Hi all. Got a problem that started suddenly. 81 Scirocco starts and
runs fine so long as engine compartment is cool. Warm things up,
either by running or by sun on the hood (or on the engine with hood
up) and the engine will suddenly seem like it's running on one
cylinder..."chug..chug..chug..", jerking like crazy. Doesn't seem to
make much difference how far the gas pedal is down. Sometimes it will
catch and run smoothly for a short distance, then the problem starts
again. And sometimes the engine will just die.

Not useful to only be able to drive 2 miles in the morning. Does
anyone have a clue what could be wrong?

thx,
nf

fuel
ignition
compression

something is not right! Components need to be tested!

Check for vacuum leaks, especially the large intake manifold boot.
Check the fuel pressure might be a control pressure regulator problem.

What color is the exhaust = black, and does it smell rich?

What have you done to the engine lately? Installed new spark plugs, BOSCH
distributor rotor and cap?
Before or after this problem showed up?


"nutso fasst" <nutsofasst (AT) gmail (DOT) com> wrote

On Wed, 21 Oct 2009 06:49:12 -0500, "dave AKA vwdoc1"
<vwdoc1nospam (AT) pleasehotmail (DOT) com> wrote:

Long shot: check the plug wires... Possibly when they get warm they
'sag' and are arcing against something cutting out a cylinder.

"nutso fasst" <nutsofasst (AT) gmail (DOT) com> schreef in bericht
news:9f23ff56-323f-44a5-9e82-905154edac68 (AT) d9g2000prh (DOT) googlegroups.com...
All what the others say and also check hall sensor in distr.

SFC

On Oct 21, 7:46*am, "SFC" <sf-cill... (AT) hetnet (DOT) nl> wrote:

Thanks very much to all who replied. I should have noted that vacuum
hoses, boots, plugs/wires, dist cap/rotor, FI O-rings, O2 sensor, and
air filter were all replaced recently. Exhaust, even with engine
chugging, looked clean. Note that when the engine went into chug mode,
the tach bounced down on zero.

At some point in the past I had re-connected a broken wire in the
connector to the distributor. But I had not considered the hall
sensor, and don't really know how to test it.

This morning the engine started and warmed thoroughly without issue.
But I didn't drive the car immediately. I shut down and removed the
connector to the distributor. The contacts looked a bit corroded. Not
having a tiny file to go after them with, I inserted/removed the
connector repeatedly to try and ensure contact. I then removed the
distributor cap and removed a bit of oil film from what I think is the
hall sensor with a piece of paper. Then I drove the car.

At first all seemed well, but then the problem returned. Not not as
bad before, though. I was able to limp into the driveway. With engine
still chugging, I lifted the hood. After a few moments the engine
started running smoothly again.

Again I removed/inserted the connector a few times and the engine
started right up. I let it run for a while with hood down, then drove
around the block. No problem.

It remains to be seen if this problem is really fixed. But unless
there's a lot of coincidence going on here, it seems to be related to
the sensor and/or the connector.

nf

nutso fasst wrote:
if the tach drops to zero I think you definitely have an ignition
related issue so if you haven't found it you are on the right track anyway

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Oct 21, 4:53*pm, Nate Nagel <njna... (AT) roosters (DOT) net> wrote:
I'm going to have to keep digging. The car sat in the sun for a few
hours this afternoon and the problem returned.

I had another heat-related problem a few years ago. The starter would
not turn when the motor was hot. Mechanic could not find the problem,
but I did: the wire to the solenoid had cracked insulation and the
wire inside was corroded. I ran 12 gauge wire from the firewall to the
solenoid and all was well.

nf

On Oct 20, 6:51 pm, nutso fasst <nutsofa... (AT) gmail (DOT) com> wrote:
I've had a similar problem, which may not have any relation to your
problem, but is an easy check. The symptoms were identical and random.
Check the group of ground wires that attach to the head using a rear
valve cover bolt as the mounting point (drivers side). Pull gently on
each wire to see if any are broke. They usually break when the front
motor mount goes bad and allows the engine to move more than it should
and strain the wires. Easy fix too.

On Oct 21, 7:08*pm, beav <dek... (AT) yahoo (DOT) ca> wrote:
On the '81 the only ground wires are attached to the EFI manifold, not
the valve cover. They're in good shape. But thanks for the suggestion!

nf

I've not been able to find the culprit. I've only got a couple of
weeks before escrow closes and cannot deal with this issue. If anyone
here knows anyone in the Los Angeles area who wants an 81 Scirocco S w/
256K miles, please let me know.

nf