Intermittent spark on '79 Rabbit

Well, back to the old rabbit. I need to replace the timing belt on my 83
rabbit, so I need to get the 79 Rabbit up and running.
Anyway, I was using the Bentley manual to diagnose the problem (no spark in
the high tension wire from terminal 4 as measured by timing gun) , and I
think I found it. The voltage between terminal 1 and terminal 15 is only 7
volts, and according to the manual, it should be 9.6V or higher. It then
goes on to say that the problem may be "poor distributor point contact
[unlikely -- they're new and the reading didn't change when I pressed the
points together manually], a shorted condenser [maybe, but it's also new,
although I DID have the coil from my 83 rabbit installed briefly ...] high
resistance in the ignition switch or the wires that connect the switch to
the coil. " Unfortunately, it doesn't say how to test these last two items.
It DOES give a spec for the resistance wire -- 0.85-0.95 ohms. I do have a
meter that could read that, but that seems like it would be hard to get an
accurate reading that low anyways.
I did the same voltage test with the wires disconnected from the coil and
got a reading of 12V. BUT the red wire which attaches to terminal 15 on the
coil didn't give me a reading. That is, when I hooked the green wire that
goes to terminal 1 to the red wire that goes to 15 (through the meter of
course), I got no reading, even with the ignition switch turned on. Could
this be the problem? The starter solenoid is putting out 12V, so I'm gessing
that's not the problem.
Any ideas?
And thanks again for all the help you guys gave me with my other rabbit!!!!!

On Thu, 2 Aug 2007 20:57:12 -0400, "Fred Mann"
> wrote:

>Well, back to the old rabbit. I need to replace the timing belt on my 83
>rabbit, so I need to get the 79 Rabbit up and running.
>Anyway, I was using the Bentley manual to diagnose the problem (no spark in
>the high tension wire from terminal 4 as measured by timing gun) , and I
>think I found it. The voltage between terminal 1 and terminal 15 is only 7
>volts, and according to the manual, it should be 9.6V or higher. It then
>goes on to say that the problem may be "poor distributor point contact
>[unlikely -- they're new and the reading didn't change when I pressed the
>points together manually], a shorted condenser [maybe, but it's also new,
>although I DID have the coil from my 83 rabbit installed briefly ...] high
>resistance in the ignition switch or the wires that connect the switch to
>the coil. " Unfortunately, it doesn't say how to test these last two items.
>It DOES give a spec for the resistance wire -- 0.85-0.95 ohms. I do have a
>meter that could read that, but that seems like it would be hard to get an
>accurate reading that low anyways.
>I did the same voltage test with the wires disconnected from the coil and
>got a reading of 12V. BUT the red wire which attaches to terminal 15 on the
>coil didn't give me a reading. That is, when I hooked the green wire that
>goes to terminal 1 to the red wire that goes to 15 (through the meter of
>course), I got no reading, even with the ignition switch turned on. Could
>this be the problem? The starter solenoid is putting out 12V, so I'm gessing
>that's not the problem.
>Any ideas?
>And thanks again for all the help you guys gave me with my other rabbit!!!!!
>
The coil is different in the 83 car.

points coil resistance between 15 and 1 1.7 to 2.1 ohms
1 to 4 7,000 to 12,000 ohms

You read terminal 15 with the ground being ground. That big connection
on the battery marked -. Or the metal that holds the coil, or that
braided wire that attaches to the hood, or bare aluminum on the head.
Terminal 1 is the points which may or may not be closed.

You test high resistence with an accurate multimeter.

You could go to the auto parts store and ask for a ballast resistor
for a 1970 Chevrolet Nova. Attach one end to 15. Attach other end to
positive on battery. Try to start car. You just eliminated the posible
bad wiring from ignition switch to fusebox through resistor wire.

I had a coil wire go bad where it plugs in to terminal 4. I replaced
coil and wire using correct coil.

Like Jim said the ign coil from the '83 is for the electronic ign and not
the same.
The voltage will be lower going to the + side of the coil with just the ign
on. It is designed that way to prolong the life of the ign points.
While it is cranking that voltage should go up to 12 volts AFAIK. It should
get the 12V burst from the starter circuit like the cold start valve does.
I could be wrong though. <:-)

You can temporarly supply the ign coil with 12 volts, but I think your
problem lies in the distributor.
You can open up and close the points and you should get a spark while the
ign is on.
I have seen point contacts with a light film on them creating an open
condition. Lightly sand them with an emery board, like for your nails, and
they start creating a spark.

The condenser NEEDS to have a clean ground that it attaches to. I have seen
too many where they didn't get that ground and the engine had running
problems.
Also distributor rotors can create spark delivery problems to the spark plug
wires.

good luck!
--
later,
dave
(One out of many daves)

"Fred Mann" > wrote in message
...
> Well, back to the old rabbit. I need to replace the timing belt on my 83
> rabbit, so I need to get the 79 Rabbit up and running.
> Anyway, I was using the Bentley manual to diagnose the problem (no spark
> in
> the high tension wire from terminal 4 as measured by timing gun) , and I
> think I found it. The voltage between terminal 1 and terminal 15 is only 7
> volts, and according to the manual, it should be 9.6V or higher. It then
> goes on to say that the problem may be "poor distributor point contact
> [unlikely -- they're new and the reading didn't change when I pressed the
> points together manually], a shorted condenser [maybe, but it's also new,
> although I DID have the coil from my 83 rabbit installed briefly ...] high
> resistance in the ignition switch or the wires that connect the switch to
> the coil. " Unfortunately, it doesn't say how to test these last two
> items.
> It DOES give a spec for the resistance wire -- 0.85-0.95 ohms. I do have a
> meter that could read that, but that seems like it would be hard to get an
> accurate reading that low anyways.
> I did the same voltage test with the wires disconnected from the coil and
> got a reading of 12V. BUT the red wire which attaches to terminal 15 on
> the
> coil didn't give me a reading. That is, when I hooked the green wire that
> goes to terminal 1 to the red wire that goes to 15 (through the meter of
> course), I got no reading, even with the ignition switch turned on. Could
> this be the problem? The starter solenoid is putting out 12V, so I'm
> gessing
> that's not the problem.
> Any ideas?
> And thanks again for all the help you guys gave me with my other
> rabbit!!!!!
>
>

You win, Dave!!
It was the condenser. The ground was weak. When I jammed a screwdriver
between the condenser and the distributor, the engine perked right up. Very
exciting!!
So I just cleaned off the distributor with the wire brush attachment on my
Dremel and screwed the condenser back in real tight. That did it.
When's your birthday?



"dave AKA vwdoc1" > wrote in message
et...
> Like Jim said the ign coil from the '83 is for the electronic ign and not
> the same.
> The voltage will be lower going to the + side of the coil with just the
ign
> on. It is designed that way to prolong the life of the ign points.
> While it is cranking that voltage should go up to 12 volts AFAIK. It
should
> get the 12V burst from the starter circuit like the cold start valve does.
> I could be wrong though. <:-)
>
> You can temporarly supply the ign coil with 12 volts, but I think your
> problem lies in the distributor.
> You can open up and close the points and you should get a spark while the
> ign is on.
> I have seen point contacts with a light film on them creating an open
> condition. Lightly sand them with an emery board, like for your nails,
and
> they start creating a spark.
>
> The condenser NEEDS to have a clean ground that it attaches to. I have
seen
> too many where they didn't get that ground and the engine had running
> problems.
> Also distributor rotors can create spark delivery problems to the spark
plug
> wires.
>
> good luck!
> --
> later,
> dave
> (One out of many daves)
>
> "Fred Mann" > wrote in message
> ...
> > Well, back to the old rabbit. I need to replace the timing belt on my 83
> > rabbit, so I need to get the 79 Rabbit up and running.
> > Anyway, I was using the Bentley manual to diagnose the problem (no spark
> > in
> > the high tension wire from terminal 4 as measured by timing gun) , and I
> > think I found it. The voltage between terminal 1 and terminal 15 is only
7
> > volts, and according to the manual, it should be 9.6V or higher. It then
> > goes on to say that the problem may be "poor distributor point contact
> > [unlikely -- they're new and the reading didn't change when I pressed
the
> > points together manually], a shorted condenser [maybe, but it's also
new,
> > although I DID have the coil from my 83 rabbit installed briefly ...]
high
> > resistance in the ignition switch or the wires that connect the switch
to
> > the coil. " Unfortunately, it doesn't say how to test these last two
> > items.
> > It DOES give a spec for the resistance wire -- 0.85-0.95 ohms. I do have
a
> > meter that could read that, but that seems like it would be hard to get
an
> > accurate reading that low anyways.
> > I did the same voltage test with the wires disconnected from the coil
and
> > got a reading of 12V. BUT the red wire which attaches to terminal 15 on
> > the
> > coil didn't give me a reading. That is, when I hooked the green wire
that
> > goes to terminal 1 to the red wire that goes to 15 (through the meter of
> > course), I got no reading, even with the ignition switch turned on.
Could
> > this be the problem? The starter solenoid is putting out 12V, so I'm
> > gessing
> > that's not the problem.
> > Any ideas?
> > And thanks again for all the help you guys gave me with my other
> > rabbit!!!!!

I have actually had condensors go bad. Maybe they were not bad but had
a poor ground. In any event you now have two Jaguars, I mean VWs
running.

On Sun, 5 Aug 2007 21:47:21 -0400, "Fred Mann"
> wrote:

>You win, Dave!!
>It was the condenser. The ground was weak. When I jammed a screwdriver
>between the condenser and the distributor, the engine perked right up. Very
>exciting!!
>So I just cleaned off the distributor with the wire brush attachment on my
>Dremel and screwed the condenser back in real tight. That did it.
>When's your birthday?
>
>
>
>"dave AKA vwdoc1" > wrote in message
. net...
>> Like Jim said the ign coil from the '83 is for the electronic ign and not
>> the same.
>> The voltage will be lower going to the + side of the coil with just the
>ign
>> on. It is designed that way to prolong the life of the ign points.
>> While it is cranking that voltage should go up to 12 volts AFAIK. It
>should
>> get the 12V burst from the starter circuit like the cold start valve does.
>> I could be wrong though. <:-)
>>
>> You can temporarly supply the ign coil with 12 volts, but I think your
>> problem lies in the distributor.
>> You can open up and close the points and you should get a spark while the
>> ign is on.
>> I have seen point contacts with a light film on them creating an open
>> condition. Lightly sand them with an emery board, like for your nails,
>and
>> they start creating a spark.
>>
>> The condenser NEEDS to have a clean ground that it attaches to. I have
>seen
>> too many where they didn't get that ground and the engine had running
>> problems.
>> Also distributor rotors can create spark delivery problems to the spark
>plug
>> wires.
>>
>> good luck!
>> --
>> later,
>> dave
>> (One out of many daves)
>>
>> "Fred Mann" > wrote in message
>> ...
>> > Well, back to the old rabbit. I need to replace the timing belt on my 83
>> > rabbit, so I need to get the 79 Rabbit up and running.
>> > Anyway, I was using the Bentley manual to diagnose the problem (no spark
>> > in
>> > the high tension wire from terminal 4 as measured by timing gun) , and I
>> > think I found it. The voltage between terminal 1 and terminal 15 is only
>7
>> > volts, and according to the manual, it should be 9.6V or higher. It then
>> > goes on to say that the problem may be "poor distributor point contact
>> > [unlikely -- they're new and the reading didn't change when I pressed
>the
>> > points together manually], a shorted condenser [maybe, but it's also
>new,
>> > although I DID have the coil from my 83 rabbit installed briefly ...]
>high
>> > resistance in the ignition switch or the wires that connect the switch
>to
>> > the coil. " Unfortunately, it doesn't say how to test these last two
>> > items.
>> > It DOES give a spec for the resistance wire -- 0.85-0.95 ohms. I do have
>a
>> > meter that could read that, but that seems like it would be hard to get
>an
>> > accurate reading that low anyways.
>> > I did the same voltage test with the wires disconnected from the coil
>and
>> > got a reading of 12V. BUT the red wire which attaches to terminal 15 on
>> > the
>> > coil didn't give me a reading. That is, when I hooked the green wire
>that
>> > goes to terminal 1 to the red wire that goes to 15 (through the meter of
>> > course), I got no reading, even with the ignition switch turned on.
>Could
>> > this be the problem? The starter solenoid is putting out 12V, so I'm
>> > gessing
>> > that's not the problem.
>> > Any ideas?
>> > And thanks again for all the help you guys gave me with my other
>> > rabbit!!!!!
>
>

Hey Fred,
I like the simple and "free" fixes! lol
Help another out and spread the knowledge! <g>
--
later,
dave
(One out of many daves)


"Fred Mann" > wrote in message
...
> You win, Dave!!
> It was the condenser. The ground was weak. When I jammed a screwdriver
> between the condenser and the distributor, the engine perked right up.
> Very
> exciting!!
> So I just cleaned off the distributor with the wire brush attachment on my
> Dremel and screwed the condenser back in real tight. That did it.
> When's your birthday?

Thanks again Jim and Dave.
Strange that this little tidbit isn't in the Bentley manual. Well now it's
on the interweb.
Unfortunately, I'll be back soon.
Fred


"dave AKA vwdoc1" > wrote in message
...
> Hey Fred,
> I like the simple and "free" fixes! lol
> Help another out and spread the knowledge! <g>
> --
> later,
> dave
> (One out of many daves)
>
>
> "Fred Mann" > wrote in message
> ...
> > You win, Dave!!
> > It was the condenser. The ground was weak. When I jammed a screwdriver
> > between the condenser and the distributor, the engine perked right up.
> > Very
> > exciting!!
> > So I just cleaned off the distributor with the wire brush attachment on
my
> > Dremel and screwed the condenser back in real tight. That did it.
> > When's your birthday?
>
>