94 Explorer Vacuum-Line madness (pics inside)

[KiloWatts]

Greetings!

I've started learning about my Explorer, and through various DIY repairs, the vacuum lines have become mixed up. I'm following the diagram, but have a few questions. Here's the rundown:

Here's the diagram. The items I can't locate are: Brake Booster, A4LD trans, FPRC, and Speed Control.

Here's where everything's plugged in. The EVR and EGR are correct. #1 goes across the top of the intake and down through the back somewhere. #2 and #3 go to two devices on the driver's side which you'll see clearly below. I plugged #4 and #5 because I don't know where they should go. There are 7 vacuum-line holes, but only five are used. According to the diagram there should be six, so at least one device is not receiving vacuum.

What are #1, #2, and #3 connected to? #1 is very stiff, and goes across the intake and down through the back somewhere.

I think I figured this one out correctly. The CANP is a little solenoid going to the CAN, which is called a Charcoal Canister. I don't know its exact function. I'm also unsure whether it's connected the right direction. This is the only way it would fit (short line leading left, and longer leading to the CAN) A bigger question is whether I have the short line connected to the right spot (see below):

This is what I THINK is the Throttle-Body hole in the diagram, leading to the CANP.

And finally, (slightly unrelated), just want to make sure this is correct. That's the DFPE. Front line is connected to the top EGR-tube hole. Back line is conncted to the bottom EGR-tube hole. I don't remember which hole is in or out.

Back to the diagram: In the top left there's a "Main VAC" leading to the PCV valve. Where is that, and from which vac-hole? Everything else on the left I haven't fussed with yet.

Thanks for your time...

 

[Tbars4]

..The PCV and it's hose plug directly into the rear of the intake manifold..It does not lead up to the "octopus" Main Manifold vacuum multi connector thingy..

..Some of your notes you put on your pictures are incorrect..but it looks like most everything is plugged in correctly which let's you follow the diagram to learn more about what it means..:biggthump

 

[KiloWatts]

Thanks... If you have time, which notes are incorrect?

Also, if I only have 5 hoses plugged into the octopus, which one is missing?

 

[KiloWatts]

Okay, after researching the Fuel Pressure Regulator, I found it and it was the missing connection! I've plugged it into the 'octopus' now, so everything should be correct now.

So now I've just narrowed it down to identifying the Brake Booster, A4LD, and Speed control.

 

[Rick]

The black round canister behind your master cylinder is the power brake booster. The large vacuum line is correctly plugged in.

I don't have an auto trans or speed control so I can't help with that.

 

[arco777]

Okay, after researching the Fuel Pressure Regulator, I found it and it was the missing connection! I've plugged it into the 'octopus' now, so everything should be correct now.

So now I've just narrowed it down to identifying the Brake Booster, A4LD, and Speed control.

The A4LD (trans) vac line runs down to the passenger side of the trans and hooks to the vacuum modulator. If you're experiencing 3000RPM shifts from 1-2, then there may be an issue with this line - otherwise it should be fine.

Brake booster is the round cylinder on the firewall and from your pics it's hooked up correctly.

Speed control is also hooked up fine, it's the round cylinder-lookin thing on the drivers side fender.

Do you have any actual driveability problems or a CEL? Otherwise everything should be hooked up fine - you'd notice if there was a vac leak.

 

[L.A.X]

I know this is an old thread but I need help

 

[L.A.X]

What is the long plastic cylinder looking thing on top of the heater box? Where does the vacuum line to that go?

 

[arco777]

It's a vacuum reservoir.

 

[Tbars4]

From the reservoir, that plastic line will run over to the right fender into a wire cluster just to the bottom left of the heater fan..(between the fan and the fender)..

..This is how that vacuum line enters into the cab and runs behind your glove box over toward your heater controls..

 

[MFrankln]

Amazing - THANK YOU!

I have a '93 Explorer XLT that has had a vacuum leak since I got the vehicle as a birthday gift in 2011. Could never find it.

In order to keep it running, I had to unplug the Mass Air Flow sensor and keep both feet busy to maintain idle. Even then, it ran rough.

But from Picture 4 below, I was able to locate the vacuum nipple that was hidden behind a half dozen other lines. Once properly plugged (as noted in image as it should be), I reconnected my MAF sensor and... she's running normal again!

I about jumped out of my boots!

I wish I could invite the author/owner of this thread and image over for a beer and some BBQ!

My baby is back to normal...

Thanks so much,

Mike

 

[damnford]

this helps me a lot as well most of my lines are disconnected.

 

[Roadrunner777]

Just a few related notes...
There is a line going from the cruise control servo to points apparently unknown. It actually goes through the firewall and under the driver's side dashboard, to the brake pedal bracket. It's a safety feature that dumps the servo vacuum if you hit the brakes. If your cruise control is intermittent, the dump valve on the brake pedal is a common issue.

Also, I had to run for a few months with a bad tranny modulator due to weather, and some trans fluid got up in the modulator vacuum line, soaking the rubber end where it connects to the octopus. I never could get that really tight again, and sometimes in very cold weather, I would get a misfire blowing this hose off the octopus. When that happens, it makes an incredible sucking sound and shifts poorly. I'm not a big fan of how they used rigid plastic tubing and rubber ends. It's very difficult to repair reliably.

Ok, there's my 2 cents.

 

[Pablof122]

Greetings!

I've started learning about my Explorer, and through various DIY repairs, the vacuum lines have become mixed up. I'm following the diagram, but have a few questions. Here's the rundown:

View attachment 324979

Here's the diagram. The items I can't locate are: Brake Booster, A4LD trans, FPRC, and Speed Control.



View attachment 324980

Here's where everything's plugged in. The EVR and EGR are correct. #1 goes across the top of the intake and down through the back somewhere. #2 and #3 go to two devices on the driver's side which you'll see clearly below. I plugged #4 and #5 because I don't know where they should go. There are 7 vacuum-line holes, but only five are used. According to the diagram there should be six, so at least one device is not receiving vacuum.



View attachment 324981

What are #1, #2, and #3 connected to? #1 is very stiff, and goes across the intake and down through the back somewhere.



View attachment 324982

I think I figured this one out correctly. The CANP is a little solenoid going to the CAN, which is called a Charcoal Canister. I don't know its exact function. I'm also unsure whether it's connected the right direction. This is the only way it would fit (short line leading left, and longer leading to the CAN) A bigger question is whether I have the short line connected to the right spot (see below):



View attachment 324983

This is what I THINK is the Throttle-Body hole in the diagram, leading to the CANP.



View attachment 324984

And finally, (slightly unrelated), just want to make sure this is correct. That's the DFPE. Front line is connected to the top EGR-tube hole. Back line is conncted to the bottom EGR-tube hole. I don't remember which hole is in or out.



View attachment 324985

Back to the diagram: In the top left there's a "Main VAC" leading to the PCV valve. Where is that, and from which vac-hole? Everything else on the left I haven't fussed with yet.

Thanks for your time...

Great job! Thank you. The photos and diagrams have clarified many doubts. Although I still can't find out why it stays at 1500 rpm in idle mode.

 

[ChildIdenticant]

Although I still can't find out why it stays at 1500 rpm in idle mode.

Pablof122 If having trouble, consider posting a new thread in the first gen forum with explanation of your issue.

 

[RangerX]

Great job! Thank you. The photos and diagrams have clarified many doubts. Although I still can't find out why it stays at 1500 rpm in idle mode.

Remove your plastic air intake tube and turn it over. Check the accordion pleats for cracks and broken pieces. Remove it carefully so you don’t break it further, 29 year old plastic can be fragile!
I patched the damage on both my trucks using 1” silicone tape.