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


I will go out before I go to bed and run it for a few seconds to refill all
the lines. I am starting to think it most likely is a fuel vaporization
problem since I drove round town for about 45 min then parked the car for
about 3ish hours and I had the same symptoms that I have in the morning.
Also, I tried turning the key on and off 1st and that made the problem a
little better b4 starting, but it was still there. The fuel system is
holding the pressure since I have a fuel pressure guage permanently mounted
and it reads 29 psi even an hour or two later. I will check in the morning
too to see if it still has held the pressure overnight.

Just keep coming with the suggestions. I thank everyone for such great
suggestions. Hope I can get it fixed :)

I thought of one idea...if it is fuel vaporation, could I put high temp fuel
line heat sheaths over the lines to try to deflect the heat. Would this be
worth a try?

As for air leaks, where should I check and how, since I put all new lines
and I spot checked every clamp for leaks for a while after getting
everything together and running.

Thanks,

Charles

-----Original Message-----
From: Jim Adney [mailto:jadney@vwtype3.org]
Sent: Thursday, April 26, 2001 9:54 AM
To: type3@vwtype3.org
Subject: 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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