Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: cougarXLS on May 23, 2009, 12:55:51 PM

Title: Vacuum Sucks.... but where?
Post by: cougarXLS on May 23, 2009, 12:55:51 PM
Hello All,

      This is bugging the ola out of me.  There is a vacuum spout off the upper intake on the lower side.  There doesn't seem to be a hose near by.  Where does it go?

      While the motor is running, if I place my finger over the spout, the motor will slow down.  It's like the motor runs fast while this spout is open.

        I've included two pictures one of the spout, and the other to show you the general surrounding area.

Cheers.
Title: Vacuum Sucks.... but where?
Post by: jcassity on May 23, 2009, 01:28:19 PM
no direct answer but feel behind the motor for a loose line.

also follow the vac tree hoses ( on fire wall near wiper motor) and trace those out to the local area

pretty big hose missing there, shouldnt be hard to find.

It probably blew off so you probably have vac issues or carbon buildup somewere likely the egr system.
Title: Vacuum Sucks.... but where?
Post by: Haystack on May 23, 2009, 01:43:43 PM
pcv valve if I had to guess.
Title: Vacuum Sucks.... but where?
Post by: cougarXLS on May 23, 2009, 02:06:33 PM
It's not the PCV, it's hooked up.

This car just had her heads redone, and the shmuck that took it apart, failed to put it back together.  So now I'm stuck cleaning up his mess.

I've been tracing the vacuum lines and everything (except that spout) is connected.  According to the VECI and the books.  But you think I can find this one?
See, it's also possible that a hose is actually missing, and I have been turning the garage inside out.

I just need to know where or where does it go?

Anybody got any more thoughts?
Title: Vacuum Sucks.... but where?
Post by: Dougy_Fresh on May 23, 2009, 02:12:52 PM
looks like a good sized hose, i would say either brake booster or PCV. but u said the pcv is hooked up.....i'm not familiar with the 3.8's, but on my 88 5.0, there is a breather off the oil filler tube that is about that size....
Title: Vacuum Sucks.... but where?
Post by: Kitz Kat on May 24, 2009, 08:38:15 AM
I'll look at my buddy's 88 today and see where it might go.
Title: Vacuum Sucks.... but where?
Post by: cougarXLS on May 24, 2009, 09:40:22 AM
Quote from: Kitz Kat;274046
I'll look at my buddy's 88 today and see where it might go.

I'd appreciate any thoughts. :)
Title: Vacuum Sucks.... but where?
Post by: softtouch on May 24, 2009, 02:01:32 PM
The 88 3.8 is a different animal than all the earlier 3.8's.
Documentation on them is scarce, at least on this board.

Try pulling codes to see if you have any EGR codes.
I believe you have a "pressure feedback electronic EGR system".
The missing hose may have something to do with that.
Title: Vacuum Sucks.... but where?
Post by: softtouch on May 24, 2009, 02:28:08 PM
Can you find a sensor like this that has a hose on it? Or needs a hose on it?
Title: Vacuum Sucks.... but where?
Post by: the_intimidator03 on May 25, 2009, 06:56:39 AM
softtouch... the car in question is also an 88 3.8 SEFI so the 88 to check on is perfect
Title: Vacuum Sucks.... but where?
Post by: Kitz Kat on May 25, 2009, 07:52:39 AM
I looked if it's the connection on the right rear corner looking at it from the front, it goes to a small round vac chamber or sensor not sure what it does. The bracket for it is bolted to the lower intake and the back of the head.the other hose closer to the middle coming off the intake goes to the pvc on the right vc.
I just looked at the pic again I can see the the part I meant.
Title: Vacuum Sucks.... but where?
Post by: jcassity on May 26, 2009, 12:22:07 AM
Quote from: the_intimidator03;274201
softtouch... the car in question is also an 88 3.8 SEFI so the 88 to check on is perfect


there was never a sefi 3.8 made for these cars.  the fuel injected 88 model is the same as cfi.

thats why the intake says "fuel injected" and not SEFI

three injectors fire at once while the other three fire at once, unlike sequential
Title: Vacuum Sucks.... but where?
Post by: CatCarMan2012 on May 26, 2009, 12:10:03 PM
Screw it.  Just cap it (piece of hose + bolt).  If its a problem, you will find out when you try to drive it.
Title: Vacuum Sucks.... but where?
Post by: thunderjet302 on May 26, 2009, 12:10:26 PM
Quote from: jcassity;274366
there was never a sefi 3.8 made for these cars.  the fuel injected 88 model is the same as cfi.

thats why the intake says "fuel injected" and not SEFI

three injectors fire at once while the other three fire at once, unlike sequential



Yeah but the 89 and up 3.8s use the same intake but they are SEFI ;)

You're right though the 88 3.8 is a batch fire EFI system. It's the odd ball of the T-bird/Cougar world.
Title: Vacuum Sucks.... but where?
Post by: cougarXLS on June 01, 2009, 11:34:21 AM
It's definitly not EGR related.  EGR is hooked up according to VECI, and no codes are being thrown.

The only thing I can tell you about the codes, is she throws the 51 (ECT sensor out of range indicated / circuit open) in the key on engine off.  In my expierence, this isn't a ghost code thrown because the block isn't at normal operating temperature (it's usually 21 - Cooling temperature sensor out of specified range or ECT out of range).
This is probably because I have discovered a plug that doesn't seem to go any where.
(http://www.cougarxls.com/pf/rougewire.jpg)

The key on engine running test indicates the computer is running in failure mode.

Quote from: danzajax
Screw it.  Just cap it (piece of hose + bolt).  If its a problem, you will find out when you try to drive it.
.
When we do that the motor runs like , if we don't do that, the motor still runs like  :wtf:

Quote from: Kitz Kat
I looked if it's the connection on the right rear corner looking at it from the front, it goes to a small round vac chamber or sensor not sure what it does. The bracket for it is bolted to the lower intake and the back of the head.the other hose closer to the middle coming off the intake goes to the pvc on the right vc.
I just looked at the pic again I can see the the part I meant.
  Could you please show me what you mean in the pic?  i.e. circle the areas?

Again, thanks all for the help.  This is driving me bonkers.

Also, the shmuck that did the job also damaged a new radiator.
(http://www.cougarxls.com/pf/saltdamrad.jpg)
Is there a way to fix this?
Title: Vacuum Sucks.... but where?
Post by: CatCarMan2012 on June 01, 2009, 11:59:35 AM
The plug your holding looks like the one for the IAT sensor.
Title: Vacuum Sucks.... but where?
Post by: Kitz Kat on June 01, 2009, 01:04:14 PM
Circled in white. It's between the firewall and block, looks like some kind of vac chamber or sensor.
Title: Vacuum Sucks.... but where?
Post by: cougarXLS on June 01, 2009, 01:42:42 PM
Quote from: Kitz Kat;275438
Circled in white. It's between the firewall and block, looks like some kind of vac chamber or sensor.

Thanks.  I'll check it out.