The retard port on the vacuum advance unit (the vacuum port on the
back of the vacuum cannister closest to the distributor) is hooked up
to the main manifold vacuum -- the same vacuum outlet that goes to the
brake booster. The front port of the vacuum advance unit (the one
that is on the outside of the unit -- the front side -- pointing
toward the radiator) is hooked up to the venturi port on the back side
of the throttle body. The vehicle has a nice diagram on the underside
of the hood, and it is hooked up correctly.

The timing is exactly as described in bentley, there is a small O
for top dead center and a v shaped goldish colored mark to the left of
the O --- to the left three degrees. The label under the hood says 3
degrees plus or minus (+/-) 2 degrees.

I wish I had it mistimed, after the timing belt was installed by a
good mechanic, who timed it, I checked the static timing (with the
marks as described in Bentley) just to make sure that it was on
correctly, and at the static timing points, the O symbol for top dead
center was right in the middle of the timing hole. The three degree
mark was also viewable to the left the the top dead center mark.

Always wondered what decent mileage would be on a CIS engine which was
running correctly.

I got 30+ with my 80 Rabbit that did not have good mileage 4th gear.
My 84 GTI with an economy 5th would get 34 with more power.

My Bentley figure 4-11 says 3 degrees after which is to the right of
the 0 mark. The Bentley on page 68 states that the mark to the right
about 6mm is correct for 3 degrees retarded. I do not see anything in
my manual that says 3 degrees advanced. I do see some get 6 BTDC, 7.5
BTDC and 3 ATDC. B is to the left, A is to the right. Right meaning
the firewall and left meaning the radiator.

I check the flywheel timing mark with a long screwdriver in cylinder
1. I slowly turn the crank and watch for TDC. I confirm that the marks
on the flywheel are correct.

On 3 Apr 2007 10:24:48 -0700, "jfruniontown" <rothring (AT) peoplepc (DOT) com>
wrote:

Re BTDC and ATDC --- I goofed in the prior post --- My top dead
center is a very clear O, and my timing mark is a very pronounced and
clear V cut (goldish in color) to the right (toward the firewall). I
goofed when I said left. In any event the engine is timed to 3 degrees
ATDC as per the diagram and bentley.

"jfruniontown" <rothring (AT) peoplepc (DOT) com> wrote

Yes you have that correct, except that it may not burn off the deposits, it
may only compensate for them!
The cleaner will help rid your engine of deposits, if there are any.

It is important!

"dave AKA vwdoc1" is the man. I followed his instructions and used
the seafoam. I drove the vehicle for a week, (about 130 miles)
(using about 5 gallons of gas) with the seafoam added to the gas tank,
and today used the thru the manifold method of cleaning out the top
end deposits, slowly pouring about 5 oz of the seafoam into the intake
via the vacuum pipe which leads from the manifold to the valve cover.
Then shutting it off, waiting the requisite 5 minutes and restarting
it and then running it hard. The stumble hesitation problem
disappeared. This was on a short test run, but it disappeared and I
could not replicate it (the stumble). Usually I can make the vehicle
stumble or hesitate by barely opening the throttle to cause the vacuum
advance to advance the timing.
Isn't in nice when there is a long thread, with a solution at the
end, rather than leaving a reader hanging.

Report back after driving a few thousand miles. That is pretty good
trick Dave shared.

On 8 Apr 2007 15:44:45 -0700, "jfruniontown" <rothring (AT) peoplepc (DOT) com>
wrote:

WHO ME?
Did I win anything? lol

Yeah let us know what happens over time. ;-)

It is the "Italian Tune-up" that helped....really! <g>
I always think that the VW engines need to be driven hard instead of
pampered. My '83 GTI engine still runs smooth and powerful after 230K
miles. I drive it hard but not abusively and it does not need those
cleaners.
AND personally I like the inexpensive fix! ;-)

congrats and thanks for the followup report.
dave
(One out of many daves)


"Jim Behning" <jimbehning (AT) doesthisblockpork (DOT) mindspring.com> wrote

On the subject of vacuum advance and this car, i was running a mirror
of this subject on bentley's forum. I put up some photos of the
advance unit i took off this vw a week & 1/2 ago, (bad unit) and a
good unit. I also posted photo's of stationary, retarded and advanced
positions on a junk yard distributor with the good vacuum advance unit
mounted thereon. Again I thought in the beginning that my sole
problem was the advance canister. I realize that you know good from
bad, but if you have the time the photo's are decent and hopefully
helpful to other readers. Also appropriate attribution was given.

I mess up links all the time but I think this is the link.

http://tech.bentleypublishers.com/th...29631&tstart=0