Re: [T3] Severe engine problems...?

[Jim Adney <jadney@vwtype3.org>]

On 10 Aug 2003 at 6:07, Chris J Valade wrote:

>        I tested the resistance of the SP wires and from the dist cap end
> to the SP wire end, here is what I got with the volt ohmmeter set on 2000
> ohm:
>  
>                         1                2                3                4
> SP wire            1995          1979          1953         1984
> dist to wire        1991         1982          1954         1971

I don't know what the second line represents.  ???

> Could the length of the wires account for the drop in resistance?

There's a fairly loose tolerance on these resistances, so some variation should 
be expected. I'm puzzled by the fact that these all seem about 2x what I 
expected. On our wiresets the resistance is all in the SP connectors, which 
should all be ~1000 Ohms, but it's possible that you also have some special 
dist cap connectors which have another 1000 Ohms in them. Look at your wires 
and note that he wire actually plugs into the end of the SP connector; now just 
UNSCREW the SP connector from the end of the wire and see how it is attached.

>         Isn't it: volts X resistance = amps?

Amps = volts/Ohms

>         What gauge of wire should be hooked up to the AAR?  Also, neither
> of the ones I've got have a wire coming out of them, but they do have the
> location for the wire: how should I fit the wire into them, or is it not
> possible to do so and I have to buy a new one?  Both of the ones I have
> caused the fuse to blow.

If your wires have been cut off flush with the AAR then I think you're out of 
luck. You could try taking the AAR apart, but I don't know if you'd have any 
luck with that. I've never attempted it, but we have some good epoxy here and 
I'd be willing to try if you want to send me one of your "dead" AARs. It would 
be interesting to see how these are made inside.

Any wire should be fine; I'd guess that ~20AWG was the original size.

>         Also, with the AAR I've been connecting the hose from it to the
> IAD to the lower port on the AAR--does it matter which one, and if so is
> this right?  Perhaps I have the wrong sort of IAD too since where the
> port is and where it is on the AAR causes the hose to become
> crimped/creased/bent and only have about 1/4 the space it has when
> straight, and I notice a difference in the idle when I try to straighten
> it by hand.

Sounds like you have it right, although the AAR should work either way. It's 
just that the plumbing would be more awkward the other way.

>         From what I could see I do have the front cover plate, but I'm
> uncertain.  Should I be able to see it when looking down on the engine?

Yes, it just in front of the IAD. Bentley ch 3, fig 6-1, front cover plate.

>         Yeah, I do have that ~1/4" diameter rod for the flaps, so that
> will help when I get into checking those out.

Good, but that almost certainly means that the flaps are there, too. So now you 
have to find out whether the flaps are wired open or have fallen shut.  

>         As regards the kickdown switch, I think I may not be
> understanding you so...  On my throttle there is only the return
> spring, also I can push it until the flap hits that piece on the IAD
> which stops it. 

There should be 2 springs on the AT assembly. One spring anchors toward the 
rear of the engine, near the AAR, and is the throttle return spring. The second 
spring is a compressed spring which rotates WITH the throttle shaft and its 
assembly on the left side of the IAD. Once the flap hits the stop on the IAD 
the throttle cable can still pull farther, compressing this spring and letting 
another flap hit the KDS. This spring can be seen on the left side of the photo 
in ch 4, fig 7-11.

>         How do I check for low voltage on the voltage regulator relay?

Put a voltmeter between a powered fuse terminal and ground. With the engine 
warmed up after a drive rev the engine and note the max voltage that you see. 
This should be above 14V. If it is below 13.5V replace the voltage regulator 
with a Bosch 30-019.

>         I'm still concerned about the vacuum hose on the dist.  When I
> suck on it with my mouth creating as much vacuum as I can the plate does
> move, but then slowly returns (I keep the hose plugged with my tongue). 
> I even tried this while the car was idling and, like I mentioned, I don't
> hear, see, or feel any difference when I take it off, plug it, or suck on
> it.

It sounds like it has a slow leak, which sounds small and could just be in the 
other end of the hose connection. If you suck on this while the engine is 
idling you should hear a dramatic speedup of the engine. Are you saying that 
you don't? You should also be able to watch the timing advance if you use your 
timing light at the same time you suck on the hose.

Look inside your dist. there is an arm that comes out of the vac adv can and 
attaches to the breaker plate in the dist. When you suck on the hose the arm 
should move and the whole breaker plate should rotate slightly, moving the 
points slightly around the dist. There is a 3 digit number stamped on the vac 
can arm; what is that number?

>         Would timing, a faulty dist, or anything else cause both #2 and 4
> to miss?  Or would it have to be an unrelated problem for both, i.e. if I
> fix one the other will still miss?

It's either something which these two have in common, or two separate faults. 
Look over and clean off your dist cap, inside and out. Look for spark tracks or 
cracks in the cap.

>         How did I do this time?  Better=)

Yes, much better. Thanks!  ;-)

-- 
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

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