Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

Thing on top of the valve cover (picture)

Thread Tools
 
Search this Thread
 
Old Aug 13, 2009 | 02:33 PM
  #1  
Junkers88's Avatar
Thread Starter
Registered User
 
Joined: Mar 2008
Posts: 4,371
Likes: 6
From: Texas
Thing on top of the valve cover (picture)

So I was thinking that it was strange that my rear main just suddenly started leaking and decided to replace the PCV valve and grommet just in case it was plugged. I can't tell if the leak has stopped yet but I don't see any new drips.

Anyway.... while I was messing with the PCV thing with the engine running I noticed two things.

1) There was a freaky sucking noise that came and went.
2) When the noise was present the idle would drop and get rough.

I tracked it down to this tihing. (in yellow)


Now if I pull this hose off (again in yellow) and plug it with my finger then the idle gets smoother I still have some slight miss but it's less apparent when I plug this hose.


So what is that thing and what does it control?

I tried to search for it but I don't know how to look for pictures.
Reply
Old Aug 13, 2009 | 02:54 PM
  #2  
iamsuperbleeder's Avatar
Contributing Member
 
Joined: Feb 2008
Posts: 12,248
Likes: 33
From: Lake City, Fl
that would be the AC idle up solenoid, and the two hoses run over to the idle up valve

why it's screwing up the idle though, I dunno

I CAN tell you that when the valve is not in use (ie the AC is not turned on and running), it is essentially a controlled vacuum leak, and the plastic black cylinder looking thing on the end has a small filter element in it



Last edited by iamsuperbleeder; Aug 13, 2009 at 02:59 PM.
Reply
Old Aug 13, 2009 | 03:12 PM
  #3  
abecedarian's Avatar
Registered User
 
Joined: Mar 2008
Posts: 12,723
Likes: 6
From: Temecula Valley, CA
The cap / filter on the end of it allows it to equalize pressure internally so that when the valve is turned off, it doesn't get stuck in the 'on' position by vacuum in the tubing.

The "controlled vacuum leak" is the valve on the side of the manifold which sources air from in front of the throttle plate in order to provide a metered source of air (air goes through the AFM so the mixture isn't affected) when the idle speed is raised by that VSV or by the power-steering unit.

If you're getting air being introduced to the engine through the cap on the VSV, there's a good chance that the unit on the manifold is malfunctioning, allowing vacuum up the hose it shouldn't be or the VSV itself is getting stuck 'half-on/half-off'.

Last edited by abecedarian; Aug 13, 2009 at 03:15 PM.
Reply
Old Aug 13, 2009 | 04:04 PM
  #4  
93YotaGuy's Avatar
Registered User
 
Joined: Jul 2009
Posts: 319
Likes: 0
From: Denver, Colorado
Try switching the hoses around for the ac idle up valve and see if it works. I had mine flipped around and it was making that noise. Switch the hoses and you should be fine
Reply
Old Aug 13, 2009 | 05:34 PM
  #5  
Junkers88's Avatar
Thread Starter
Registered User
 
Joined: Mar 2008
Posts: 4,371
Likes: 6
From: Texas
Originally Posted by 93YotaGuy
Try switching the hoses around for the ac idle up valve and see if it works. I had mine flipped around and it was making that noise. Switch the hoses and you should be fine
I tried that and the idle was dead level but I wasn't sure if it was something I could run like that, you know..... change something and ruin something else. I have a 3 hour trip planned for tomorrow to do some fishing and didn't want to kill anything. On a side note I did spend about 2 weeks re-running the jacked up vac hoses from the guy I bought it from so it may have been crossed all this time.

I don't really understand the vacuum routing on this thing.......... so many hoses.

So if I switch the hoses and it runs better should I do it? I did a hose re-run a few weeks back and actually lost the codes for the O2 sensor and the EGR (no more CEL) but the CEL for the EGR came back with the odd miss at idle.
Reply
Old Aug 13, 2009 | 05:39 PM
  #6  
myyota's Avatar
Registered User
 
Joined: Oct 2006
Posts: 4,166
Likes: 11
From: GrangeVille, Idaho
Just switch the hoses, it won`t hurt anything.
Reply
Old Aug 13, 2009 | 05:44 PM
  #7  
BigBluePile's Avatar
Contributing Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Dec 2006
Posts: 15,191
Likes: 190
From: Sedro-Woolley, WA
You could shoot it...





Reply
Old Aug 13, 2009 | 06:01 PM
  #8  
Junkers88's Avatar
Thread Starter
Registered User
 
Joined: Mar 2008
Posts: 4,371
Likes: 6
From: Texas
Originally Posted by BigBluePile
You could shoot it...





Yeah but then your competition would be gone......


How would David feel if someone shot Goliath? Yup....... that's how you'd feel............................

Lost, Confused, Upset and lost in history as the guy that might have out wheeled my runner.


Oh did I mention I'm going fishing in the morning? *hugs*
Reply
Old Aug 13, 2009 | 06:04 PM
  #9  
iamsuperbleeder's Avatar
Contributing Member
 
Joined: Feb 2008
Posts: 12,248
Likes: 33
From: Lake City, Fl
Originally Posted by BigBluePile
You could shoot it...





that's always an option

like the old saying, "If it doesn't fit, force it. If it breaks, then it needed to be replaced anyway"

Reply
Old Aug 13, 2009 | 06:05 PM
  #10  
BigBluePile's Avatar
Contributing Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Dec 2006
Posts: 15,191
Likes: 190
From: Sedro-Woolley, WA
ROTFLMAO!!!!!


Fishing??! Man, I gotta go to work. Plus, I took the bumper of my truck so I'm down for a while anyways...
Reply
Old Aug 13, 2009 | 06:15 PM
  #11  
93YotaGuy's Avatar
Registered User
 
Joined: Jul 2009
Posts: 319
Likes: 0
From: Denver, Colorado
I just looked on mine and you do have it the wrong way.

Also I think when it is plugged in wrong the AC Idle up valve doesn't work.

Easy fix to re-route the hoses
Reply
Old Aug 13, 2009 | 06:25 PM
  #12  
Junkers88's Avatar
Thread Starter
Registered User
 
Joined: Mar 2008
Posts: 4,371
Likes: 6
From: Texas
Originally Posted by iamsuperbleeder
that's always an option

like the old saying, "If it doesn't fit, force it. If it breaks, then it needed to be replaced anyway"

Like that head gasket?



Just kidding man! Just kidding!!!
Reply
Old Aug 13, 2009 | 06:26 PM
  #13  
93YotaGuy's Avatar
Registered User
 
Joined: Jul 2009
Posts: 319
Likes: 0
From: Denver, Colorado
Originally Posted by Junkers88
Like that head gasket?



Just kidding man! Just kidding!!!

Haha that was COLD!
Reply
Old Aug 13, 2009 | 06:33 PM
  #14  
BigBluePile's Avatar
Contributing Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Dec 2006
Posts: 15,191
Likes: 190
From: Sedro-Woolley, WA
ouch...

...funny though!
Reply
Old Aug 13, 2009 | 06:34 PM
  #15  
Junkers88's Avatar
Thread Starter
Registered User
 
Joined: Mar 2008
Posts: 4,371
Likes: 6
From: Texas
Originally Posted by BigBluePile
ROTFLMAO!!!!!


Fishing??! Man, I gotta go to work. Plus, I took the bumper of my truck so I'm down for a while anyways...
Oh so a bumper is going to stop you from wheeling?

FYI work is something you do to live, don't live for work...... you'll die old and pissed off with a pile of money for the kids (or in my case for the EX). Dude take your days and run with them, fish, hunt, wheel, live and love life.

God gave you the gift of life. Take that gift and run with it. You should not show up at the gates of Heaven in a clean suit, with no scars and smiling. You should slide into those gates on your ass with a half finished beer in one hand and a fishing rod in the other and exclaim "Damn that was one hell of a ride!!!!!" Live like you have no future.


Junkers88 3:17 states "No one else can step into your shoes and smile as much as you have".
Reply
Old Aug 13, 2009 | 06:46 PM
  #16  
abecedarian's Avatar
Registered User
 
Joined: Mar 2008
Posts: 12,723
Likes: 6
From: Temecula Valley, CA
Originally Posted by Junkers88
Oh so a bumper is going to stop you from wheeling?
...
Well, yeah, it could.
Reply
Old Aug 13, 2009 | 06:57 PM
  #17  
BigBluePile's Avatar
Contributing Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Dec 2006
Posts: 15,191
Likes: 190
From: Sedro-Woolley, WA
Originally Posted by Junkers88
Oh so a bumper is going to stop you from wheeling?

FYI work is something you do to live, don't live for work...... you'll die old and pissed off with a pile of money for the kids (or in my case for the EX). Dude take your days and run with them, fish, hunt, wheel, live and love life.

God gave you the gift of life. Take that gift and run with it. You should not show up at the gates of Heaven in a clean suit, with no scars and smiling. You should slide into those gates on your ass with a half finished beer in one hand and a fishing rod in the other and exclaim "Damn that was one hell of a ride!!!!!" Live like you have no future.


Junkers88 3:17 states "No one else can step into your shoes and smile as much as you have".
Shoooot, no doubt!! You get one shot at this so GIT-R-DUN!!!!!

Actually, the kids and I('cause the wife has been onboard the USS Ronald Reagan since May and "might" be back November...) are takin the weekend off because we've been out and about almost every weekend doing something . Next weekend I'm probably going wheelin though! Besides, if 380,000 of us decide not to go to work tomorrow then there's no Air Support for the guys on the ground somewhere.


Go Navy

BTW, thanks for the pay check!!!!
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bigjstang
86-95 Trucks & 4Runners
21
Jun 2, 2025 03:56 PM
RedRunner_87
95.5-2004 Tacomas & 96-2002 4Runners (Build-Up Section)
84
Jun 1, 2021 01:51 PM
msane99
Pre 84 Trucks
6
Jul 11, 2015 08:08 PM
icentropy
86-95 Trucks & 4Runners
4
Jul 9, 2015 02:12 PM
Gamble_STi
86-95 Trucks & 4Runners
2
Jul 7, 2015 07:54 PM




All times are GMT -8. The time now is 07:45 AM.