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

[Jim Adney]

On 10 Nov 2012 at 16:06, J. Jonik wrote:

>  Moved Throttle Valve Switch to all sorts of settings. Nothing changed. No difference in idle noted.  Should there have been a difference?

I have a FAQ on how to adjust the TVS properly. Moving it around 
randomly only muddies the waters.

>   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?  

Do you mean the AAR (Auxilary Air Regulator?) There are a bunch of 
ground wires on top of the engine. I don't remember which are which, 
but not all are necessary for the engine to run.

> 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.. 

That's interesting, and it points to something changing with warmup, 
but tell us how much variation you're seeing. You may be noticing 
something that's completely normal with these engines.  

> 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? 

I really wouldn't mess with that adjustment. You won't hurt anything 
by doing so, and you might be able to get better temp compensation by 
spending a lot of time at it, but it's likely to take a whole lot of 
time and I don't think it will ever change the "problem" that you're 
trying to fix.

> 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?   

Or it may not actually be a problem at all. These engines never idled 
as evenly as a modern engine. 

Or it could be an ignition problem. Have you looked at the spark 
plugs, or the points, or the lubrication of the mech advance?

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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