[T3] Irregular Idle....again...

[J. Jonik]

Bobsnotch wrote.....Sat, 10 Nov 2012 07:23:52 -0500 (EST)
From: Bobsnotch at aol.com

Sounds like you got most of them. I'd check for a vacuum leak where  the 
intake runners bolt onto the cylinder heads, since you've at least had the  
3-4 side tin off (to replace the oil cooler seals). Also check the ends of the 
 hose(s) to the distributor, as they like to crack with age. Same thing 
with the  hose to the MPS. I know this might be out in left field, but also 
check the  front cover on the IAD for leaks. I know it's a long shot, but it's 
not unheard  of.  
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Reply:    Thanks.  I actually did check the two top screws on the back (front of car direction) of the Air Distributor. Tight as can be. Will check bottom two tomorrow.
 I squirted starter fluid around those manifold hose things...no sign of air leaks.
 Hose from dist. vacuum advance to Air Dist is tight and in good shape.
 Hose from ACR to Air Distributor was double-checked...and now seems air tight.  Old hose though.
 Changed head temp sensor with another one.  Zero difference. Still same irregular idle.
 Pressure Sensor hose looks and feels tight.  Take it off, things go bad. Back on, ok again, except for the up and down idling.
 Traded ignition wires with a spare (old) set.  No difference at all.
 Moved Throttle Valve Switch to all sorts of settings. Nothing changed. No difference in idle noted.  Should there have been a difference?

  Ah...but what about this?   As a test (of I don't know what) I detached the ground wire on top of the engine, near the ACR, and Nothing Changed.   Shouldn't the engine have died or something?   What's that ground wire for anyway?  

But....is this a clue?  ------->   After turning engine off for maybe ten or 15 minutes, then starting engine again...it always idles just fine....for about 15 to 25 seconds.  Then the irregularity starts again.  It's as if something warms up again, then doesn't do its job of maintaining regular idle..

I took out the ACR.  Set the adjustment screw to right between - and +...and made sure nothing was sticking. Everything moves freely.   No difference in bad idle. Where should that adjustment be? How to know if it should be more plus or more minus?

Tomorrow, will check to make sure 1-2 side manifold is bolted down tightly. Maybe take it off to check the seals etc.

 Is the thinking that this MUST be an air-vacuum issue?  Not some electronic component?   
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



Bob 65 Notch  S with sunroof and IRS (Krusty)
64 T-34 Ghia  (Wolfie)

Date: Sat, 10 Nov 2012 07:23:52 -0500 (EST)
From: Bobsnotch at aol.com
To: type3 at vwtype3.org
Subject: Re: [T3] Irregular Idle....again...

 
In a message dated 11/9/2012 5:57:48 P.M. Eastern Standard Time,  
j_jonik at yahoo.com writes:

But, now (coincidental with that stud job?) the idle is kind of like 
someone's  sending Morse Code messages with little pushes on the throttle.   No  
backfires.  It's a frequent, regular up and down, not slowly up then  down.  
When revved just a bit, or a lot, no irregularity is  evident.  Engine 
sounds great otherwise, and starts very easily.

[  Had to interrupt the search for that problem when it became clear that 
the oil  cooler seals had to be changed.  That's done, everything  
reconnected.  Same old idling problem though. ]

-Changed Pressure  Regulator, twice, with good spares.  No difference to 
speak  of.   A little, but hard to tell.
- Cleaned spark plugs.
-  Cleaned and messed with distributor...different points, different 
condenser,  different
distributor body itself, and different trigger  contacts.   Vacuum adv. 
passes the suction test  No difference noted.
- Hose from AAR to Air  Distributor was loose.  Ah Ha!   Trimmed both ratty 
ends a  little and re-installed tightly.   No difference noted re/ idle..
-  Put hose clamps on those fat manifold hose sections.  Maybe a percent  
better, but not a fix.

Have not, yet, removed and cleaned, or changed,  the AAR....but screws and 
nuts are tight.    Still can't find info  on how to adjust that little set 
screw inside.

I can't find the year or  so old raps here about Irregular Idle.  I need a 
reminder about What Are  the Most Likely Suspects that might cause this.



Sounds like you got most of them. I'd check for a vacuum leak where  the 
intake runners bolt onto the cylinder heads, since you've at least had the  
3-4 side tin off (to replace the oil cooler seals). Also check the ends of the 
 hose(s) to the distributor, as they like to crack with age. Same thing 
with the  hose to the MPS. I know this might be out in left field, but also 
check the  front cover on the IAD for leaks. I know it's a long shot, but it's 
not unheard  of.  

Bob 65 Notch  S with sunroof and IRS (Krusty)
64 T-34 Ghia  (Wolfie)
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