[T3] Cold Starting Problem

[Jim Adney]

On 22 Dec 2010 at 17:03, rcrogers1 at peoplepc.com wrote:

> My '73 FI Squareback seems to have developed a cold weather starting
> problem.  I have set the valves, installed the distributor that Jim
> repaired, set the timing, checked that all of the wires are connected
> and set the fuel pressure to 28lbs.  It takes five or six tries to get
> started.  Once the engine is warmed it starts much better.  One
> peculiar thing-It seems to respond better (start) if I pump the
> accelerator.  I don't know why that would be in an FI car.  

First off, what is "cold" for you?

When you set the fuel pressure, was it off? Was it stable while you 
watched it? The pressure regulators VERY seldom need adjustment. I've 
NEVER had to re-adjust one, unless it had been tampered with.

Try this: Next time you park the car, let it cool off for a few 
hours, then restart it and let it run just long enough to get all 
cylinders firing, less than 1 minute. Then let it sit for a few more 
hours, or overnight. Next morning see if it starts right up like it 
should.

If it does, the solution is to add a switch under the dash to run the 
fuel pump for a few seconds before you try to start the car. I have 
these switches in each of my cars and I sell a kit to add this to any 
FI type 3 ($10 for MT, $11 for AT.)

This MAY be a hint that your fuel pump is about to crap out. They're 
all starting to do this by now. There's a small rubber bit inside 
there that serves as a check valve and after 30+ years, those bits of 
rubber are starting to crumble. If/when that happens to you, the car 
will no longer run at all, but sometimes we get some warning shots 
before the whole thing disintegrates.

I can rebuild the pump and replace the rubber bit with a Teflon piece 
that I machine to fit. The cost for this is $75 plus return shipping. 
The rebuilt pump will be more robust than the original.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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