Re: Cold Weather Start

[MARK DAVISON <markaab@global2000.net>]

Hi Rich:

At 05:18 PM 10/31/96 -0600, you wrote:

>'87 16v...*Heinous* cold start problem!! It literally gets worse as the
>temperature gets colder (and the longer the time between starts). I went
>out yesterday after work (9.5 hours of being parked), and it took almost 10
>minutes of on-and-off cranking to get it to turn over  and start. When it
>finally did start, it died when I engaged in reverse. Restarted after a
>couple of tires, and then had no problems.
>
>This morning after 12 hours in a garage, it took just a couple of tries to
>start, but still took some work to do.
>
>Any thoughts?? ( yes, I am pretty car illiterate, but that's one of the
>reasons I sub to this list!!  >;->  )

Sounds like your Cold Start Valve (CSV) may not be working correctly. 
It's an electrical solenoid valve that injects extra fuel into the intake 
manifold during cold starting. 

There is a device called the Thermo Time Sensor (TTS) that senses the
temp of the coolant and if it is cold it sends an electrical signal to the
CSV to inject more fuel when cranking. That's the 'Thermo' part. It also 
artificially heats when you crank the ignition so that after extended cranking
it thinks it's hot and stops sending the signal to the CSV. That's the 'Time'
part.  This is to prevent flooding.

So, there are at least three possible failure modes:

1. TTS not working - the coolant is cold but it is not sending the signal to 
the CSV as it should.

2. CSV not working - it is getting the signal to open and spray extra
fuel but it is not.

3. Bad wire - either between the TTS and CSV or the ignition and TTS.

The Bentley manual outlines the testing procedure quite well but here is
a condensed version:

Remove the main wire from the coil to prevent the car from starting. 
Unclip the plug from the CSV and connect  a voltmeter to the harness
that plugged into the CSV. Crank the starter (remember, COLD engine) 
and you should get 12 volts or pretty close for up to about 10 seconds.
Remember to check polarity. If not then there is no signal telling the valve
to open. Do a visual check of the wiring between the CSV and the TTS. If
it looks OK then the TTS is probably bad, either test or replace.

If you did get voltage then the CSV is getting the signal to open but
may not be opening. Remove the CSV from the manifold, ground the 
body of the valve to the manifold, aim the nozzle into some sort of 
container to catch the fuel. Leave the fuel line attached to the CSV, 
and reconnect the wiring harness. Let the car sit for about 15 to 30
min for the TTS to cool down (remember, it heats up as you crank).
Crank the starter and the valve should spray fuel (since it is getting 
an electrical signal, we just tested for that) for sometime up to about 
10 seconds. If it does not spray then the CSV is bad and should be
replaced.

If it does spray then it is workng find and your problem lies elsewhere.
If you have any questions please email me. I hope this helps.

Mark
Adirondack Auto Brokers
"Your VW/Porsche Parts Source"
Phone (518) 882-6534
Fax (518) 882-1914
Email markaab@global2000.net
VW Web Site http://www.lgicsn.com/vw
Porsche Web Site http://www.lgicsn.com/porsche

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