[T3] I think I found my stalling problem!

[Jim Adney]

On 30 May 2022 at 10:08, Phil Hof wrote:

> I noticed the fuel pressure dropped near zero, followed by the sputter and
> stall.  At first I assumed the pressure dropped BECAUSE of the stall, but
> it looks to be the opposite!  One stalled, the pressure stayed low during
> cranking.
> 
> Faulty fuel pump?  I jumped terminal 19 to ground, and the pump operated. 
> I could see it stayed steady at 28 psi, and with the remote switch she
> started right away and was stable.

There are several possible broken links in this chain. The transistor in the 
brain is certainly one, but two others come to mind:

Check the connection in the engine bay where wire 19 connects to the main 
rear wiring harness. More than once, I've seen where these wires had been 
disconected and reconnected, but with the two connectors sliding NEXT to 
each other rather than one INSIDE the other. That can make an intermittent 
connection.

I had a '72 that lost power without explanation after driving for sometimes 
minutes, sometimes hours. Eventually, I discovered, by attaching a voltmeter 
to various spots in that chain, that the pump relay was faulty. It would make 
the correct "klunk" but the "klumk" didn't result in power coming out the other 
side. I opened it up and burnished the contacts and it ran perfectly for years, 
until the '72 body rusted out.

The first thing to check would be to put your fingers on that relay and see if 
you can feel the "klunk" each time you turn the key ON or OFF. And verify 
that it clicks when you turn the key ON and clicks off ~1 second later. (That's 
without your jumper in place.)

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