Currently Undersucked!
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Drifting
Joined: Sep 2004
Posts: 1,638
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Currently Undersucked!
What started as a hard brake petal has progressed to this! I put a vacuum gauge on the line from the manifold to the brake booster - it shows 10 mmhg? or whatever the increment is. i double checked the gauge by putting a migtyvac on it and pulling 15 mmhg - and comparing dials - if they are inaccurate - they are both exactly the same - both show 15 mm hg.
So that pretty much excludes the brake booster - now we are looking for the source of low vacuum.
since it seems to idle fine - no rolling or hunting - and I can't hear any sucking - I am assuming I have no vacuum leaks,
That leaves me leaning toward a timing adjustment - that makes sense to me - seeing as how i just dropped the motor back into the car - and reinstalled the distributor !
The problem is: the ZZ4 motor uses the plastic timing chain cover - and you cannot see the timing marks on it, It doesn't have the little tab that sticks out - so I end up guessing - hard to do it by ear - because the computer is always compensating.
Oh yah - and what the heck does the EST connector look like - I need to disconect it before I can set the timing!
Carl "currently undersucked" Johansson
So that pretty much excludes the brake booster - now we are looking for the source of low vacuum.
since it seems to idle fine - no rolling or hunting - and I can't hear any sucking - I am assuming I have no vacuum leaks,
That leaves me leaning toward a timing adjustment - that makes sense to me - seeing as how i just dropped the motor back into the car - and reinstalled the distributor !
The problem is: the ZZ4 motor uses the plastic timing chain cover - and you cannot see the timing marks on it, It doesn't have the little tab that sticks out - so I end up guessing - hard to do it by ear - because the computer is always compensating.
Oh yah - and what the heck does the EST connector look like - I need to disconect it before I can set the timing!
Carl "currently undersucked" Johansson
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Did you push in the brake pedal during this test? The vacuum port to the front side of the booster diaphram doesn't open unless you move the pedal a bit.
Also, if you try to pull a vacuum on the booster, it will seem dead, but it really just takes quite a few pumps, because of the air volume in there.
Also, if you try to pull a vacuum on the booster, it will seem dead, but it really just takes quite a few pumps, because of the air volume in there.
Le Mans Master
Joined: Jul 2002
Posts: 5,818
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From: Alive and well in Burlington NC
Originally Posted by 4Ever21
Well the EST connector is on the driver side near the power brake booster. Its a round connector and it comes out of a harness of wires.
Single wire connector, tan wire. Should be taped outside the conduit covering the wire harness and yes you need to disconnect it to set the timing. Without the timing marks it might be tough though.Just checked your year. The location above is for my 91. Not sure where it is on your 86. I remember something about a different location but can't sear to it (shouldn't have killed that brain cell). Someone with an 86 should chime in.
Last edited by Steel Blue 91; Aug 30, 2006 at 04:58 PM.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
You are going to be dead in the water trying to set your timing without timing marks. You are going to have to establish TDC for #1 and get and install an adjustable timing tab.
RACE ON!!!
RACE ON!!!
