"stan" wrote in message
...
Hello group,

Sorry about the length of this post but I hope someone has the time to
read it all!

Our family Mk3 Golf 1.8CL estate (ADZ engine) has developed a misfire
this weekend which seems to occur at a steady throttle opening and at
irregular intervals before clearing itself and running well again.

We've had a few problems in the wet weather this winter which has
resulted in it just stopping altogether and, some time later, starting
again without any problem. After stopping last week when my learner
daughter drove through a deep puddle (I don't think it stopped as a
result of the splash but wouldn't re-start afterwards), we were
recovered home and the breakdown chap suggested a knackered coil. He
could see a huge spark as the ignition (and hence starter motor) were
turned off and for the last few turns of the engine there was enough
energy to produce a nice, fat spark. Otherwise, the spark looked OK
but nothing special.

When removed, I found a crack on the underside so it did look like the
culprit. Having fitted a new one, it seemed to be running very well
for a couple of days.

The misfire only happens occasionally and you notice the idle speed
dropping right down to about 600 (usually idles at 950) before picking
up again. Often, the misfire disappears if I switch off and re-start.

It is also sometimes refusing to start in the morning when cold. My
wife has had it start on the third try but I can only get it to start
if I walk away after a few goes then hit it with a branch (not
really!). It has started if, after failing to, I leave it for five or
ten minutes.

After a day where my wife had it misfiring and stalling all the time
she was out in it, she took it to our local garage who have serviced
and MOT'd it for us and asked them to see if they could find anything
wrong. They found that the rubber hose from the inlet manifold which
leads to the servo was split and taped it up for me to replace. The
breakdown chap had also found this pipe was loose so I had jubilee
clipped it in place.

He also found that the Y-shaped breather pipe that connects the rocker
box, the crankcase breather and the 'air box' was split. While I was
waiting for a new pipe I ran it with the split taped up but had taken
out the small copper wire 'filter' to clean it so it is possible that
some crankcase sludge has been sucked in but I can't believe that
could be responsible for poor running and bad starting.

It has had new distributor cap and rotor arm in January, new plugs in
March and new coil and leads in the last week.

It is very frustrating as it often runs perfectly well and, once it
has started, runs OK for some while. For instance, yesterday I drove
for about an hour in three trips through varying amounts of rain with
no problems at all - perhaps just some lumpiness occasionally. Then,
when we started up to drive home, it kept dying and stalling whilst
driving round the car park and going home!

On Friday morning it only started third go for my wife but an hour
later started first time. Then, in the afternoon, it again took three
goes but, once it had started, started immediately if turned off and
re-tried. In the evening, I tried 6 times with no success, went to get
a plug spanner and tried again - it worked without doing anything!

We've had the car for 6 years and it has now done over 110000 miles
without any real problems until this winter. It has always been a
really good starter until the last week or two.

I'm sorry to write so much but wanted to get as many symptoms down as
I could and I hope someone will be able to offer some suggestions as
I've run out of ideas!

TIA

Mark

I had a mk3 GTi 16v which had a strange intermittent misfire. I took it to
a VW specialist who couldn't find the fault. After alot of research on
several forums someone suggested changing the relay for the ECU and maybe
the fuel pump. I changed the ECU relay first as this was the cheapest
(about £12, 3 or 4 years ago) and this cured my problem.