[T3] 71 Squareback MT/FI - Intermittent Engine Stopping

[Wisconsin Spryers]

---------- Forwarded message ----------
From: Jim Adney <jadney at vwtype3.org>
To: type3 at vwtype3.org
Cc:
Bcc:
Date: Tue, 09 Jun 2020 17:40:31 -0500
Subject: Re: [T3] 71 Squareback MT/FI - Intermittent Engine Stopping

Do you get the 2 relay clicks when you turn the key ON, even when it won't
start. If so, that's a good sign that the FI is still working. If not, then
we're
looking for problems with the FI power relay.

> I hear (and feel) the 2 relay clicks when I turn the key ON.

If you hear 2 clicks, try holding the primer switch in the momentary "prime"
position while you try to start the engine. If it starts then, but dies
soon after
releasing the switch, then your fuel pump relay is going bad. I have good
used OG replacements.

> While holding the switch in the momentary "prime" position I was able
> to start the engine and it continued running when I released the switch.

If you have a meter you can use to measure the fuel pump current, that
might help. If the pump is drawing excessive current, that might cause the
pump relay to overheat. I think normal current is 4 A or a little less. 8 A
is
definitely too much, and might mean that the pump is working against some
extra load, like gas residue inside it. Some SeaFoam gas additive for a
couple tanks might help dissolve that.

> I'll throw-in some SeaFoam gas additive. This problem just started after
> filling up with almost 9-gallons of gas last week.
>
> For the amperage measurement, I connected the meter terminal "87"
> on the fuel pump relay and the wire (I disconnected from that terminal)
that
> leads to the + fuel pump terminal. I started the engine and was only
> reading between 1.30A & 1.35A.

If the FI seems good, I'd be wondering about the ignition coil or maybe the
FI
trigger points. This doesn't really sound like a FI problem, but it could
be. Do
you still have the black Bosch coil? If so, that's good. Other options are
probably less reliable.

> I'm still using the black Bosch Ignition Coil. And I don't recall if the
trigger
> points were my original ones when we swapped out my '73 distributor for
the
> correct '71 version when "de-frankensteining" my engine back in 2018.

I have a little rig that you could borrow to watch for spark while driving.
If the
engine stops but you still have spark, the problem is probably fuel
related. If
there's no spark, then you need to look at the ignition system.

> I'd be interested in borrowing your "spark" monitor. I'll be doing a few
more
> around-the-neighborhood trips to see if this problem occurs again.

Thanks,

-- Richard Spryer



--
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.vwtype3.org/pipermail/type3-vwtype3.org/attachments/20200610/04808fa9/attachment.html>