and cracked.

I marked the ones I changed in the pics below:

I pieced together the hose leading from the little canister to the fenderwell with two of the fittings and replaced the one to the intake tube.

I reseted the ECU and took it for a drive. The hesitation off the line is GONE. It was hesitating so bad in 1st and 2nd that i needed to rev fairly high to shift smoothly and now thats HISTORY. My idle is still a bit off but this is a start. I'm gonna pull the codes again tomorrow and hopefully I've eliminated a couple of those.

Thanks again guys!

Carlos

CWO · Aug 5, 2013

Good deal. Glad it worked out for you.

96stangman · Aug 5, 2013

CWO said:
Good deal. Glad it worked out for you.

Thanks bro. And someone told me today that little canister-looking thing in the engine bay is called a purge valve. Is that accurate?

CWO · Aug 5, 2013

I believe that to be correct.

MustangChris · Aug 5, 2013

CWO said:
Pretty sure it goes to the evac canister in the fender well, no?

this dude knows whats up.

thats your canister purge valve. Once you hit highway speeds and normal operating temps that valve opens and dumps your gas tank's excess fumes into the intake tract. Once this happens your engine sucks all those fumes in and burns them off. It's good for the environment (the fumes are burned off opposed to just released) and it (supposedly) helps your MPGs.

One side should go into your fender to a big plastic box (which it sounds like you've already discovered) and the other line runs to your intake (which you've already replaced). As long as that valve holds up, you should be good to go!

96stangman · Aug 5, 2013

MustangChris said:
this dude knows whats up.

thats your canister purge valve. Once you hit highway speeds and normal operating temps that valve opens and dumps your gas tank's excess fumes into the intake tract. Once this happens your engine sucks all those fumes in and burns them off. It's good for the environment (the fumes are burned off opposed to just released) and it (supposedly) helps your MPGs.

One side should go into your fender to a big plastic box (which it sounds like you've already discovered) and the other line runs to your intake (which you've already replaced). As long as that valve holds up, you should be good to go!

Thanks man. Yeah, while i was at the junkyard, there was one 3.8 with the fender removed and I saw the canister and where all the lines lead to. I'm sure one day, I'll have to get in there and replace that thing.

Carlos