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Re: [T3] Cold Start Valve on a 72 fi square


On 26 Apr 2001, at 6:39, dubdriver wrote:

> I've had this same problem.  The pump will not build any pressure
> while cranking, thus no start or very difficult starting.  I found the
> wire push on wire connector loose and it corrected the problem.  I
> think in his orignial post, he stated he had just returned the engine
> to it's original state (FI).  It's likely that this wire was removed
> along with the rest of the FI by the previous owner

I respectfullly disagree. The pump will run any time the engine 
turns over; it knows when this is happening because the trigger 
points in the distributor are opening and closing. In addition, the 
pump will run for ~1 sec after turnon even if the starter wires are 
disconected and the engine isn't turning over. 

If all the FI wires are removed from the starter, the system works 
just fine unless things get really cold, which I don't think applies 
here (he's in Chicago, I'm about 100 miles north of him.) This 
probably IS a problem with the fuel system being full of air after 
cooling down, but the cause of this will have nothing to do with the 
CSV wiring.

It is most likely that the heat soak after shutdown is causing his 
gas to boil and that subsequent cooling down draws in air which is 
there the next time he tries to start the engine.

In reality we don't have enough facts yet to make a certain 
diagnosis, but there is a simple test that is useful: Charles, drive 
your car normally and park it for the night in such a way that you 
are pretty sure that it will be hard to start the next morning. Let the 
engine cool off completely then go out and start the engine just 
before you go to bed. Presumably it will be hard to start.

Once it starts, let it run just long enough to smooth out (30 
seconds should be enough) and shut it off. You DON'T want the 
engine to warm up.

What you have done is to refill all the fuel lines without getting 
anything hot. The next morning the lines should all still be full and if 
my guess is correct the car will be easy to start. In that case, you 
need to look for and correct small fuel leaks that will also admit air 
as the engine cools.

In the absence of finding the leaks, Charles can simply turn the 
key ON and OFF several times before trying to start and this will 
help fill the fuel loop with gasoline. These leaks can be anywhere 
and can be impossible to find; on my 72 I eventually gave up and 
installed a switch under the dash to allow me to run the pump and 
clear the system of air before trying to start. While this works 
beautifully, it is a bit of a pain and annoying not to be able to get at 
the root of the problem.

If I'm wrong and the car still starts hard the next morning then he 
knows one thing that is NOT his problem and can move on to the 
next question. At current temps in the midwest, however, this still 
won't have anything to do with the CSV.

If your problem continues, I'm really rather close to you and the 
weather is getting nice enough that a drive to WI might make a 
nice diversion.  ;-)

-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

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