[T3] Lurching Hesitation Prob...solved again...

[Jim Adney]

On 11 Apr 2013 at 17:19, J. Jonik wrote:

> Back in December, after much work trying to solve lurching, hesitation
> problem.  On advice of a pro, I switched  the Voltage Regulator and
> problem disappeared.   (T-III 71 w/ 73 engine  FI) 
> 
> BUT...four months later, three days ago, lurching reappeared out of
> the blue. Fine the day before...lurching when I drove off the next
> day.  No advance warning.   Checked timing etc, cleaned plugs, checked
> all the wires, etc...and then thought to find old info in Type III
> emails.  Bingo....there was the reminder about Voltage Regulator.  
> Tried one of my spares...lurching got worse.   Took one out of parts
> car (though sitting for ages) and it works like a champ...long city
> traffic test run too. 

There's very little point in trying various old ones randomly. There 
are simple tests you can do that are spelled out in my charging 
system writeup that you can do to test the one IN your car. 

> Question is:   Is there something besides just old-age breakdown that
> can cause a Voltage Regulator to go bad?   Is this just a
> coincidence?  Should I get a Brand New one just to be safe? 

The old original style just wears out. The new ones, the type that 
looks completely different on the outside, should last forever, as 
long as they don't get abused, but I don't think anyone has enough 
experience with them yet to be sure. I have a very few of the old 
original style that I have modified to give longer life, but even 
those will have a finite lifetime.

>  And, I have about three more spares?   Any way to test them outside
> of the car?...or do I have to install to test? 

Spares, or used examples? Used ones are of very little value. Most 
will be bad and the rest will be bad soon. Buy a new one: Bosch 
30-019. I stock them if you can't find one locally.

If you have a generator test bench and a spare generator and battery, 
they can be tested there, but that's not something you're likely to 
have. One thing you CAN do is remove the cover and put a piece of 
paper between each of the contacts that are closed, insulating them. 
Then turn the unit upside down and measure the resistance of the 
wirewound resistor underneath. If it's open, the VR is dead.

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